WO2019194231A1 - Protein composition and method for producing same - Google Patents

Protein composition and method for producing same Download PDF

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Publication number
WO2019194231A1
WO2019194231A1 PCT/JP2019/014834 JP2019014834W WO2019194231A1 WO 2019194231 A1 WO2019194231 A1 WO 2019194231A1 JP 2019014834 W JP2019014834 W JP 2019014834W WO 2019194231 A1 WO2019194231 A1 WO 2019194231A1
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Prior art keywords
amino acid
seq
protein
sequence
fibroin
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PCT/JP2019/014834
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French (fr)
Japanese (ja)
Inventor
一樹 坂田
健太郎 ▲高▼橋
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Ｓｐｉｂｅｒ株式会社
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Publication of WO2019194231A1 publication Critical patent/WO2019194231A1/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F4/00—Monocomponent artificial filaments or the like of proteins; Manufacture thereof
    • D01F4/02—Monocomponent artificial filaments or the like of proteins; Manufacture thereof from fibroin
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P21/00—Preparation of peptides or proteins
    • C12P21/02—Preparation of peptides or proteins having a known sequence of two or more amino acids, e.g. glutathione

Definitions

  • the present invention relates to a protein composition and a method for producing the same.
  • Patent Document 1 discloses an animal fiber molded article having high mechanical properties such as stress-strain characteristics obtained by compression molding an animal fiber aggregate. .
  • Such a protein composition such as a protein molded body is desired to have various functions in accordance with application fields and the like when applied to various fields.
  • the method of imparting functionality by directly chemically modifying proteins has problems such as low reaction efficiency, and it is difficult to impart sufficient functionality.
  • An object of the present invention is to provide a protein composition to which functionality is imparted. Another object of the present invention is to provide a method for producing a protein composition that can efficiently impart various functionalities to the protein composition.
  • the present inventors do not directly chemically modify the protein, but mix the modified hydroxyl group-containing polymer having the functional group bonded to the hydroxyl group-containing polymer with the protein, thereby adding a functional functional group to the protein composition. It was found that functionality can be imparted.
  • the present invention is based on this novel finding.
  • a protein composition comprising a modified hydroxyl group-containing polymer having a functional functional group bonded to a hydroxyl group-containing polymer, and a protein.
  • Step b) b-1) obtaining a dope solution comprising the modified hydroxyl group-containing polymer, the protein and a solvent; b-2) bringing the protein into contact with the modified hydroxyl group-containing polymer by bringing the dope solution into contact with a solvent removal agent to release the solvent from the dope solution, [12] ]
  • the manufacturing method of the protein composition as described in.
  • step b-2 By desorbing the solvent from the dope solution, the protein and the modified hydroxyl group-containing polymer are hydrogen-bonded, and the protein is coagulated and molded to contain the protein and the modified hydroxyl group-containing polymer.
  • a protein composition having various functions such as water resistance.
  • a method for producing a protein composition that can efficiently impart various functionalities to the protein composition.
  • the protein composition according to the present embodiment includes a modified hydroxyl group-containing polymer in which a functional functional group is bonded to a hydroxyl group-containing polymer, and a protein.
  • the modified hydroxyl group-containing polymer is a polymer in which a functional functional group is bonded to a hydroxyl group-containing polymer.
  • the modified hydroxyl group-containing polymer can be obtained, for example, by reacting a hydroxyl group-containing polymer with a reactive agent having a functional functional group.
  • the hydroxyl group-containing polymer can be used without particular limitation as long as it is a polymer compound having a hydroxyl group.
  • Specific examples of the hydroxyl group-containing polymer include polysaccharides such as starch, glycogen, cellulose, chitin, agarose, hyaluronic acid, chondroitin sulfate, pectin and carrageenan, synthetic polymers such as polyvinyl alcohol (PVA) and phenol resin.
  • PVA polyvinyl alcohol
  • the hydroxyl group-containing polymer is preferably a polysaccharide from the viewpoint of biodegradability.
  • a hydroxyl group containing polymer starch is preferable from a viewpoint of having high solubility in addition to having biodegradability.
  • the functional functional group is a functional group having characteristics (for example, hydrophobicity, hydrophilicity) corresponding to the functionality (for example, water resistance, hydrophilicity, lipophilicity, oil resistance) desired to be imparted to the protein composition, It can select suitably according to the functionality to give to a protein composition.
  • examples of functional functional groups include alkyl groups such as methyl, ethyl, n-propyl, and isopropyl groups, and aromatic groups such as phenyl and naphthyl groups.
  • hydrophobic functional groups such as acyl groups such as acetyl group, propanoyl group, and benzoyl group can be used.
  • the reactive agent having a functional functional group is a compound having a functional functional group and further having a binding functional group capable of binding to a hydroxyl group-containing polymer.
  • the binding functional group may be a hydrogen group or a covalent bond capable of binding to the hydroxyl group-containing polymer, but is preferably a functional group capable of covalently binding to the hydroxyl group-containing polymer. It is more preferably a functional group that can be covalently bonded to the hydroxyl group.
  • isocyanate and acetic anhydride having a functional functional group are preferable since they can be covalently bonded to the hydroxyl group in the hydroxyl group-containing polymer. Is more preferable since the functional group can be introduced.
  • the type of protein is not particularly limited, and may be, for example, a structural protein.
  • the structural protein refers to a protein forming a biological structure or a protein derived therefrom. That is, the structural protein may be a naturally derived structural protein, and a modified protein obtained by modifying a part of the amino acid sequence (for example, 10% or less of the amino acid sequence) based on the amino acid sequence of the naturally derived structural protein. It may be.
  • structural proteins include fibroin, collagen, resilin, elastin and keratin, and proteins derived therefrom.
  • the fibroin may be, for example, one or more selected from the group consisting of silk fibroin, spider silk fibroin, and hornet silk fibroin.
  • the structural protein may be silk fibroin, spider silk fibroin or a combination thereof. When silk fibroin and spider silk fibroin are used in combination, the ratio of silk fibroin may be, for example, 40 parts by mass or less, 30 parts by mass or less, or 10 parts by mass or less with respect to 100 parts by mass of spider silk fibroin.
  • the fibroin according to the present embodiment includes naturally derived fibroin and modified fibroin.
  • naturally-occurring fibroin means fibroin having the same amino acid sequence as naturally-occurring fibroin
  • modified fibroin means fibroin having an amino acid sequence different from that of naturally-occurring fibroin. To do.
  • the fibroin according to the present embodiment is preferably spider silk fibroin.
  • Spider silk fibroin includes natural spider silk fibroin and modified fibroin derived from natural spider silk fibroin. Examples of natural spider silk fibroin include spider silk protein produced by spiders.
  • the fibroin according to the present embodiment is, for example, a domain sequence represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif. It may be a protein containing
  • an amino acid sequence (N-terminal sequence and C-terminal sequence) may be further added to either one or both of the N-terminal side and the C-terminal side of the domain sequence.
  • the N-terminal sequence and the C-terminal sequence are not limited to these, but are typically regions having no amino acid motif repeat characteristic of fibroin and consisting of about 100 amino acids.
  • domain sequence refers to a fibroin-specific crystal region (typically corresponding to the (A) n motif in the amino acid sequence) and an amorphous region (typically in the REP of the amino acid sequence).
  • (A) n motif represents an amino acid sequence mainly composed of alanine residues, and the number of amino acid residues is 2 to 27.
  • the number of amino acid residues of the n motif may be an integer of 2 to 20, 4 to 27, 4 to 20, 8 to 20, 10 to 20, 4 to 16, 8 to 16, or 10 to 16 .
  • the ratio of the number of alanine residues to the total number of amino acid residues in the (A) n motif may be 40% or more, such as 60% or more, 70% or more, 80% or more, 83% or more, 85% or more, It may be 86% or more, 90% or more, 95% or more, or 100% (meaning that it is composed only of alanine residues).
  • a plurality of (A) n motifs present in the domain sequence may be composed of at least seven alanine residues alone.
  • REP indicates an amino acid sequence composed of 2 to 200 amino acid residues.
  • REP may be an amino acid sequence composed of 10 to 200 amino acid residues.
  • m represents an integer of 2 to 300, and may be an integer of 10 to 300.
  • a plurality of (A) n motifs may have the same amino acid sequence or different amino acid sequences.
  • Plural REPs may have the same amino acid sequence or different amino acid sequences.
  • Naturally occurring fibroin examples include a domain sequence represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif. Mention may be made of proteins containing. Specific examples of naturally occurring fibroin include fibroin produced by insects or spiders.
  • fibroin produced by insects include, for example, Bombyx mori, Kwako (Bombyx mandarina), Tenaea (Antheraea palaniii), and ⁇ ⁇ (Eriothyraminey).
  • Silkworms produced by silkworms such as Samia cythia, chestnut worms (Caligula japonica), Chuser moth (Antherea mylitta), Antheraea assama, and vespax (Vespaxia spp.) Hornet silk protein.
  • fibroin produced by insects include silkworm fibroin L chain (GenBank accession number M76430 (base sequence) and AAA27840.1 (amino acid sequence)).
  • Fibroin produced by spiders includes, for example, spiders belonging to the genus spider (Araneus spp.) Such as the spider spider, the spider spider, the red spider spider, and the bean spider, the genus spiders of the genus Araneus, the spider spider spider, the spider spider genus e Spiders, spiders such as spiders, spiders belonging to the genus Spider, spiders belonging to the genus Pronos, spiders belonging to the genus Trinofunda, such as Torinofundamas (genus Cyrtarachne) Spiders belonging to the genus (Gasteracantha), spiders belonging to the genus Spider (Ordgarius genus), such as the spiders, the spiders, and the spiders belonging to the genus Ordgarius Spiders belonging to the genus Argiope, such as the genus Argiope, spiders belonging to the genus Arachnura, such as the white-tailed spider, spiders belonging to the
  • Spiders belonging to the genus Azumigumi (Menosira)
  • spiders belonging to the genus Dyschiriognatha (genus Dyschiriognatha) such as the common spider spider, the black spider spider, the genus Spider genus belonging to the genus Spider belonging to the genus and the genus Spider belonging to the genus Spider belonging to the genus
  • Produced by spiders belonging to the family Tetragnathidae such as spiders belonging to the genus Prostenops
  • Examples include spider silk protein.
  • the spider silk protein include dragline proteins such as MaSp (MaSp1 and MaSp2) and ADF (ADF3 and ADF4), MiSp (MiSp1 and MiSp2), and the like.
  • spider silk proteins produced by spiders include, for example, fibroin-3 (adf-3) [derived from Araneus diadematus] (GenBank accession numbers AAC47010 (amino acid sequence), U47855 (base sequence)), fibroin-4 (adf-4) [derived from Araneus diadematus] (GenBank accession number AAC47011 (amino acid sequence), U47856 (base sequence)), dragline silk protein spiroin 1 [derived from Nephila clavipes] (GenBank amino acid sequence 4) ), U37520 (base sequence)), major ampulate spidro n 1 [derived from Latroductus hesperus] (GenBank accession number ABR68856 (amino acid sequence), EF595246 (base sequence)), dragline silk protein spidrin 2 [derived from Nephila clavata (GenBank accession number AAL32 base sequence 45 AAL32 base sequence amino acid 44, amino acid sequence 44 AAL47)
  • Naturally derived fibroin include fibroin whose sequence information is registered in NCBI GenBank.
  • sequence information is registered in NCBI GenBank.
  • spidin, sample, fibroin, “silk and polypeptide”, or “silk and protein” is described as a keyword in DEFINITION from sequences including INV as DIVISION among the sequence information registered in NCBI GenBank. It can be confirmed by extracting a character string of a specific product from the sequence, CDS, and a sequence in which the specific character string is described from SOURCE to TISSUE TYPE.
  • the modified fibroin is, for example, a modified amino acid sequence based on the amino acid sequence of naturally occurring fibroin (for example, a modified amino acid sequence by modifying the gene sequence of a cloned naturally occurring fibroin). Alternatively, it may be one that is artificially designed and synthesized without relying on natural fibroin (for example, one having a desired amino acid sequence by chemically synthesizing a nucleic acid encoding the designed amino acid sequence). .
  • the modified fibroin is, for example, a modification of the amino acid sequence corresponding to, for example, substitution, deletion, insertion and / or addition of one or more amino acid residues to the cloned natural fibroin gene sequence. Can be obtained at Substitution, deletion, insertion and / or addition of amino acid residues can be carried out by methods well known to those skilled in the art such as partial-directed mutagenesis. Specifically, Nucleic Acid Res. 10, 6487 (1982), Methods in Enzymology, 100, 448 (1983), and the like.
  • the modified fibroin may be, for example, a modified fibroin derived from a silk protein produced by a silkworm, or a modified fibroin derived from a spider silk protein produced by a spider.
  • modified fibroin examples include modified fibroin (first modified fibroin) derived from the large sphincter bookmark silk protein produced in the spider large bottle gland, modified fibroin with reduced glycine residue content (Second modified fibroin), (A) modified fibroin with reduced n- motif content (third modified fibroin), glycine residue content, and (A) n- motif content reduced
  • modified fibroin fourth modified fibroin
  • a modified fibroin having a domain sequence that locally includes a region having a large hydrophobicity index fifth modified fibroin
  • a domain sequence having a reduced glutamine residue content Modified fibroin may be mentioned.
  • the modified fibroin derived from the large sphincter bookmark silk protein produced in the spider large bottle-like gland includes a domain sequence represented by Formula 1: [(A) n motif-REP] m
  • the protein containing is mentioned.
  • n is preferably an integer of 3 to 20, more preferably an integer of 4 to 20, still more preferably an integer of 8 to 20, still more preferably an integer of 10 to 20.
  • An integer of ⁇ 16 is even more preferred, an integer of 8-16 is particularly preferred, and an integer of 10-16 is most preferred.
  • the number of amino acid residues constituting REP is preferably 10 to 200 residues, more preferably 10 to 150 residues, and 20 to 100 residues. More preferably, it is more preferably 20 to 75 residues.
  • the total number of glycine residues, serine residues and alanine residues contained in the amino acid sequence represented by the formula 1: [(A) n motif-REP] m is an amino acid residue. The total number is preferably 40% or more, more preferably 60% or more, and even more preferably 70% or more.
  • the first modified fibroin comprises an amino acid sequence unit represented by Formula 1: [(A) n motif-REP] m , and the C-terminal sequence is represented by any one of SEQ ID NOs: 1 to 3, Alternatively, it may be a polypeptide that is an amino acid sequence having 90% or more homology with the amino acid sequence shown in any one of SEQ ID NOs: 1 to 3.
  • the amino acid sequence shown in SEQ ID NO: 1 is identical to the amino acid sequence consisting of 50 amino acids at the C-terminal of the amino acid sequence of ADF3 (GI: 1263287, NCBI), and the amino acid sequence shown in SEQ ID NO: 2 is the sequence
  • the amino acid sequence shown in SEQ ID NO: 1 is identical to the amino acid sequence obtained by removing 20 residues from the C-terminal, and the amino acid sequence shown in SEQ ID NO: 3 has 29 residues removed from the C-terminal of the amino acid sequence shown in SEQ ID NO: 1. It is identical to the amino acid sequence.
  • the amino acid sequence represented by SEQ ID NO: 4 or (1-ii) the amino acid sequence represented by SEQ ID NO: 4 has a sequence identity of 90% or more. Mention may be made of modified fibroin comprising an amino acid sequence having. The sequence identity is preferably 95% or more.
  • the amino acid sequence represented by SEQ ID NO: 4 is an amino acid sequence of ADF3 in which an amino acid sequence (SEQ ID NO: 5) consisting of a start codon, a His10 tag and an HRV3C protease (Human rhinovirus 3C protease) recognition site is added to the N-terminus.
  • the 13th repeat region was increased to approximately double, and the translation was mutated to terminate at the 1154th amino acid residue.
  • the C-terminal amino acid sequence of the amino acid sequence shown in SEQ ID NO: 4 is identical to the amino acid sequence shown in SEQ ID NO: 3.
  • the modified fibroin (1-i) may be composed of the amino acid sequence represented by SEQ ID NO: 4.
  • the modified fibroin with a reduced content of glycine residues has an amino acid sequence with a reduced content of glycine residues in the domain sequence compared to naturally occurring fibroin. It can be said that the second modified fibroin has an amino acid sequence corresponding to at least one or more glycine residues in REP substituted with another amino acid residue as compared with naturally occurring fibroin. .
  • the second modified fibroin has a domain sequence of GGX and GPGXX in REP (where G is a glycine residue, P is a proline residue, and X is an amino acid residue other than glycine) as compared to naturally occurring fibroin.
  • G is a glycine residue
  • P is a proline residue
  • X is an amino acid residue other than glycine
  • at least one glycine residue in at least one or more of the motif sequences is substituted with another amino acid residue. May be.
  • the ratio of the motif sequence in which the above glycine residue is replaced with another amino acid residue may be 10% or more with respect to the entire motif sequence.
  • the second modified fibroin comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and is located on the most C-terminal side from the domain sequence (A) from the n motif to the domain sequence.
  • the number of alanine residues relative to the total number of amino acid residues in the n motif may be 83% or more, preferably 86% or more, more preferably 90% or more, and 95% or more. More preferably, it is 100% (meaning that it is composed only of alanine residues).
  • the second modified fibroin is preferably one in which the content ratio of the amino acid sequence consisting of XGX is increased by substituting one glycine residue of the GGX motif with another amino acid residue.
  • the content ratio of the amino acid sequence consisting of GGX in the domain sequence is preferably 30% or less, more preferably 20% or less, still more preferably 10% or less, % Or less is even more preferable, 4% or less is even more preferable, and 2% or less is particularly preferable.
  • the content ratio of the amino acid sequence consisting of GGX in the domain sequence can be calculated by the same method as the method for calculating the content ratio (z / w) of the amino acid sequence consisting of XGX below.
  • a fibroin modified fibroin or naturally-occurring fibroin containing a domain sequence represented by Formula 1: [(A) n motif-REP] m , (A) n located closest to the C-terminal side from the domain sequence
  • An amino acid sequence consisting of XGX is extracted from all REPs included in the sequence excluding the sequence from the motif to the C-terminal of the domain sequence.
  • z / w (%) can be calculated by dividing z by w.
  • z / w is preferably 50.9% or more, more preferably 56.1% or more, further preferably 58.7% or more, and 70% or more. It is still more preferable that it is 80% or more. Although there is no restriction
  • the second modified fibroin is obtained by, for example, modifying a cloned natural fibroin gene sequence so as to encode another amino acid residue by substituting at least a part of a base sequence encoding a glycine residue.
  • a glycine residue in GGX motif and GPGXX motif may be selected as a glycine residue to be modified, or substitution may be performed so that z / w is 50.9% or more.
  • an amino acid sequence satisfying the above-described aspect can be designed from the amino acid sequence of naturally derived fibroin, and a nucleic acid encoding the designed amino acid sequence can be obtained by chemical synthesis.
  • one or more amino acid residues are further substituted or deleted.
  • the amino acid sequence corresponding to the insertion and / or addition may be modified.
  • the other amino acid residue is not particularly limited as long as it is an amino acid residue other than glycine residue, but valine (V) residue, leucine (L) residue, isoleucine (I) residue, methionine ( M) hydrophobic amino acid residues such as proline (P) residue, phenylalanine (F) residue and tryptophan (W) residue, glutamine (Q) residue, asparagine (N) residue, serine (S ) Residues, lysine (K) residues and glutamic acid (E) residues are preferred, and valine (V) residues, leucine (L) residues, isoleucine (I) residues and glutamine ( Q) residue is more preferable, and glutamine (Q) residue is more preferable.
  • modified fibroin (2-i) the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, or (2-ii) SEQ ID NO: 6, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 7, SEQ ID No. 8 or SEQ ID No. 9.
  • the modified fibroin (2-i) will be described.
  • the amino acid sequence represented by SEQ ID NO: 6 is obtained by substituting all GGX in REP of the amino acid sequence represented by SEQ ID NO: 10 corresponding to naturally occurring fibroin with GQX.
  • the amino acid sequence represented by SEQ ID NO: 7 is the amino acid sequence represented by SEQ ID NO: 6, wherein every two (A) n motifs are deleted from the N-terminal side to the C-terminal side, and further before the C-terminal sequence.
  • One [(A) n motif-REP] is inserted into the.
  • the amino acid sequence represented by SEQ ID NO: 8 has two alanine residues inserted at the C-terminal side of each (A) n motif of the amino acid sequence represented by SEQ ID NO: 7, and a part of glutamine (Q) residues. Substituted with a serine (S) residue and a part of the amino acid at the N-terminal side was deleted so as to be almost the same as the molecular weight of SEQ ID NO: 7.
  • the amino acid sequence shown in SEQ ID NO: 9 is a region of 20 domain sequences present in the amino acid sequence shown in SEQ ID NO: 11 (however, several amino acid residues on the C-terminal side of the region are substituted). Is a sequence in which a His tag is added to the C-terminal of the sequence repeated four times.
  • the value of z / w in the amino acid sequence represented by SEQ ID NO: 10 (corresponding to naturally occurring fibroin) is 46.8%.
  • the z / w values of the amino acid sequence shown by SEQ ID NO: 6, the amino acid sequence shown by SEQ ID NO: 7, the amino acid sequence shown by SEQ ID NO: 8, and the amino acid sequence shown by SEQ ID NO: 9 are 58.7%, 70.1%, 66.1% and 70.0%.
  • the value of x / y at the ratio of the amino acid sequences shown in SEQ ID NO: 10, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 and SEQ ID NO: 9 (described later) 1: 1.8 to 11.3 is: 15.0%, 15.0%, 93.4%, 92.7% and 89.3%, respectively.
  • the modified fibroin (2-i) may be composed of the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
  • the modified fibroin (2-ii) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
  • the modified fibroin of (2-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m .
  • the sequence identity is preferably 95% or more.
  • the modified fibroin of (2-ii) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, and is contained in REP (XGX ( Where X is an amino acid residue other than glycine.) Z / w where z is the total number of amino acid residues of the amino acid sequence consisting of z and w is the total number of amino acid residues of REP in the domain sequence. Is preferably 50.9% or more.
  • the second modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal. This makes it possible to isolate, immobilize, detect and visualize the modified fibroin.
  • tag sequences include affinity tags that use specific affinity (binding property, affinity) with other molecules.
  • affinity tag include a histidine tag (His tag).
  • His tag is a short peptide with about 4 to 10 histidine residues, and has the property of binding specifically to metal ions such as nickel. Therefore, the isolation of modified fibroin by metal chelating chromatography (chelating metal chromatography) Can be used.
  • Specific examples of the tag sequence include the amino acid sequence represented by SEQ ID NO: 12 (amino acid sequence including His tag sequence and hinge sequence).
  • GST glutathione-S-transferase
  • MBP maltose-binding protein
  • an “epitope tag” using an antigen-antibody reaction can also be used.
  • a peptide (epitope) exhibiting antigenicity as a tag sequence, an antibody against the epitope can be bound.
  • HA peptide sequence of hemagglutinin of influenza virus
  • myc tag peptide sequence of hemagglutinin of influenza virus
  • FLAG tag peptide sequence of hemagglutinin of influenza virus
  • a tag sequence that can be separated with a specific protease can also be used.
  • the modified fibroin from which the tag sequence has been separated can also be recovered.
  • modified fibroin containing the tag sequence (2-iii) the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, or (2-iv) Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • amino acid sequences represented by SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15 are SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, respectively.
  • an amino acid sequence represented by SEQ ID NO: 12 (including a His tag sequence and a hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 9.
  • the modified fibroin (2-iii) may be composed of the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • the modified fibroin (2-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • the modified fibroin of (2-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m .
  • the sequence identity is preferably 95% or more.
  • the modified fibroin of (2-iv) has an XGX (which has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15 and is contained in REP ( Where X is an amino acid residue other than glycine.) Z / w where z is the total number of amino acid residues of the amino acid sequence consisting of z and w is the total number of amino acid residues of REP in the domain sequence. Is preferably 50.9% or more.
  • the second modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host.
  • the sequence of the secretion signal can be appropriately set according to the type of host.
  • a modified fibroin with a reduced content of n motif is a domain sequence whose amino acid sequence has a reduced content of n motif compared to naturally occurring fibroin (A) Has an array. It can be said that the domain sequence of the third modified fibroin has an amino acid sequence corresponding to the deletion of at least one or more (A) n motifs, as compared to naturally occurring fibroin.
  • the third modified fibroin may have an amino acid sequence corresponding to 10% to 40% deletion of the (A) n motif from naturally occurring fibroin.
  • the third modification fibroin its domain sequence, compared to the naturally occurring fibroin, at least from the N-terminal side toward the C-terminal one to three (A) n motif every one (A) n motif May have an amino acid sequence corresponding to deletion of.
  • the third modified fibroin has a domain sequence that is at least two consecutive from the N-terminal side to the C-terminal side compared to the naturally occurring fibroin (A) deletion of the n motif, and one (A ) It may have an amino acid sequence corresponding to the deletion of the n motif repeated in this order.
  • the third modified fibroin may have an amino acid sequence whose domain sequence corresponds to that at least every two (A) n motifs are deleted from the N-terminal side to the C-terminal side. .
  • the third modified fibroin includes a domain sequence represented by Formula 1: [(A) n motif-REP] m , and two adjacent [(A) n motifs from the N-terminal side toward the C-terminal side. -REP]
  • the ratio of the number of amino acid residues in the other REP is 1.8 to
  • x the maximum total value of the total number of amino acid residues of two adjacent [(A) n motif-REP] units that becomes 11.3
  • x the total number of amino acid residues in the domain sequence is y
  • it may have an amino acid sequence in which x / y is 20% or more, 30% or more, 40% or more, or 50% or more.
  • the number of alanine residues relative to the total number of amino acid residues in the n motif may be 83% or more, preferably 86% or more, more preferably 90% or more, and 95% or more. More preferably, it is 100% (meaning that it is composed only of alanine residues).
  • FIG. 1 shows a domain sequence obtained by removing N-terminal sequence and C-terminal sequence from fibroin.
  • the domain sequence is from the N-terminal side (left side): (A) n motif-first REP (50 amino acid residues)-(A) n motif-second REP (100 amino acid residues)-(A) n Motif-third REP (10 amino acid residues)-(A) n motif-fourth REP (20 amino acid residues)-(A) n motif-fifth REP (30 amino acid residues)-(A) It has a sequence called n motif.
  • FIG. 1 includes pattern 1 (comparison between the first REP and the second REP, and comparison between the third REP and the fourth REP), pattern 2 (comparison between the first REP and the second REP, and 4th REP and 5th REP), pattern 3 (2nd REP and 3rd REP comparison, 4th REP and 5th REP comparison), pattern 4 (first REP and Comparison of the second REP).
  • pattern 1 compare between the first REP and the second REP, and comparison between the third REP and the fourth REP
  • pattern 2 comparison between the first REP and the second REP, and 4th REP and 5th REP
  • pattern 3 (2nd REP and 3rd REP comparison, 4th REP and 5th REP comparison
  • pattern 4 first REP and Comparison of the second REP
  • the number of amino acid residues of each REP in the two adjacent [(A) n motif-REP] units selected is compared.
  • each pattern the number of all amino acid residues of two adjacent [(A) n motif-REP] units indicated by solid lines is added (not only REP but also (A) the number of amino acid residues of the n motif. is there.). Then, the total value added is compared, and the total value (maximum value of the total value) of the pattern having the maximum total value is set as x. In the example shown in FIG. 1, the total value of pattern 1 is the maximum.
  • x / y (%) can be calculated by dividing x by the total number of amino acid residues y of the domain sequence.
  • x / y is preferably 50% or more, more preferably 60% or more, still more preferably 65% or more, and even more preferably 70% or more. Preferably, it is still more preferably 75% or more, and particularly preferably 80% or more. There is no restriction
  • x / y is preferably 89.6% or more, and when the jagged ratio is 1: 1.8 to 3.4, x / y / Y is preferably 77.1% or more, and when the jagged ratio is 1: 1.9 to 8.4, x / y is preferably 75.9% or more, and the jagged ratio is 1 In the case of 1.9 to 4.1, x / y is preferably 64.2% or more.
  • a plurality of third modified fibroins are present in the domain sequence (A)
  • x / y is 46.4% or more It is preferably 50% or more, more preferably 55% or more, still more preferably 60% or more, still more preferably 70% or more, and more preferably 80% or more. It is particularly preferred.
  • one or a plurality of sequences encoding the n motif is deleted so that x / y is 64.2% or more from the cloned gene sequence of naturally occurring fibroin.
  • an amino acid sequence corresponding to the deletion of one or more (A) n motifs is designed so that x / y is 64.2% or more from the amino acid sequence of naturally occurring fibroin. It can also be obtained by chemically synthesizing a nucleic acid encoding the amino acid sequence.
  • one or more amino acid residues are further substituted, deleted, inserted and / or added.
  • the amino acid sequence corresponding to this may be modified.
  • modified fibroin As more specific examples of the third modified fibroin, (3-i) SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, or (3-ii) SEQ ID NO: 18, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 7, SEQ ID No. 8 or SEQ ID No. 9.
  • the modified fibroin (3-i) will be described.
  • the amino acid sequence represented by SEQ ID NO: 18 is the amino acid sequence represented by SEQ ID NO: 10 corresponding to naturally occurring fibroin, wherein (A) n motif is deleted every two from the N-terminal side to the C-terminal side. Furthermore, one [(A) n motif-REP] is inserted in front of the C-terminal sequence.
  • the amino acid sequence shown in SEQ ID NO: 7 is obtained by substituting all GGX in REP of the amino acid sequence shown in SEQ ID NO: 18 with GQX.
  • the amino acid sequence represented by SEQ ID NO: 8 has two alanine residues inserted at the C-terminal side of each (A) n motif of the amino acid sequence represented by SEQ ID NO: 7, and a part of glutamine (Q) residues. Substituted with a serine (S) residue and a part of the amino acid at the N-terminal side was deleted so as to be almost the same as the molecular weight of SEQ ID NO: 7.
  • the amino acid sequence shown in SEQ ID NO: 9 is a region of 20 domain sequences present in the amino acid sequence shown in SEQ ID NO: 11 (however, several amino acid residues on the C-terminal side of the region are substituted). Is a sequence in which a His tag is added to the C-terminal of the sequence repeated four times.
  • the value of x / y in the amino acid sequence represented by SEQ ID NO: 10 (corresponding to naturally-occurring fibroin) at a jagged ratio of 1: 1.8 to 11.3 is 15.0%.
  • the value of x / y in the amino acid sequence shown by SEQ ID NO: 18 and the amino acid sequence shown by SEQ ID NO: 7 are both 93.4%.
  • the value of x / y in the amino acid sequence represented by SEQ ID NO: 8 is 92.7%.
  • the value of x / y in the amino acid sequence represented by SEQ ID NO: 9 is 89.3%.
  • the z / w values in the amino acid sequences represented by SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 and SEQ ID NO: 9 are 46.8%, 56.2%, 70.1% and 66. respectively. 1% and 70.0%.
  • the modified fibroin (3-i) may consist of the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
  • the modified fibroin (3-ii) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
  • the modified fibroin of (3-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m.
  • the sequence identity is preferably 95% or more.
  • the modified fibroin of (3-ii) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, and from the N-terminal side to the C-terminal side
  • the number of amino acid residues of REP of two adjacent [(A) n motif-REP] units is sequentially compared, and the number of amino acid residues of REP having a small number of amino acid residues is 1, the other
  • x / y is 64.2% or more, where x is the maximum total value of the total number of bases and y is the total number of amino acid residues in the domain sequence.
  • the third modified fibroin may contain the tag sequence described above at one or both of the N-terminal and C-terminal.
  • modified fibroin containing the tag sequence (3-iii) SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, or (3-iv) sequence Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • amino acid sequences represented by SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15 are SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, respectively.
  • an amino acid sequence represented by SEQ ID NO: 12 (including a His tag sequence and a hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 9.
  • the modified fibroin may be composed of the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • the modified fibroin (3-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
  • the modified fibroin of (3-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m .
  • the sequence identity is preferably 95% or more.
  • the modified fibroin (3-iv) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, and from the N-terminal side to the C-terminal side.
  • the other X is the maximum total value of the total number of amino acid residues of two adjacent [(A) n motif-REP] units with a ratio of the number of amino acid residues of REP of 1.8 to 11.3.
  • x / y is preferably 64.2% or more.
  • the third modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host.
  • the sequence of the secretion signal can be appropriately set according to the type of host.
  • the content of glycine residues, and (A) n motifs modified fibroin content is reduced in the (fourth modified fibroin), the domain sequence is compared to the naturally occurring fibroin, (A) n motif In addition to having a reduced content of glycine residues, it has an amino acid sequence with a reduced content of glycine residues.
  • the domain sequence of the fourth modified fibroin has at least one or more (A) n motifs deleted as compared to naturally occurring fibroin, and at least one or more glycine residues in the REP. It can be said to have an amino acid sequence corresponding to the substitution with another amino acid residue.
  • the fourth modified fibroin includes the modified fibroin (second modified fibroin) in which the content of the glycine residue described above is reduced, and (A) the modified fibroin (third in which the content of the n motif is reduced). It is a modified fibroin having the characteristics of modified fibroin). Specific embodiments and the like are as described in the second modified fibroin and the third modified fibroin.
  • modified fibroin (4-i) the amino acid sequence represented by SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, (4-ii) SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in FIG.
  • modified fibroin comprising the amino acid sequence represented by SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9 are as described above.
  • a modified fibroin having a domain sequence that locally includes a region having a large hydrophobicity index has a domain sequence of one or more amino acid residues in REP as compared to naturally occurring fibroin.
  • Has a large hydrophobicity index which is equivalent to substitution of an amino acid residue having a large hydrophobicity index and / or insertion of one or more amino acid residues having a large hydrophobicity index into REP. It may have an amino acid sequence including a region.
  • the region where the hydrophobic index is locally large is preferably composed of 2 to 4 amino acid residues.
  • the amino acid residue having a large hydrophobicity index is an amino acid selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A). More preferably, it is a residue.
  • the fifth modified fibroin has one or more amino acid residues in REP substituted with amino acid residues having a higher hydrophobicity index and / or one or more in REP compared to naturally occurring fibroin.
  • substitution, deletion, insertion and / or addition of one or more amino acid residues as compared with naturally occurring fibroin There may be amino acid sequence modifications corresponding to the above.
  • the fifth modified fibroin is obtained by removing one or more hydrophilic amino acid residues (for example, amino acid residues having a negative hydrophobicity index) in the REP from the cloned natural fibroin gene sequence. It can be obtained by substituting a group (for example, an amino acid residue having a positive hydrophobicity index) and / or inserting one or more hydrophobic amino acid residues in REP.
  • hydrophilic amino acid residues for example, amino acid residues having a negative hydrophobicity index
  • a group for example, an amino acid residue having a positive hydrophobicity index
  • one or more hydrophilic amino acid residues in REP are substituted with hydrophobic amino acid residues from the amino acid sequence of naturally occurring fibroin, and / or one or more hydrophobic amino acid residues in REP It can also be obtained by designing an amino acid sequence corresponding to insertion of, and chemically synthesizing a nucleic acid encoding the designed amino acid sequence.
  • one or more hydrophilic amino acid residues in REP have been replaced with hydrophobic amino acid residues from the amino acid sequence of naturally occurring fibroin and / or one or more hydrophobic amino acids in REP
  • the amino acid sequence corresponding to the substitution, deletion, insertion and / or addition of one or more amino acid residues may be further modified.
  • the fifth modified fibroin comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and is located on the most C-terminal side (A) from the n motif to the C terminus of the domain sequence.
  • p is the total number of amino acid residues included in the region where the average value of the hydrophobicity index of four consecutive amino acid residues is 2.6 or more
  • (A) When the total number of amino acid residues contained in the sequence excluding the sequence from the n motif to the C terminus of the domain sequence, which is located at the most C-terminal side, from the domain sequence is q, p / q is 6 It may have an amino acid sequence that is 2% or more.
  • hydrophobicity index of amino acid residues As for the hydrophobicity index of amino acid residues, a known index (Hydropathy index: Kyte J, & Doolittle R (1982) “A simple method for displaying the hydropathic character of bio.p. 7”. 105-132). Specifically, the hydrophobicity index (hydropathic index, hereinafter also referred to as “HI”) of each amino acid is as shown in Table 1 below.
  • a sequence obtained by removing the sequence from the domain sequence represented by Formula 1: [(A) n motif-REP] m to the most C-terminal side from the domain (A) n motif to the C terminus of the domain sequence. (Hereinafter referred to as “array A”).
  • array A the average value of the hydrophobicity index of four consecutive amino acid residues is calculated.
  • the average value of the hydrophobicity index is obtained by dividing the total HI of each amino acid residue contained in the four consecutive amino acid residues by 4 (number of amino acid residues).
  • the average value of the hydrophobicity index is obtained for all four consecutive amino acid residues (each amino acid residue is used for calculating the average value 1 to 4 times). Next, a region where the average value of the hydrophobicity index of four consecutive amino acid residues is 2.6 or more is specified. Even if a certain amino acid residue corresponds to a plurality of “four consecutive amino acid residues whose average value of hydrophobicity index is 2.6 or more”, it should be included as one amino acid residue in the region. become.
  • the total number of amino acid residues contained in the region is p.
  • the total number of amino acid residues contained in sequence A is q.
  • the average value of the hydrophobicity index of four consecutive amino acid residues is 2
  • p / q is preferably 6.2% or more, more preferably 7% or more, further preferably 10% or more, and preferably 20% or more. Even more preferably, it is still more preferably 30% or more.
  • the upper limit of p / q is not particularly limited, but may be 45% or less, for example.
  • the fifth modified fibroin is, for example, one or a plurality of hydrophilic amino acid residues (for example, a hydrophobicity index) in the REP so that the amino acid sequence of the naturally-derived fibroin thus cloned satisfies the above p / q condition. Is replaced with a hydrophobic amino acid residue (for example, an amino acid residue with a positive hydrophobicity index) and / or one or more hydrophobic amino acid residues are inserted in the REP By doing so, it can be obtained by locally modifying the amino acid sequence to include a region having a large hydrophobicity index.
  • hydrophilic amino acid residues for example, a hydrophobicity index
  • an amino acid sequence satisfying the above p / q conditions can be designed from the amino acid sequence of naturally derived fibroin, and a nucleic acid encoding the designed amino acid sequence can be obtained by chemical synthesis.
  • one or more amino acid residues in REP were replaced with amino acid residues having a higher hydrophobicity index and / or one or more amino acid residues in REP.
  • modifications corresponding to substitution, deletion, insertion and / or addition of one or more amino acid residues may be performed. .
  • the amino acid residue having a large hydrophobicity index is not particularly limited, but isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A ) are preferred, and valine (V), leucine (L) and isoleucine (I) are more preferred.
  • modified fibroin As specific examples of the fifth modified fibroin, (5-i) the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21, or (5-ii) SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in FIG.
  • the modified fibroin (5-i) will be described.
  • the amino acid sequence represented by SEQ ID NO: 22 is an amino acid sequence in which alanine residues in the (A) n motif of (A) naturally derived fibroin are deleted so that the number of consecutive alanine residues is five.
  • the amino acid sequence represented by SEQ ID NO: 19 has two amino acid sequences (VLI) each consisting of 3 amino acid residues inserted into every other REP with respect to the amino acid sequence represented by SEQ ID NO: 22, and represented by SEQ ID NO: 22. A part of amino acids on the C-terminal side are deleted so that the molecular weight of the amino acid sequence is almost the same.
  • the amino acid sequence represented by SEQ ID NO: 23 is obtained by inserting two alanine residues to the C-terminal side of each (A) n motif with respect to the amino acid sequence represented by SEQ ID NO: 22, and further adding some glutamine (Q) residues. A group is substituted with a serine (S) residue, and a part of amino acids on the C-terminal side is deleted so as to be approximately the same as the molecular weight of the amino acid sequence represented by SEQ ID NO: 22.
  • the amino acid sequence represented by SEQ ID NO: 20 is obtained by inserting one amino acid sequence (VLI) consisting of 3 amino acid residues every other REP to the amino acid sequence represented by SEQ ID NO: 23.
  • the amino acid sequence shown in SEQ ID NO: 21 is obtained by inserting two amino acid sequences (VLI) each consisting of 3 amino acid residues into the amino acid sequence shown in SEQ ID NO: 23 every other REP.
  • the modified fibroin (5-i) may be composed of the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21.
  • the modified fibroin (5-ii) comprises an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21.
  • the modified fibroin of (5-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m .
  • the sequence identity is preferably 95% or more.
  • the modified fibroin of (5-ii) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21, and is located on the most C-terminal side (A) n
  • the amino acids included in the region where the average value of the hydrophobicity index of 4 consecutive amino acid residues is 2.6 or more P is the total number of residues
  • P / q is preferably 6.2% or more.
  • the fifth modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal.
  • modified fibroin containing a tag sequence (-iii) the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26, or (5-iv) SEQ ID NO: 24, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 25 or SEQ ID No. 26.
  • amino acid sequences represented by SEQ ID NO: 24, SEQ ID NO: 25, and SEQ ID NO: 26 are the amino acid sequences represented by SEQ ID NO: 12 at the N-terminus of the amino acid sequences represented by SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21, respectively (His tag). Including a sequence and a hinge sequence).
  • the modified fibroin may consist of the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26.
  • the modified fibroin (5-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26.
  • the modified fibroin of (5-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m .
  • the sequence identity is preferably 95% or more.
  • the modified fibroin (5-iv) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26, and is located at the most C-terminal side (A) n
  • the amino acids included in the region where the average value of the hydrophobicity index of 4 consecutive amino acid residues is 2.6 or more P is the total number of residues
  • P / q is preferably 6.2% or more.
  • the fifth modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host.
  • the sequence of the secretion signal can be appropriately set according to the type of host.
  • the modified fibroin having a domain sequence in which the content of glutamine residues is reduced (sixth modified fibroin) has an amino acid sequence in which the content of glutamine residues is reduced compared to naturally occurring fibroin.
  • the sixth modified fibroin preferably contains at least one motif selected from GGX motif and GPGXX motif in the amino acid sequence of REP.
  • the content ratio of the GPGXX motif is usually 1% or more, may be 5% or more, and is preferably 10% or more.
  • the upper limit of GPGXX motif content rate 50% or less may be sufficient and 30% or less may be sufficient.
  • the “GPGXX motif content” is a value calculated by the following method.
  • Formula 1 [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m-
  • A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side (A) In all REPs included in the sequence excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence, the total number of GPGXX motifs included in the region is tripled (ie, (Corresponding to the total number of G and P in the GPGXX motif) is defined as s, the sequence from the (A) n motif located at the most C-terminal side to the C-terminus of the domain sequence is excluded from the domain sequence, and (A) the n motif
  • the content ratio of GPGXX motif is calculated as s / t, where t is the total number of amino acid residues of all REPs removed.
  • “A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” (A)
  • the sequence from the n motif to the C terminus of the domain sequence ”(sequence corresponding to REP) may include a sequence that is not highly correlated with the sequence characteristic of fibroin, and m is small In this case (that is, when the domain sequence is short), the calculation result of the content ratio of the GPGXX motif is affected, so this influence is excluded.
  • the “GPGXX motif” is located at the C-terminus of REP, even if “XX” is, for example, “AA”, it is treated as “GPGXX motif”.
  • FIG. 3 is a schematic diagram showing the domain sequence of fibroin.
  • the calculation method of the content ratio of GPGXX motif will be specifically described with reference to FIG.
  • all REPs are “most C-terminally located ( A) GPGXX for calculating s because it is included in the “sequence excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” (the sequence indicated by “region A” in FIG. 3).
  • the sixth modified fibroin preferably has a glutamine residue content of 9% or less, more preferably 7% or less, still more preferably 4% or less, and particularly preferably 0%. .
  • the “glutamine residue content” is a value calculated by the following method.
  • Formula 1 [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side Located in (A) all REPs included in the sequence (sequence corresponding to “region A” in FIG.
  • the total number of glutamine residues is u, the sequence from the (A) n- motif located at the most C-terminal side to the C-terminus of the domain sequence is removed from the domain sequence, and (A) the amino acid residues of all REPs excluding the n- motif
  • the glutamine residue content is calculated as u / t. In the calculation of the glutamine residue content rate, the reason why "A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminus of the domain sequence from the domain sequence" is the reason described above. It is the same.
  • the sixth modified fibroin corresponds to its domain sequence having one or more glutamine residues in REP deleted or replaced with other amino acid residues compared to naturally occurring fibroin. It may have an amino acid sequence.
  • the “other amino acid residue” may be an amino acid residue other than a glutamine residue, but is preferably an amino acid residue having a larger hydrophobicity index than the glutamine residue. Table 1 shows the hydrophobicity index of amino acid residues.
  • amino acid residues having a larger hydrophobicity index than glutamine residues include isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M ) Amino acid residues selected from alanine (A), glycine (G), threonine (T), serine (S), tryptophan (W), tyrosine (Y), proline (P) and histidine (H). it can.
  • an amino acid residue selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A) is more preferable. More preferably, it is an amino acid residue selected from isoleucine (I), valine (V), leucine (L) and phenylalanine (F).
  • the hydrophobicity of REP is preferably ⁇ 0.8 or more, more preferably ⁇ 0.7 or more, still more preferably 0 or more, and 0.3 or more. It is still more preferable that it is and it is especially preferable that it is 0.4 or more.
  • the “hydrophobicity of REP” is a value calculated by the following method.
  • Formula 1 [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side (A) In all REPs included in the sequence (sequence corresponding to “region A” in FIG. 3) obtained by removing the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence (each corresponding to “region A” in FIG.
  • each amino acid in the region Let v be the sum of the hydrophobicity indices of the residues, remove the sequence from the (A) n motif located at the most C-terminal side to the C-terminus of the domain sequence from the domain sequence, and (A) all REPs excluding the n motif
  • the hydrophobicity of REP is calculated as v / t, where t is the total number of amino acid residues.
  • the reason why “A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” is the reason described above. It is the same.
  • the sixth modified fibroin has its domain sequence deleted one or more glutamine residues in REP and / or one or more glutamine residues in REP compared to naturally occurring fibroin.
  • modifications corresponding to substitution of other amino acid residues there may also be amino acid sequence modifications corresponding to substitution, deletion, insertion and / or addition of one or more amino acid residues. .
  • the sixth modified fibroin is, for example, deleting one or more glutamine residues in REP from the cloned gene sequence of naturally occurring fibroin and / or other one or more glutamine residues in REP. It can obtain by substituting to the amino acid residue.
  • one or more glutamine residues in REP are deleted from the amino acid sequence of naturally occurring fibroin, and / or one or more glutamine residues in REP are replaced with other amino acid residues.
  • it can also be obtained by designing a corresponding amino acid sequence and chemically synthesizing a nucleic acid encoding the designed amino acid sequence.
  • the sixth modified fibroin (6-i) the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33
  • (6-ii) the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33 and 90% or more of the sequence Mention may be made of modified fibroin comprising amino acid sequences having identity.
  • the (6-i) modified fibroin will be described.
  • the amino acid sequence shown in SEQ ID NO: 7 is based on the base sequence and amino acid sequence of Nephila clapes (GenBank accession numbers: P46804.1, GI: 1174415), which is a naturally occurring fibroin, based on (A) n
  • the amino acid sequence in which the alanine residue in the motif is continued is modified with an amino acid to improve productivity, such as the number of consecutive alanine residues is five.
  • Met-PRT410 since Met-PRT410 has not altered the glutamine residue (Q), the glutamine residue content is comparable to the glutamine residue content of naturally occurring fibroin.
  • the amino acid sequence (M_PRT888) represented by SEQ ID NO: 27 is obtained by replacing all QQs in Met-PRT410 (SEQ ID NO: 7) with VL.
  • the amino acid sequence represented by SEQ ID NO: 28 (M_PRT965) is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with TS and replacing the remaining Q with A.
  • the amino acid sequence (M_PRT889) shown in SEQ ID NO: 29 is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with VL and replacing the remaining Q with I.
  • the amino acid sequence represented by SEQ ID NO: 30 (M_PRT916) is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with VI and replacing the remaining Q with L.
  • the amino acid sequence (M_PRT918) represented by SEQ ID NO: 31 is obtained by replacing all QQs in Met-PRT410 (SEQ ID NO: 7) with VF and replacing the remaining Q with I.
  • the amino acid sequence represented by SEQ ID NO: 34 is obtained by inserting two alanine residues into a region (A5) where alanine residues are continuous with respect to Met-PRT410 (SEQ ID NO: 7), and the molecular weight of Met-PRT410. Two domain sequences on the C-terminal side were deleted and 13 glutamine residues (Q) were substituted with serine residues (S) or proline residues (P) so that they were almost the same.
  • the amino acid sequence (M_PRT699) represented by SEQ ID NO: 32 is obtained by substituting VL for all QQs in M_PRT525 (SEQ ID NO: 34).
  • the amino acid sequence (M_PRT698) represented by SEQ ID NO: 33 is obtained by substituting all QQs in M_PRT525 (SEQ ID NO: 34) with VL and replacing the remaining Q with I.
  • amino acid sequences represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33 all have a glutamine residue content of 9% or less (Table 2). ).
  • the modified fibroin (6-i) may be composed of the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33. .
  • the modified fibroin of (6-ii) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33
  • the amino acid sequence having The modified fibroin of (6-ii) is also represented by the formula 1: [(A) n motif-REP] m or the formula 2: [(A) n motif-REP] m- (A) n motif.
  • the sequence identity is preferably 95% or more.
  • the modified fibroin (6-ii) preferably has a glutamine residue content of 9% or less.
  • the modified fibroin (6-ii) preferably has a GPGXX motif content of 10% or more.
  • the sixth modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal. This makes it possible to isolate, immobilize, detect and visualize the modified fibroin.
  • modified fibroin containing the tag sequence (6-iii) SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41
  • a modified fibroin comprising the amino acid sequence shown or (6-iv) SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41 and 90 Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of at least%.
  • amino acid sequences represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, and SEQ ID NO: 41 are SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, respectively.
  • the amino acid sequence represented by SEQ ID NO: 12 (including His tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33.
  • the modified fibroin of (6-iii) may be composed of the amino acid sequence represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, or SEQ ID NO: 41. .
  • the modified fibroin of (6-iv) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41.
  • the amino acid sequence having The modified fibroin of (6-iv) is also a domain represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif.
  • the sequence identity is preferably 95% or more.
  • the modified fibroin (6-iv) preferably has a glutamine residue content of 9% or less.
  • the modified fibroin (6-iv) preferably has a GPGXX motif content of 10% or more.
  • the sixth modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host.
  • the sequence of the secretion signal can be appropriately set according to the type of host.
  • the modified fibroin according to the present embodiment is characterized in that the first modified fibroin, the second modified fibroin, the third modified fibroin, the fourth modified fibroin, the fifth modified fibroin, and the sixth modified fibroin Alternatively, it may be a modified fibroin having at least two or more characteristics.
  • a protein derived from collagen for example, a protein comprising a domain sequence represented by Formula 3: [REP2] p (wherein, in Formula 3, p represents an integer of 5 to 300.
  • REP2 represents Gly-XY.
  • X and Y represent any amino acid residue other than Gly.
  • Plural REP2s may be the same amino acid sequence or different amino acid sequences. .
  • Specific examples include a protein containing the amino acid sequence represented by SEQ ID NO: 42.
  • the amino acid sequence shown in SEQ ID NO: 42 corresponds to the repeat portion and motif of the partial sequence of human collagen type 4 (NCBI GenBank accession number: CAA56335.1, GI: 3702452) obtained from the NCBI database.
  • An amino acid sequence represented by SEQ ID NO: 12 (tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence from the 301st residue to the 540th residue.
  • a protein comprising a domain sequence represented by Formula 4: [REP3] q (wherein q represents an integer of 4 to 300.
  • REP3 represents Ser-JJ- An amino acid sequence composed of Tyr-Gly-U-Pro, wherein J represents an arbitrary amino acid residue, and is particularly preferably an amino acid residue selected from the group consisting of Asp, Ser, and Thr.
  • a plurality of REP4 may be the same or different from each other.
  • a protein containing the amino acid sequence represented by SEQ ID NO: 43 can be exemplified.
  • the amino acid sequence represented by SEQ ID NO: 43 is the amino acid sequence of resilin (NCBI GenBank accession number NP 611157, Gl: 24654243), wherein Thr at the 87th residue is replaced with Ser, and the Asn at the 95th residue.
  • the amino acid sequence represented by SEQ ID NO: 12 (tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence from the 19th residue to the 321st residue of the sequence in which is replaced with Asp.
  • Examples of the elastin-derived protein include proteins having amino acid sequences such as NCBI GenBank accession numbers AAC98395 (human), I47076 (sheep), and NP786966 (bovine).
  • a protein containing the amino acid sequence represented by SEQ ID NO: 44 can be exemplified.
  • the amino acid sequence represented by SEQ ID NO: 44 is the amino acid sequence represented by SEQ ID NO: 12 at the N-terminus of the amino acid sequence of residues 121 to 390 of the amino acid sequence of NCBI GenBank accession number AAC98395 (tag sequence). And a hinge arrangement).
  • keratin-derived proteins examples include Capra hircus type I keratin.
  • SEQ ID NO: 45 amino acid sequence of NCBI GenBank accession number ACY30466
  • the above-mentioned structural protein and the modified structural protein derived from the structural protein can be used singly or in combination of two or more.
  • a protein can be expressed, for example, by expressing the nucleic acid in a host transformed with an expression vector having a nucleic acid sequence encoding the protein and one or more regulatory sequences operably linked to the nucleic acid sequence. Can be produced.
  • the method for producing a nucleic acid encoding a protein is not particularly limited.
  • a gene encoding a protein such as natural fibroin is amplified and cloned by polymerase chain reaction (PCR) or the like, and if necessary, modified by genetic engineering techniques, or chemically synthesized
  • the nucleic acid can be produced by the method.
  • the method for chemically synthesizing nucleic acids is not particularly limited.
  • AKTA oligopilot plus 10/100 (GE Healthcare Japan Co., Ltd.) is used based on the amino acid sequence information of proteins obtained from the NCBI web database.
  • a gene can be chemically synthesized by a method of linking oligonucleotides that are synthesized automatically by PCR or the like.
  • nucleic acid encoding a protein consisting of an amino acid sequence in which an amino acid sequence consisting of a start codon and a His10 tag is added to the N terminus of the above amino acid sequence is synthesized. Also good.
  • Regulatory sequences are sequences that control the expression of proteins in the host (for example, promoters, enhancers, ribosome binding sequences, transcription termination sequences, etc.), and can be appropriately selected depending on the type of host.
  • an inducible promoter that functions in a host cell and can induce protein expression may be used.
  • An inducible promoter is a promoter that can control transcription by the presence of an inducer (expression inducer), absence of a repressor molecule, or physical factors such as an increase or decrease in temperature, osmotic pressure or pH value.
  • the type of expression vector can be appropriately selected according to the type of host, such as a plasmid vector, virus vector, cosmid vector, fosmid vector, artificial chromosome vector, and the like.
  • a vector which can replicate autonomously in a host cell or can be integrated into a host chromosome and contains a promoter at a position where a nucleic acid encoding a protein can be transcribed is preferably used.
  • any of prokaryotes and eukaryotes such as yeast, filamentous fungi, insect cells, animal cells and plant cells can be preferably used.
  • prokaryotic hosts include bacteria belonging to the genus Escherichia, Brevibacillus, Serratia, Bacillus, Microbacterium, Brevibacterium, Corynebacterium, Pseudomonas and the like.
  • microorganisms belonging to the genus Escherichia include Escherichia coli.
  • microorganisms belonging to the genus Brevibacillus include Brevibacillus agri and the like.
  • microorganisms belonging to the genus Serratia include Serratia liqufaciens and the like.
  • microorganisms belonging to the genus Bacillus include Bacillus subtilis.
  • microorganisms belonging to the genus Microbacterium include microbacterium / ammonia film.
  • microorganisms belonging to the genus Brevibacterium include Brevibacterium divaricatam.
  • microorganisms belonging to the genus Corynebacterium include Corynebacterium ammoniagenes.
  • microorganisms belonging to the genus Pseudomonas include Pseudomonas putida.
  • examples of a vector for introducing a nucleic acid encoding a protein include pBTrp2 (manufactured by Boehringer Mannheim), pGEX (manufactured by Pharmacia), pUC18, pBluescriptII, pSupex, pET22b, pCold, pUB110, pNCO2 (Japanese Patent Laid-Open No. 2002-238696) and the like.
  • Examples of eukaryotic hosts include yeast and filamentous fungi (molds, etc.).
  • yeast include yeasts belonging to the genus Saccharomyces, Pichia, Schizosaccharomyces and the like.
  • Examples of the filamentous fungi include filamentous fungi belonging to the genus Aspergillus, the genus Penicillium, the genus Trichoderma and the like.
  • examples of a vector into which a nucleic acid encoding a protein is introduced include YEp13 (ATCC37115) and YEp24 (ATCC37051).
  • a method for introducing the expression vector into the host cell any method can be used as long as it is a method for introducing DNA into the host cell.
  • a method using calcium ions [Proc. Natl. Acad. Sci. USA, 69, 2110 (1972)]
  • electroporation method electroporation method
  • spheroplast method protoplast method
  • lithium acetate method competent method, and the like.
  • a method for expressing a nucleic acid by a host transformed with an expression vector in addition to direct expression, secretory production, fusion protein expression, etc. can be performed according to the method described in Molecular Cloning 2nd edition, etc. .
  • the protein can be produced, for example, by culturing a host transformed with an expression vector in a culture medium, producing and accumulating the protein in the culture medium, and collecting the protein from the culture medium.
  • the method for culturing a host in a culture medium can be performed according to a method usually used for culturing a host.
  • the culture medium contains a carbon source, nitrogen source, inorganic salts, etc. that can be assimilated by the host, and can efficiently culture the host. If so, either a natural medium or a synthetic medium may be used.
  • Any carbon source may be used as long as it can be assimilated by the above-mentioned transformed microorganism.
  • Examples thereof include glucose, fructose, sucrose, and carbohydrates such as molasses, starch and starch hydrolyzate, acetic acid and propionic acid, etc.
  • Organic acids and alcohols such as ethanol and propanol can be used.
  • the nitrogen source examples include ammonium salts of inorganic acids or organic acids such as ammonia, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium phosphate, other nitrogen-containing compounds, and peptone, meat extract, yeast extract, corn steep liquor, Casein hydrolyzate, soybean meal and soybean meal hydrolyzate, various fermented cells and digested products thereof can be used.
  • inorganic salts for example, monopotassium phosphate, dipotassium phosphate, magnesium phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate and calcium carbonate can be used.
  • Cultivation of prokaryotes such as E. coli or eukaryotes such as yeast can be performed under aerobic conditions such as shaking culture or deep aeration and agitation culture.
  • the culture temperature is, for example, 15 to 40 ° C.
  • the culture time is usually 16 hours to 7 days.
  • the pH of the culture medium during the culture is preferably maintained at 3.0 to 9.0.
  • the pH of the culture medium can be adjusted using an inorganic acid, an organic acid, an alkaline solution, urea, calcium carbonate, ammonia, or the like.
  • antibiotics such as ampicillin and tetracycline may be added to the culture medium as necessary.
  • an inducer may be added to the medium as necessary.
  • isopropyl- ⁇ -D-thiogalactopyranoside is used when cultivating a microorganism transformed with an expression vector using the lac promoter
  • indole acrylic is used when culturing a microorganism transformed with an expression vector using the trp promoter.
  • An acid or the like may be added to the medium.
  • Isolation and purification of the expressed protein can be performed by a commonly used method.
  • the host cell is recovered by centrifugation after culturing, suspended in an aqueous buffer, and then subjected to an ultrasonic crusher, a French press, a Manton Gaurin.
  • the host cells are disrupted with a homogenizer, dynomill, or the like to obtain a cell-free extract.
  • a method usually used for protein isolation and purification that is, a solvent extraction method, a salting-out method using ammonium sulfate, a desalting method, an organic solvent, etc.
  • Precipitation method anion exchange chromatography method using a resin such as diethylaminoethyl (DEAE) -Sepharose, DIAION HPA-75 (manufactured by Mitsubishi Kasei), and a positive using a resin such as S-Sepharose FF (manufactured by Pharmacia)
  • Electrophoretic methods such as ion exchange chromatography, hydrophobic chromatography using resins such as butyl sepharose and phenyl sepharose, gel filtration using molecular sieve, affinity chromatography, chromatofocusing, isoelectric focusing Using methods such as these alone or in combination, purification It is possible to obtain the goods.
  • the host cell when the protein is expressed by forming an insoluble substance in the cell, the host cell is similarly collected and then crushed and centrifuged to collect the protein insoluble substance as a precipitate fraction.
  • the recovered protein insoluble matter can be solubilized with a protein denaturant.
  • a purified protein preparation can be obtained by the same isolation and purification method as described above.
  • the protein when the protein is secreted extracellularly, the protein can be recovered from the culture supernatant. That is, a culture supernatant is obtained by treating the culture with a technique such as centrifugation, and a purified preparation can be obtained from the culture supernatant by using the same isolation and purification method as described above.
  • the protein composition according to the present embodiment includes at least a modified hydroxyl group-containing polymer and a protein.
  • the modified hydroxyl group-containing polymer and the protein are preferably hydrogen bonded.
  • the hydrogen bond is, for example, a functional group in a modified hydroxyl group-containing polymer (eg, a hydroxyl group, a functional functional group, a functional group in a binding functional group, etc.) and a functional group in a protein (for example, And an amino group, a carboxyl group, etc.).
  • the protein content in the protein composition may be 30 to 99.999% by mass, preferably 35 to 99.99% by mass, and 40 to 99.9% by mass based on the total amount of the protein composition. % Is more preferred.
  • the content of the modified hydroxyl group-containing polymer in the protein composition may be 0.001 to 70% by mass, preferably 0.01 to 65% by mass, based on the total amount of the protein composition. It is more preferably 1 to 60% by mass.
  • the protein composition according to the present embodiment may further contain a hydroxyl group-containing polymer.
  • the hydroxyl group-containing polymer is preferably the same type of polymer as the hydroxyl group-containing polymer that is a raw material for the modified hydroxyl group-containing polymer.
  • the content of the hydroxyl group-containing polymer is 50% by mass or more with respect to 100% by mass of the total amount of the modified hydroxyl group-containing polymer and the hydroxyl group-containing polymer. It may be 60 mass% or more, 70 mass% or more, or 80 mass% or more. Moreover, as an upper limit, it may be 90 mass% or less.
  • the protein composition according to the present embodiment may further contain other additives depending on the form, use, and the like.
  • the additive include a plasticizer, a leveling agent, a crosslinking agent, a crystal nucleating agent, an antioxidant, an ultraviolet absorber, a colorant, a filler, and a synthetic resin.
  • the content of the additive may be 50 parts by mass or less with respect to 100 parts by mass of the total amount of protein.
  • the protein composition according to the present embodiment may be in any form of powder, paste, or liquid (for example, suspension or solution).
  • the protein composition according to the present embodiment includes a protein composition, or a molded body comprising the protein composition (for example, fibers, films, porous bodies, particles, molds). It may be in the form of a molded body).
  • the protein composition according to the present embodiment may be a product containing or consisting of the protein composition.
  • the product include a product selected from the group consisting of fibers, yarns, filaments, films, foams, spheres, nanofibrils, hydrogels, resins, and equivalents. These can be produced according to the methods described in JP-A-2009-505668, JP-A-5678283, JP-A-4638735 and the like.
  • the protein fiber containing or consisting of the protein composition according to the present invention can be applied to woven fabrics, knitted fabrics, braided fabrics, non-woven fabrics and the like as fibers or yarns. It can also be applied to high-strength applications such as ropes, surgical sutures, flexible stops for electrical components, and bioactive materials for transplantation (eg, artificial ligaments and aortic bands).
  • the protein composition according to the present embodiment may be a dope solution.
  • the dope liquid according to this embodiment includes at least a modified hydroxyl group-containing polymer, a protein, and a solvent.
  • the dope liquid according to the present embodiment may further contain a dissolution accelerator.
  • solvent examples include hexafluoroisopropanol (HFIP), hexafluoroacetone (HFA), dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), formic acid, and urea, guanidine, sodium dodecyl sulfate (SDS), Examples include an aqueous solution containing lithium bromide, calcium chloride, lithium thiocyanate, and the like. These solvents may be used alone or in combination of two or more.
  • the protein content in the dope solution may be 15% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more based on the total mass of the dope solution.
  • the content of the protein may be 70% by mass or less, 65% by mass or less, or 60% by mass or less based on the total mass of the dope solution from the viewpoint of the production efficiency of the dope solution.
  • Examples of the dissolution accelerator include inorganic salts composed of the following Lewis acid and Lewis base.
  • Examples of the Lewis base include oxo acid ions (nitrate ions, perchlorate ions, etc.), metal oxo acid ions (permanganate ions, etc.), halide ions, thiocyanate ions, cyanate ions, and the like.
  • Examples of the Lewis acid include metal ions such as alkali metal ions and alkaline earth metal ions, polyatomic ions such as ammonium ions, complex ions, and the like.
  • inorganic salts composed of a Lewis acid and a Lewis base include lithium salts such as lithium chloride, lithium bromide, lithium iodide, lithium nitrate, lithium perchlorate, and lithium thiocyanate, calcium chloride, calcium bromide.
  • Calcium salts such as calcium iodide, calcium nitrate, calcium perchlorate and calcium thiocyanate
  • iron salts such as iron chloride, iron bromide, iron iodide, iron nitrate, iron perchlorate and iron thiocyanate
  • Aluminum salts such as aluminum chloride, aluminum bromide, aluminum iodide, aluminum nitrate, aluminum perchlorate, and aluminum thiocyanate
  • Sodium salts such as sodium uride, sodium nitrate, sodium perchlorate and sodium thiocyanate
  • zinc salts such as zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc perchlorate and zinc thiocyanate
  • chloride Magnesium salts such as magnesium, magnesium bromide, magnesium iodide, magnesium nitrate, magnesium perchlorate, and magnesium thiocyanate, barium chloride, barium bromide, barium iodide, barium nitrate, barium perchlorate, and barium thiocyanate
  • strontium salts such as strontium chloride, strontium bromide, strontium iodide, strontium nitrate, strontium perchlorate, and strontium thiocyanate.
  • Content of a solubility promoter is 1.0 mass part or more, 5.0 mass part or more, 9.0 mass part or more, 15 mass part or more, or 20.0 mass part or more with respect to 100 mass parts of protein whole quantity. It may be.
  • the content of the dissolution promoter may be 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less with respect to 100 parts by mass of the total amount of protein.
  • the method for producing a dope solution according to the present embodiment may include, for example, a step of dissolving a protein and a modified hydroxyl group-containing polymer in a solvent (first production method).
  • the dope liquid according to this embodiment is preferably obtained by the first production method.
  • the step of dissolving the protein and the modified hydroxyl group-containing polymer in the solvent is not limited in the order of dissolving the modified hydroxyl group-containing polymer and the protein in the solvent, and the modified hydroxyl group-containing polymer is dissolved in the solvent.
  • the protein may be dissolved in the solution, the protein may be dissolved in the solvent, and then the modified hydroxyl group-containing polymer may be dissolved in the solution.
  • the protein and the modified hydroxyl group-containing polymer may be dissolved together in the solvent. It may be dissolved.
  • protein after reacting a hydroxyl group-containing polymer and a reactive agent having a functional functional group in a solvent to obtain a modified hydroxyl group-containing polymer, protein may be added to the solution (reaction solution) and dissolved. .
  • the dope solution In the production of the dope solution according to the present embodiment, it may be heated to 30 to 90 ° C. What is necessary is just to set the temperature which can be melt
  • the viscosity of the dope solution according to the present embodiment may be appropriately set according to the use of the dope solution.
  • the viscosity thereof may be appropriately set according to the spinning method, for example, 100 to 15,000 cP (centipoise) at 35 ° C., 100 at 40 ° C. It may be set to ⁇ 30,000 cP (centipoise) or the like.
  • the viscosity of the spinning dope can be measured using, for example, a trade name “EMS viscometer” manufactured by Kyoto Electronics Industry Co., Ltd.
  • the step may be performed in the presence of protein or may be performed in the absence of protein.
  • the step a) is carried out in the absence of protein, the modified hydroxyl group-containing polymer obtained by the reaction and the protein are mixed, and then the step b) may be carried out.
  • the step b) can be carried out after or during the reaction.
  • the step may be performed in a solvent.
  • the step a) can be performed in the same manner as in the above-described method for producing a dope solution.
  • the reaction conditions in the step may be appropriately set according to the type of the reactive agent having a functional functional group and the hydroxyl group-containing polymer to be used.
  • the reaction temperature can be set between 80 to 100 ° C.
  • the reaction time can be set between 2 and 4 hours.
  • the molar concentration ratio of the reactive agent having a functional functional group and the hydroxyl group-containing polymer in the reaction solution is determined based on the modification rate of the modified hydroxyl group-containing polymer (the functional functional group has a ratio to the total number of functional groups capable of reaction).
  • the ratio of the number of bonded functional groups) may be set to a desired value. For example, when the modification rate is desired to be 100%, the molar concentration ratio can be set so that the reactive functional group and the reactive functional group of the hydroxyl group-containing polymer are equimolar.
  • the step is a step of binding the modified hydroxyl group-containing polymer and the protein.
  • the bond between the modified hydroxyl group-containing polymer and the protein may be, for example, a bond caused by entanglement of both polymers, a bond due to an ionic bond, or a bond due to hydrogen bond.
  • the binding between the modified hydroxyl group-containing polymer and the protein can proceed, for example, by dissolving the modified hydroxyl group-containing polymer and protein in a solvent and associating both. It may be bonded spontaneously by dissolving, or may be bonded by concentrating after dissolution, or bonded by releasing the solvent by contacting with a desolvent after dissolution. It may be a thing.
  • step includes b-1) obtaining a dope solution containing a modified hydroxyl group-containing polymer, a protein and a solvent; and b-2) bringing the dope solution into contact with a desolvent and removing the solvent from the dope solution. And a step of hydrogen bonding the protein and the modified hydroxyl group-containing polymer by releasing them.
  • the desolvent may be any solution that can be desolvated, and examples thereof include lower alcohols having 1 to 5 carbon atoms such as methanol, ethanol, and 2-propanol, and acetone.
  • the solvent removal agent may contain water as appropriate.
  • the solvent is removed from the dope solution to hydrogen bond the protein and the modified hydroxyl group-containing polymer, and the protein is solidified to form the protein and the modified hydroxyl group-containing polymer. It may further include obtaining a shaped body to be contained.
  • the shape of the molded body is not particularly limited, and may be, for example, a fiber, a film, a porous body, particles, a molded body, or the like.
  • a molded object can be manufactured by shape
  • the film-like molded body (protein film) is obtained, for example, by a method of forming the above-described dope solution film and removing the solvent from the formed film.
  • the fibrous shaped body (protein fiber) is obtained, for example, by a method of spinning the dope solution described above and removing the solvent from the spun dope solution.
  • a method for producing a porous body from a fibroin-derived protein is described in International Publication No. 2014/175178, and the porous shaped body (protein porous body) is basically obtained by this method.
  • the particle-shaped molded body includes, for example, a step of obtaining an aqueous protein solution by replacing the solvent in the dope solution with a water-soluble solvent, and a step of drying the aqueous protein solution.
  • the water-soluble solvent refers to a solvent containing water, and examples thereof include water, a water-soluble buffer solution, and physiological saline.
  • the step of substituting with a water-soluble solvent is preferably performed by a method in which the dope solution is placed in a dialysis membrane, immersed in the water-soluble solvent, and the water-soluble solvent is replaced one or more times.
  • the dope solution is put into a dialysis membrane and left in a water-soluble solvent (one dose) more than 100 times the dope solution for 3 hours, and this water-soluble solvent exchange is repeated a total of 3 times or more.
  • the dialysis membrane may be any material that does not allow protein permeation, and may be, for example, a cellulose dialysis membrane. By repeating the replacement of the water-soluble solvent, the amount of the solvent present in the dope liquid can be brought close to zero. In the latter half of the step of substituting with a water-soluble solvent, the dialysis membrane may not be used.
  • the step of drying the aqueous protein solution is preferably performed by vacuum freeze drying.
  • the degree of vacuum during vacuum freeze-drying is preferably 200 Pascals (Pa) or less, more preferably 150 Pascals or less, and even more preferably 100 Pascals or less.
  • the moisture content in the particles after freeze-drying is preferably 5.0% or less, more preferably 3.0% or less.
  • a method for producing a molded product from a fibroin-derived protein is described in the specification of International Publication No. 2017/047504, and is basically obtained by this method.
  • the following operation is implemented, for example. That is, first, a composition containing protein (including only protein or other components) is introduced into a mold of a pressure molding machine, and then the mold is heated and pressurized against the composition. Heating and pressurization are continued until the protein reaches a predetermined temperature under a predetermined pressure to obtain a heat-pressed composition.
  • the temperature of the mold is lowered using a cooler (for example, a spot cooler), and when the composition reaches a predetermined temperature, the contents are taken out to obtain a molded body.
  • Heating is preferably performed at 80 to 300 ° C, more preferably 100 to 180 ° C, and still more preferably 100 to 130 ° C.
  • the pressurization is preferably performed at 5 kN or more, more preferably 10 kN or more, and further preferably 20 kN or more.
  • the time for which the treatment is continued under the condition is preferably 0 to 100 minutes, more preferably 1 to 50 minutes, and further preferably 5 to 30 minutes.
  • modified fibroin (1) Preparation of expression vector Based on the nucleotide sequence and amino acid sequence of fibroin (GenBank accession numbers: P46804.1, GI: 1174415) derived from Nephila clavipes, it has the amino acid sequence represented by SEQ ID NO: 15.
  • a modified fibroin also referred to as “PRT799” was designed.
  • the amino acid sequence represented by SEQ ID NO: 15 has an amino acid sequence in which substitution, insertion and deletion of amino acid residues are performed for the purpose of improving productivity with respect to the amino acid sequence of fibroin derived from Nephila clavipes.
  • the amino acid sequence (tag sequence and hinge sequence) represented by SEQ ID NO: 12 is added to the N-terminus.
  • nucleic acid encoding PRT799 was synthesized.
  • the nucleic acid was added with an NdeI site at the 5 'end and an EcoRI site downstream of the stop codon.
  • the nucleic acid was cloned into a cloning vector (pUC118). Thereafter, the nucleic acid was cleaved by restriction enzyme treatment with NdeI and EcoRI, and then recombined with the protein expression vector pET-22b (+) to obtain an expression vector.
  • the seed culture was added to a jar fermenter to which 500 mL of production medium (Table 5) was added so that the OD 600 was 0.05.
  • the culture solution temperature was maintained at 37 ° C., and the culture was performed at a constant pH of 6.9. Further, the dissolved oxygen concentration in the culture solution was maintained at 20% of the dissolved oxygen saturation concentration.
  • a feed solution (glucose 455 g / 1 L, Yeast Extract 120 g / 1 L) was added at a rate of 1 mL / min.
  • the culture solution temperature was maintained at 37 ° C., and the culture was performed at a constant pH of 6.9.
  • the dissolved oxygen concentration in the culture solution was maintained at 20% of the dissolved oxygen saturation concentration, and cultured for 20 hours.
  • 1M isopropyl- ⁇ -thiogalactopyranoside (IPTG) was added to the culture solution to a final concentration of 1 mM to induce expression of the modified fibroin.
  • the culture solution was centrifuged, and the cells were collected. Perform SDS-PAGE using cells prepared from the culture before and after adding IPTG, and confirm the expression of the desired modified fibroin by the appearance of the desired modified fibroin size band depending on the addition of IPTG. did.
  • the washed precipitate was suspended in 8M guanidine buffer (8M guanidine hydrochloride, 10 mM sodium dihydrogen phosphate, 20 mM NaCl, 1 mM Tris-HCl, pH 7.0) to a concentration of 100 mg / mL, and 60 ° C. And stirred for 30 minutes with a stirrer to dissolve. After dissolution, dialysis was performed with water using a dialysis tube (cellulose tube 36/32 manufactured by Sanko Junyaku Co., Ltd.). The white aggregated protein obtained after dialysis was collected by centrifugation, water was removed with a freeze dryer, and the freeze-dried powder was collected to obtain modified fibroin (PRT799).
  • 8M guanidine buffer 8M guanidine hydrochloride, 10 mM sodium dihydrogen phosphate, 20 mM NaCl, 1 mM Tris-HCl, pH 7.0
  • Example 1 Preparation of spinning dope> After 200 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 11400 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), 400 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added thereto. And stirred at 90 ° C. for 4 hours for reaction.
  • DMSO dimethylsulfoxide
  • modified starch modified hydroxyl group-containing polymer in which the phenyl group (functional functional group) was bonded via a urethane bond was obtained.
  • modification rate ratio of hydroxyl groups converted to functional functional groups
  • modified fibroin (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred and dissolved at 90 ° C. for 12 hours to obtain a transparent spinning solution.
  • the content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
  • Example 2 ⁇ Preparation of spinning dope> 253 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), and then 147 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto. The mixture was added and stirred at 90 ° C. for 4 hours for reaction. Thereby, the hydroxyl group of starch reacted with acetic anhydride to obtain a modified starch (modified hydroxyl group-containing polymer) to which an acetyl group (functional functional group) was bonded. In the modified starch, the modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio was 100%.
  • DMSO dimethylsulfoxide
  • modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution.
  • the content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
  • Example 3 ⁇ Preparation of spinning dope> 215 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), and then 185 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto. The mixture was added and stirred at 90 ° C. for 4 hours for reaction. Thereby, the hydroxyl group of starch reacted with acetic anhydride to obtain a modified starch (modified hydroxyl group-containing polymer) to which an acetyl group (functional functional group) was bonded. In the modified starch, the modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio was 50%.
  • DMSO dimethylsulfoxide
  • modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution.
  • the content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
  • Example 4 ⁇ Preparation of spinning dope> After dissolving 128 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved therein. ) 272 mg was added and reacted at 90 ° C. for 4 hours with stirring.
  • PVA polyvinyl alcohol
  • DMSO dimethylsulfoxide
  • the modified PVA had a modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio of 100%.
  • modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution.
  • the content of the modified PVA in the spinning dope is 17% by mass based on the total content of the modified PVA and PVA.
  • Example 5 ⁇ Preparation of spinning dope> After 193 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved therein. ) 207 mg was added and reacted at 90 ° C. with stirring for 4 hours.
  • PVA polyvinyl alcohol
  • DMSO dimethylsulfoxide
  • phenyl isocyanate manufactured by Tokyo Chemical Industry Co., Ltd.
  • the modified PVA had a modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio of 50%.
  • modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution.
  • the content of the modified PVA in the spinning dope is 17% by mass based on the total content of the modified PVA and PVA.
  • Protein fibers using a spinning stock solution containing a modified hydroxyl group-containing polymer modified starch or modified PVA to which a hydrophobic functional group (phenyl group or acetyl group) is bonded as a functional functional group and a protein (modified fibroin)
  • a spinning stock solution containing only protein Comparative Example 1
  • a spinning stock solution containing a protein and an unmodified hydroxyl group-containing polymer Comparison 1 Compared with Example 2
  • the water shrinkage ratio was reduced, and a protein fiber having water resistance was obtained.

Abstract

This invention relates to a protein composition containing a protein and a modified hydroxyl group-containing polymer where a functional group is bonded to a hydroxyl group-containing polymer.

Description

タンパク質組成物及びその製造方法Protein composition and method for producing the same
　本発明は、タンパク質組成物及びその製造方法に関する。 The present invention relates to a protein composition and a method for producing the same.
　近年、環境保全意識の高まりから、石油由来の材料の代替物質の検討が進められており、強度等の点でタンパク質がその候補として挙げられている。タンパク質を用いた成形体として、例えば、特許文献１には、動物繊維の集合体を圧縮成形して得られた、応力－ひずみ特性等の機械的特性が高い動物繊維成形物が開示されている。 In recent years, due to the heightened awareness of environmental conservation, studies are underway on alternative substances for petroleum-derived materials, and proteins are listed as candidates for strength and other factors. As a molded body using protein, for example, Patent Document 1 discloses an animal fiber molded article having high mechanical properties such as stress-strain characteristics obtained by compression molding an animal fiber aggregate. .
特開２０１７－１１０１３２号公報JP 2017-110132 A
　このようなタンパク質成形体等のタンパク質組成物においては、様々な分野への適用にあたって、適用分野等に応じた各種の機能を有することが望まれている。しかしながら、タンパク質を直接化学修飾して機能性を付与する方法は、反応効率が低い等の問題があり、充分な機能性を付与することは困難である。 Such a protein composition such as a protein molded body is desired to have various functions in accordance with application fields and the like when applied to various fields. However, the method of imparting functionality by directly chemically modifying proteins has problems such as low reaction efficiency, and it is difficult to impart sufficient functionality.
　本発明は、機能性が付与されたタンパク質組成物を提供することを目的とする。本発明はまた、タンパク質組成物に効率よく種々の機能性を付与することができるタンパク質組成物の製造方法を提供することを目的とする。 An object of the present invention is to provide a protein composition to which functionality is imparted. Another object of the present invention is to provide a method for producing a protein composition that can efficiently impart various functionalities to the protein composition.
　本発明者らは、タンパク質を直接化学修飾するのではなく、ヒドロキシル基含有ポリマーに機能性官能基が結合した修飾ヒドロキシル基含有ポリマーをタンパク質と混合することにより、タンパク質組成物に機能性官能基による機能性を付与できることを見出した。本発明はこの新規な知見に基づくものである。 The present inventors do not directly chemically modify the protein, but mix the modified hydroxyl group-containing polymer having the functional group bonded to the hydroxyl group-containing polymer with the protein, thereby adding a functional functional group to the protein composition. It was found that functionality can be imparted. The present invention is based on this novel finding.
　本発明は、例えば、以下の各発明を提供する。
［１］
　ヒドロキシル基含有ポリマーに機能性官能基が結合した修飾ヒドロキシル基含有ポリマーと、タンパク質と、を含む、タンパク質組成物。
［２］
　上記修飾ヒドロキシル基含有ポリマーと上記タンパク質が水素結合している、［１］に記載のタンパク質組成物。
［３］
　上記ヒドロキシル基含有ポリマーが多糖類である、［１］又は［２］に記載のタンパク質組成物。
［４］
　上記多糖類がデンプンである、［３］に記載のタンパク質組成物。
［５］
　上記機能性官能基が、フェニル基又はアセチル基である、［１］～［４］のいずれかに記載のタンパク質組成物。
［６］
　上記タンパク質が構造タンパク質である、［１］～［５］のいずれかに記載のタンパク質組成物。
［７］
　上記構造タンパク質がフィブロインである、［６］に記載のタンパク質組成物。
［８］
　上記フィブロインがクモ糸フィブロインである、［７］に記載のタンパク質組成物。
［９］
　上記タンパク質組成物が成形体である、［１］～［８］のいずれかに記載のタンパク質組成物。
［１０］
　上記成形体が繊維である、［９］に記載のタンパク質組成物。
［１１］
　溶媒を更に含み、
　上記タンパク質組成物が、ドープ液である、［１］～［８］のいずれかに記載のタンパク質組成物。
［１２］
　ａ）機能性官能基を有する反応剤とヒドロキシル基含有ポリマーとを反応させて、上記ヒドロキシル基含有ポリマーに上記機能性官能基が結合した修飾ヒドロキシル基含有ポリマーを得る工程と、
　ｂ）上記修飾ヒドロキシル基含有ポリマーとタンパク質とを結合させる工程と、
を備える、タンパク質組成物の製造方法。
［１３］
　上記ｂ）工程が、
　ｂ－１）上記修飾ヒドロキシル基含有ポリマーと上記タンパク質と溶媒とを含むドープ液を得るステップと、
　ｂ－２）上記ドープ液を脱溶媒剤に接触させて、該ドープ液から上記溶媒を離脱させることにより、上記タンパク質と上記修飾ヒドロキシル基含有ポリマーとを水素結合させるステップと、を含む、［１２］に記載のタンパク質組成物の製造方法。
［１４］
　ｂ－２）ステップにおいて、
　上記ドープ液から上記溶媒を離脱させることにより、上記タンパク質と上記修飾ヒドロキシル基含有ポリマーとを水素結合させると共に、上記タンパク質を凝固させて成形し、上記タンパク質と上記修飾ヒドロキシル基含有ポリマーとを含有する成形体を得ることを更に含む、［１３］に記載のタンパク質組成物の製造方法。
［１５］
　上記成形体が繊維である、［１４］に記載のタンパク質組成物の製造方法。
［１６］
　上記ヒドロキシル基含有ポリマーが多糖類である、［１２］～［１５］のいずれかに記載のタンパク質組成物の製造方法。
［１７］
　上記多糖類がデンプンである、［１６］に記載のタンパク質組成物の製造方法。
［１８］
　上記機能性官能基を有する反応剤が、機能性官能基を有するイソシアネートである、［１２］～［１７］のいずれかに記載のタンパク質組成物の製造方法。
［１９］
　上記タンパク質が構造タンパク質である、［１２］～［１８］のいずれかに記載のタンパク質組成物の製造方法。
［２０］
　上記構造タンパク質がフィブロインである、［１９］に記載のタンパク質組成物の製造方法。
［２１］
　上記フィブロインがクモ糸フィブロインである、［２０］に記載のタンパク質組成物の製造方法。 The present invention provides the following inventions, for example.
[1]
A protein composition comprising a modified hydroxyl group-containing polymer having a functional functional group bonded to a hydroxyl group-containing polymer, and a protein.
[2]
The protein composition according to [1], wherein the modified hydroxyl group-containing polymer and the protein are hydrogen bonded.
[3]
The protein composition according to [1] or [2], wherein the hydroxyl group-containing polymer is a polysaccharide.
[4]
The protein composition according to [3], wherein the polysaccharide is starch.
[5]
The protein composition according to any one of [1] to [4], wherein the functional functional group is a phenyl group or an acetyl group.
[6]
The protein composition according to any one of [1] to [5], wherein the protein is a structural protein.
[7]
The protein composition according to [6], wherein the structural protein is fibroin.
[8]
The protein composition according to [7], wherein the fibroin is a spider silk fibroin.
[9]
The protein composition according to any one of [1] to [8], wherein the protein composition is a molded body.
[10]
The protein composition according to [9], wherein the molded body is a fiber.
[11]
Further comprising a solvent,
The protein composition according to any one of [1] to [8], wherein the protein composition is a dope solution.
[12]
a) reacting a reactive agent having a functional functional group with a hydroxyl group-containing polymer to obtain a modified hydroxyl group-containing polymer having the functional functional group bonded to the hydroxyl group-containing polymer;
b) binding the modified hydroxyl group-containing polymer to a protein;
A method for producing a protein composition.
[13]
Step b)
b-1) obtaining a dope solution comprising the modified hydroxyl group-containing polymer, the protein and a solvent;
b-2) bringing the protein into contact with the modified hydroxyl group-containing polymer by bringing the dope solution into contact with a solvent removal agent to release the solvent from the dope solution, [12] ] The manufacturing method of the protein composition as described in.
[14]
In step b-2)
By desorbing the solvent from the dope solution, the protein and the modified hydroxyl group-containing polymer are hydrogen-bonded, and the protein is coagulated and molded to contain the protein and the modified hydroxyl group-containing polymer. The method for producing a protein composition according to [13], further comprising obtaining a molded body.
[15]
The method for producing a protein composition according to [14], wherein the molded body is a fiber.
[16]
The method for producing a protein composition according to any one of [12] to [15], wherein the hydroxyl group-containing polymer is a polysaccharide.
[17]
The method for producing a protein composition according to [16], wherein the polysaccharide is starch.
[18]
The method for producing a protein composition according to any one of [12] to [17], wherein the reactive agent having a functional functional group is an isocyanate having a functional functional group.
[19]
The method for producing a protein composition according to any one of [12] to [18], wherein the protein is a structural protein.
[20]
The method for producing a protein composition according to [19], wherein the structural protein is fibroin.
[21]
The method for producing a protein composition according to [20], wherein the fibroin is a spider silk fibroin.
　本発明によれば、耐水性等の種々の機能性が付与されたタンパク質組成物の提供が可能となる。本発明によればまた、タンパク質組成物に効率よく種々の機能性を付与することができるタンパク質組成物の製造方法の提供が可能となる。 According to the present invention, it is possible to provide a protein composition having various functions such as water resistance. According to the present invention, it is also possible to provide a method for producing a protein composition that can efficiently impart various functionalities to the protein composition.
フィブロインのドメイン配列の一例を示す模式図である。It is a schematic diagram which shows an example of the domain arrangement | sequence of fibroin. フィブロインのドメイン配列の一例を示す模式図である。It is a schematic diagram which shows an example of the domain arrangement | sequence of fibroin. フィブロインのドメイン配列の一例を示す模式図である。It is a schematic diagram which shows an example of the domain arrangement | sequence of fibroin. 製造したタンパク質繊維の水収縮率を評価した結果を示すグラフである。It is a graph which shows the result of having evaluated the water shrinkage rate of the manufactured protein fiber.
　以下、本発明を実施するための形態について詳細に説明する。ただし、本発明は以下の実施形態に限定されるものではない。 Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments.
〔タンパク質組成物〕
　本実施形態に係るタンパク質組成物は、ヒドロキシル基含有ポリマーに機能性官能基が結合した修飾ヒドロキシル基含有ポリマーと、タンパク質と、を含む。 [Protein composition]
The protein composition according to the present embodiment includes a modified hydroxyl group-containing polymer in which a functional functional group is bonded to a hydroxyl group-containing polymer, and a protein.
（修飾ヒドロキシル基含有ポリマー）
　修飾ヒドロキシル基含有ポリマーは、ヒドロキシル基含有ポリマーに機能性官能基が結合したポリマーである。修飾ヒドロキシル基含有ポリマーは、例えば、ヒドロキシル基含有ポリマーと、機能性官能基を有する反応剤とを反応させることで得ることができる。 (Modified hydroxyl group-containing polymer)
The modified hydroxyl group-containing polymer is a polymer in which a functional functional group is bonded to a hydroxyl group-containing polymer. The modified hydroxyl group-containing polymer can be obtained, for example, by reacting a hydroxyl group-containing polymer with a reactive agent having a functional functional group.
　ヒドロキシル基含有ポリマーは、ヒドロキシル基を有する高分子化合物であれば、特に制限なく使用することができる。ヒドロキシル基含有ポリマーの具体例としては、例えば、デンプン、グリコーゲン、セルロース、キチン、アガロース、ヒアルロン酸、コンドロイチン硫酸、ペクチン及びカラギーナン等の多糖類、ポリビニルアルコール（ＰＶＡ）及びフェノール樹脂等の合成高分子が挙げられる。 The hydroxyl group-containing polymer can be used without particular limitation as long as it is a polymer compound having a hydroxyl group. Specific examples of the hydroxyl group-containing polymer include polysaccharides such as starch, glycogen, cellulose, chitin, agarose, hyaluronic acid, chondroitin sulfate, pectin and carrageenan, synthetic polymers such as polyvinyl alcohol (PVA) and phenol resin. Can be mentioned.
　ヒドロキシル基含有ポリマーとしては、生分解性を有するという観点からは、多糖類が好ましい。また、ヒドロキシル基含有ポリマーとしては、生分解性を有することに加え溶解性が高いという観点からは、デンプンが好ましい。 The hydroxyl group-containing polymer is preferably a polysaccharide from the viewpoint of biodegradability. Moreover, as a hydroxyl group containing polymer, starch is preferable from a viewpoint of having high solubility in addition to having biodegradability.
（機能性官能基）
　機能性官能基とは、タンパク質組成物に付与したい機能性（例えば、耐水性、親水性、親油性、耐油性）に対応した特性（例えば、疎水性、親水性）を有する官能基であり、タンパク質組成物に付与したい機能性に応じて、適宜選択することができる。 (Functional functional group)
The functional functional group is a functional group having characteristics (for example, hydrophobicity, hydrophilicity) corresponding to the functionality (for example, water resistance, hydrophilicity, lipophilicity, oil resistance) desired to be imparted to the protein composition, It can select suitably according to the functionality to give to a protein composition.
　例えば、タンパク質組成物の耐水性を向上したい場合は、機能性官能基として、例えば、メチル基、エチル基、ｎ－プロピル基、イソプロピル基等のアルキル基、フェニル基、ナフチル基等の芳香族基、並びにアセチル基、プロパノイル基、ベンゾイル基等のアシル基といった疎水性官能基を使用することができる。 For example, when it is desired to improve the water resistance of the protein composition, examples of functional functional groups include alkyl groups such as methyl, ethyl, n-propyl, and isopropyl groups, and aromatic groups such as phenyl and naphthyl groups. In addition, hydrophobic functional groups such as acyl groups such as acetyl group, propanoyl group, and benzoyl group can be used.
（機能性官能基を有する反応剤）
　機能性官能基を有する反応剤は、機能性官能基を有し、更にヒドロキシル基含有ポリマーと結合可能な結合性官能基を有する化合物である。結合性官能基は、ヒドロキシル基含有ポリマーと、水素結合又は共有結合で結合可能であればよいが、ヒドロキシル基含有ポリマーと共有結合で結合可能な官能基であることが好ましく、ヒドロキシル基含有ポリマー中のヒドロキシル基と共有結合で結合可能な官能基であることがより好ましい。 (Reactive agent having functional functional group)
The reactive agent having a functional functional group is a compound having a functional functional group and further having a binding functional group capable of binding to a hydroxyl group-containing polymer. The binding functional group may be a hydrogen group or a covalent bond capable of binding to the hydroxyl group-containing polymer, but is preferably a functional group capable of covalently binding to the hydroxyl group-containing polymer. It is more preferably a functional group that can be covalently bonded to the hydroxyl group.
　機能性官能基を有する反応剤としては、例えば、機能性官能基を有するイソシアネート（Ｒ－Ｎ＝Ｃ＝Ｏ：Ｒは機能性官能基）、酸無水物（Ｒ－Ｃ（＝Ｏ）－Ｏ－Ｃ（＝Ｏ）－Ｒ：Ｒは機能性官能基）、エポキシド、アジリジン及びアルキルハライド等が挙げられる。機能性官能基を有する反応剤としては、ヒドロキシル基含有ポリマー中のヒドロキシル基と共有結合で結合可能であることから、機能性官能基を有するイソシアネート及び無水酢酸が好ましく、更に任意の機能性官能基を導入可能であることから、機能性官能基を有するイソシアネートがより好ましい。 Examples of the reactive agent having a functional functional group include isocyanate having a functional functional group (RN = C═O: R is a functional functional group), acid anhydride (RC (═O) —O). -C (= O) -R: R is a functional functional group), epoxide, aziridine, alkyl halide and the like. As the reactive agent having a functional functional group, isocyanate and acetic anhydride having a functional functional group are preferable since they can be covalently bonded to the hydroxyl group in the hydroxyl group-containing polymer. Is more preferable since the functional group can be introduced.
（タンパク質）
　タンパク質の種類は特に制限されず、例えば、構造タンパク質であってよい。構造タンパク質とは、生体構造を形成するタンパク質又はそれに由来するタンパク質を示す。すなわち、構造タンパク質は、天然由来の構造タンパク質であってよく、天然由来の構造タンパク質のアミノ酸配列に依拠してそのアミノ酸配列の一部（例えば、当該アミノ酸配列の１０％以下）を改変した改変タンパク質であってもよい。 (protein)
The type of protein is not particularly limited, and may be, for example, a structural protein. The structural protein refers to a protein forming a biological structure or a protein derived therefrom. That is, the structural protein may be a naturally derived structural protein, and a modified protein obtained by modifying a part of the amino acid sequence (for example, 10% or less of the amino acid sequence) based on the amino acid sequence of the naturally derived structural protein. It may be.
　構造タンパク質としては、例えば、フィブロイン、コラ－ゲン、レシリン、エラスチン及びケラチン、並びにこれら由来のタンパク質等を挙げることができる。フィブロインは、例えば、絹フィブロイン、クモ糸フィブロイン、及びホーネットシルクフィブロインからなる群より選択される１種以上であってよい。構造タンパク質は、絹フィブロイン、クモ糸フィブロイン又はこれらの組み合わせであってもよい。絹フィブロインとクモ糸フィブロインとを併用する場合、絹フィブロインの割合は、例えば、クモ糸フィブロイン１００質量部に対して、４０質量部以下、３０質量部以下、又は１０質量部以下であってよい。 Examples of structural proteins include fibroin, collagen, resilin, elastin and keratin, and proteins derived therefrom. The fibroin may be, for example, one or more selected from the group consisting of silk fibroin, spider silk fibroin, and hornet silk fibroin. The structural protein may be silk fibroin, spider silk fibroin or a combination thereof. When silk fibroin and spider silk fibroin are used in combination, the ratio of silk fibroin may be, for example, 40 parts by mass or less, 30 parts by mass or less, or 10 parts by mass or less with respect to 100 parts by mass of spider silk fibroin.
　本実施形態に係るフィブロインは、天然由来のフィブロインと改変フィブロインとを含む。本明細書において「天然由来のフィブロイン」とは、天然由来のフィブロインと同一のアミノ酸配列を有するフィブロインを意味し、「改変フィブロイン」とは、天然由来のフィブロインとは異なるアミノ酸配列を有するフィブロインを意味する。 The fibroin according to the present embodiment includes naturally derived fibroin and modified fibroin. As used herein, “naturally-occurring fibroin” means fibroin having the same amino acid sequence as naturally-occurring fibroin, and “modified fibroin” means fibroin having an amino acid sequence different from that of naturally-occurring fibroin. To do.
　本実施形態に係るフィブロインは、クモ糸フィブロインであることが好ましい。クモ糸フィブロインには、天然クモ糸フィブロイン、及び天然クモ糸フィブロインに由来する改変フィブロインが含まれる。天然クモ糸フィブロインとしては、例えば、クモ類が産生するスパイダーシルクタンパク質が挙げられる。 The fibroin according to the present embodiment is preferably spider silk fibroin. Spider silk fibroin includes natural spider silk fibroin and modified fibroin derived from natural spider silk fibroin. Examples of natural spider silk fibroin include spider silk protein produced by spiders.
　本実施形態に係るフィブロインは、例えば、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むタンパク質であってもよい。本実施形態に係るフィブロインは、ドメイン配列のＮ末端側及びＣ末端側のいずれか一方又は両方に更にアミノ酸配列（Ｎ末端配列及びＣ末端配列）が付加されていてもよい。Ｎ末端配列及びＣ末端配列は、これに限定されるものではないが、典型的には、フィブロインに特徴的なアミノ酸モチーフの反復を有さない領域であり、１００残基程度のアミノ酸からなる。 The fibroin according to the present embodiment is, for example, a domain sequence represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif. It may be a protein containing In the fibroin according to this embodiment, an amino acid sequence (N-terminal sequence and C-terminal sequence) may be further added to either one or both of the N-terminal side and the C-terminal side of the domain sequence. The N-terminal sequence and the C-terminal sequence are not limited to these, but are typically regions having no amino acid motif repeat characteristic of fibroin and consisting of about 100 amino acids.
　本明細書において「ドメイン配列」とは、フィブロイン特有の結晶領域（典型的には、アミノ酸配列の（Ａ）ｎモチーフに相当する。）と非晶領域（典型的には、アミノ酸配列のＲＥＰに相当する。）を生じるアミノ酸配列であり、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるアミノ酸配列を意味する。ここで、（Ａ）ｎモチーフは、アラニン残基を主とするアミノ酸配列を示し、アミノ酸残基数は２～２７である。（Ａ）ｎモチーフのアミノ酸残基数は、２～２０、４～２７、４～２０、８～２０、１０～２０、４～１６、８～１６、又は１０～１６の整数であってよい。また、（Ａ）ｎモチーフ中の全アミノ酸残基数に対するアラニン残基数の割合は４０％以上であればよく、６０％以上、７０％以上、８０％以上、８３％以上、８５％以上、８６％以上、９０％以上、９５％以上、又は１００％（アラニン残基のみで構成されることを意味する。）であってもよい。ドメイン配列中に複数存在する（Ａ）ｎモチーフは、少なくとも７つがアラニン残基のみで構成されてもよい。ＲＥＰは２～２００アミノ酸残基から構成されるアミノ酸配列を示す。ＲＥＰは、１０～２００アミノ酸残基から構成されるアミノ酸配列であってもよい。ｍは２～３００の整数を示し、１０～３００の整数であってもよい。複数存在する（Ａ）ｎモチーフは、互いに同一のアミノ酸配列でもよく、異なるアミノ酸配列でもよい。複数存在するＲＥＰは、互いに同一のアミノ酸配列でもよく、異なるアミノ酸配列でもよい。 In the present specification, the “domain sequence” refers to a fibroin-specific crystal region (typically corresponding to the (A) n motif in the amino acid sequence) and an amorphous region (typically in the REP of the amino acid sequence). Amino acid sequence that gives rise to the following formula: Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) amino acid represented by n motif Means an array. Here, (A) n motif represents an amino acid sequence mainly composed of alanine residues, and the number of amino acid residues is 2 to 27. (A) The number of amino acid residues of the n motif may be an integer of 2 to 20, 4 to 27, 4 to 20, 8 to 20, 10 to 20, 4 to 16, 8 to 16, or 10 to 16 . In addition, the ratio of the number of alanine residues to the total number of amino acid residues in the (A) n motif may be 40% or more, such as 60% or more, 70% or more, 80% or more, 83% or more, 85% or more, It may be 86% or more, 90% or more, 95% or more, or 100% (meaning that it is composed only of alanine residues). A plurality of (A) n motifs present in the domain sequence may be composed of at least seven alanine residues alone. REP indicates an amino acid sequence composed of 2 to 200 amino acid residues. REP may be an amino acid sequence composed of 10 to 200 amino acid residues. m represents an integer of 2 to 300, and may be an integer of 10 to 300. A plurality of (A) n motifs may have the same amino acid sequence or different amino acid sequences. Plural REPs may have the same amino acid sequence or different amino acid sequences.
　天然由来のフィブロインとしては、例えば、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むタンパク質を挙げることができる。天然由来のフィブロインの具体例としては、例えば、昆虫又はクモ類が産生するフィブロインが挙げられる。 Examples of naturally occurring fibroin include a domain sequence represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif. Mention may be made of proteins containing. Specific examples of naturally occurring fibroin include fibroin produced by insects or spiders.
　昆虫が産生するフィブロインとしては、例えば、ボンビックス・モリ（Ｂｏｍｂｙｘ　ｍｏｒｉ）、クワコ（Ｂｏｍｂｙｘ　ｍａｎｄａｒｉｎａ）、天蚕（Ａｎｔｈｅｒａｅａ　ｙａｍａｍａｉ）、柞蚕（Ａｎｔｅｒａｅａ　ｐｅｒｎｙｉ）、楓蚕（Ｅｒｉｏｇｙｎａ　ｐｙｒｅｔｏｒｕｍ）、蓖蚕（Ｐｉｌｏｓａｍｉａ　Ｃｙｎｔｈｉａ　ｒｉｃｉｎｉ）、樗蚕（Ｓａｍｉａ　ｃｙｎｔｈｉａ）、栗虫（Ｃａｌｉｇｕｒａ　ｊａｐｏｎｉｃａ）、チュッサー蚕（Ａｎｔｈｅｒａｅａ　ｍｙｌｉｔｔａ）、ムガ蚕（Ａｎｔｈｅｒａｅａ　ａｓｓａｍａ）等のカイコが産生する絹タンパク質、及びスズメバチ（Ｖｅｓｐａ　ｓｉｍｉｌｌｉｍａ　ｘａｎｔｈｏｐｔｅｒａ）の幼虫が吐出するホーネットシルクタンパク質が挙げられる。 Examples of fibroin produced by insects include, for example, Bombyx mori, Kwako (Bombyx mandarina), Tenaea (Antheraea palaniii), and 楓 蚕 (Eriothyraminey). ), Silkworms produced by silkworms, such as Samia cythia, chestnut worms (Caligula japonica), Chuser moth (Antherea mylitta), Antheraea assama, and vespax (Vespaxia spp.) Hornet silk protein.
　昆虫が産生するフィブロインのより具体的な例としては、例えば、カイコ・フィブロインＬ鎖（ＧｅｎＢａｎｋアクセッション番号Ｍ７６４３０（塩基配列）、及びＡＡＡ２７８４０．１（アミノ酸配列））が挙げられる。 More specific examples of fibroin produced by insects include silkworm fibroin L chain (GenBank accession number M76430 (base sequence) and AAA27840.1 (amino acid sequence)).
　クモ類が産生するフィブロインとしては、例えば、オニグモ、ニワオニグモ、アカオニグモ、アオオニグモ及びマメオニグモ等のオニグモ属（Ａｒａｎｅｕｓ属）に属するクモ、ヤマシロオニグモ、イエオニグモ、ドヨウオニグモ及びサツマノミダマシ等のヒメオニグモ属（Ｎｅｏｓｃｏｎａ属）に属するクモ、コオニグモモドキ等のコオニグモモドキ属（Ｐｒｏｎｕｓ属）に属するクモ、トリノフンダマシ及びオオトリノフンダマシ等のトリノフンダマシ属（Ｃｙｒｔａｒａｃｈｎｅ属）に属するクモ、トゲグモ及びチブサトゲグモ等のトゲグモ属（Ｇａｓｔｅｒａｃａｎｔｈａ属）に属するクモ、マメイタイセキグモ及びムツトゲイセキグモ等のイセキグモ属（Ｏｒｄｇａｒｉｕｓ属）に属するクモ、コガネグモ、コガタコガネグモ及びナガコガネグモ等のコガネグモ属（Ａｒｇｉｏｐｅ属）に属するクモ、キジロオヒキグモ等のオヒキグモ属（Ａｒａｃｈｎｕｒａ属）に属するクモ、ハツリグモ等のハツリグモ属（Ａｃｕｓｉｌａｓ属）に属するクモ、スズミグモ、キヌアミグモ及びハラビロスズミグモ等のスズミグモ属（Ｃｙｔｏｐｈｏｒａ属）に属するクモ、ゲホウグモ等のゲホウグモ属（Ｐｏｌｔｙｓ属）に属するクモ、ゴミグモ、ヨツデゴミグモ、マルゴミグモ及びカラスゴミグモ等のゴミグモ属（Ｃｙｃｌｏｓａ属）に属するクモ、及びヤマトカナエグモ等のカナエグモ属（Ｃｈｏｒｉｚｏｐｅｓ属）に属するクモが産生するスパイダーシルクタンパク質、並びにアシナガグモ、ヤサガタアシナガグモ、ハラビロアシダカグモ及びウロコアシナガグモ等のアシナガグモ属（Ｔｅｔｒａｇｎａｔｈａ属）に属するクモ、オオシロカネグモ、チュウガタシロカネグモ及びコシロカネグモ等のシロカネグモ属（Ｌｅｕｃａｕｇｅ属）に属するクモ、ジョロウグモ及びオオジョロウグモ等のジョロウグモ属（Ｎｅｐｈｉｌａ属）に属するクモ、キンヨウグモ等のアズミグモ属（Ｍｅｎｏｓｉｒａ属）に属するクモ、ヒメアシナガグモ等のヒメアシナガグモ属（Ｄｙｓｃｈｉｒｉｏｇｎａｔｈａ属）に属するクモ、クロゴケグモ、セアカゴケグモ、ハイイロゴケグモ及びジュウサンボシゴケグモ等のゴケグモ属（Ｌａｔｒｏｄｅｃｔｕｓ属）に属するクモ、及びユープロステノプス属（Ｅｕｐｒｏｓｔｈｅｎｏｐｓ属）に属するクモ等のアシナガグモ科（Ｔｅｔｒａｇｎａｔｈｉｄａｅ科）に属するクモが産生するスパイダーシルクタンパク質が挙げられる。スパイダーシルクタンパク質としては、例えば、ＭａＳｐ（ＭａＳｐ１及びＭａＳｐ２）、ＡＤＦ（ＡＤＦ３及びＡＤＦ４）等の牽引糸タンパク質、ＭｉＳｐ（ＭｉＳｐ１及びＭｉＳｐ２）等が挙げられる。 Fibroin produced by spiders includes, for example, spiders belonging to the genus spider (Araneus spp.) Such as the spider spider, the spider spider, the red spider spider, and the bean spider, the genus spiders of the genus Araneus, the spider spider spider, the spider spider genus e Spiders, spiders such as spiders, spiders belonging to the genus Spider, spiders belonging to the genus Pronos, spiders belonging to the genus Trinofunda, such as Torinofundamas (genus Cyrtarachne) Spiders belonging to the genus (Gasteracantha), spiders belonging to the genus Spider (Ordgarius genus), such as the spiders, the spiders, and the spiders belonging to the genus Ordgarius Spiders belonging to the genus Argiope, such as the genus Argiope, spiders belonging to the genus Arachnura, such as the white-tailed spider, spiders belonging to the genus Acusilas such as the common spider, the spider belonging to the genus Acusilas, and the genus Spider Spiders belonging to (genus Cytophora), spiders belonging to the genus Spider belonging to the genus Spider (genus Poltys) such as spiders, genus Spider, spiders belonging to the genus Spider belonging to the genus Cyclosa (genus Cyclosa), and spiders belonging to the genus Cyclosa (genus Cyclosa) Spider silk proteins produced by spiders belonging to the genus Chorizopes), and Asina, such as Asagaaga spider, Yasagata Asaga spider, Harabiro Ashida spider and Urokoa Asaga spider Spiders belonging to the genus Tetragnata, spiders belonging to the genus Spider genus (Leucage genus) such as the white spider spider and the white spider spider, the spider genus belonging to the genus Spider genus (Nephila spp. Spiders belonging to the genus Azumigumi (Menosira), spiders belonging to the genus Dyschiriognatha (genus Dyschiriognatha) such as the common spider spider, the black spider spider, the genus Spider genus belonging to the genus Spider belonging to the genus and the genus Spider belonging to the genus Spider belonging to the genus, and Produced by spiders belonging to the family Tetragnathidae such as spiders belonging to the genus Prostenops Examples include spider silk protein. Examples of the spider silk protein include dragline proteins such as MaSp (MaSp1 and MaSp2) and ADF (ADF3 and ADF4), MiSp (MiSp1 and MiSp2), and the like.
　クモ類が産生するスパイダーシルクタンパク質のより具体的な例としては、例えば、ｆｉｂｒｏｉｎ－３（ａｄｆ－３）［Ａｒａｎｅｕｓ　ｄｉａｄｅｍａｔｕｓ由来］（ＧｅｎＢａｎｋアクセッション番号ＡＡＣ４７０１０（アミノ酸配列）、Ｕ４７８５５（塩基配列））、ｆｉｂｒｏｉｎ－４（ａｄｆ－４）［Ａｒａｎｅｕｓ　ｄｉａｄｅｍａｔｕｓ由来］（ＧｅｎＢａｎｋアクセッション番号ＡＡＣ４７０１１（アミノ酸配列）、Ｕ４７８５６（塩基配列））、ｄｒａｇｌｉｎｅ　ｓｉｌｋ　ｐｒｏｔｅｉｎ　ｓｐｉｄｒｏｉｎ　１［Ｎｅｐｈｉｌａ　ｃｌａｖｉｐｅｓ由来］（ＧｅｎＢａｎｋアクセッション番号ＡＡＣ０４５０４（アミノ酸配列）、Ｕ３７５２０（塩基配列））、ｍａｊｏｒ　ａｍｐｕｌｌａｔｅ　ｓｐｉｄｒｏｉｎ　１［Ｌａｔｒｏｄｅｃｔｕｓ　ｈｅｓｐｅｒｕｓ由来］（ＧｅｎＢａｎｋアクセッション番号ＡＢＲ６８８５６（アミノ酸配列）、ＥＦ５９５２４６（塩基配列））、ｄｒａｇｌｉｎｅ　ｓｉｌｋ　ｐｒｏｔｅｉｎ　ｓｐｉｄｒｏｉｎ　２［Ｎｅｐｈｉｌａ　ｃｌａｖａｔａ由来］（ＧｅｎＢａｎｋアクセッション番号ＡＡＬ３２４７２（アミノ酸配列）、ＡＦ４４１２４５（塩基配列））、ｍａｊｏｒ　ａｍｐｕｌｌａｔｅ　ｓｐｉｄｒｏｉｎ　１［Ｅｕｐｒｏｓｔｈｅｎｏｐｓ　ａｕｓｔｒａｌｉｓ由来］（ＧｅｎＢａｎｋアクセッション番号ＣＡＪ００４２８（アミノ酸配列）、ＡＪ９７３１５５（塩基配列））、及びｍａｊｏｒ　ａｍｐｕｌｌａｔｅ　ｓｐｉｄｒｏｉｎ　２［Ｅｕｐｒｏｓｔｈｅｎｏｐｓ　ａｕｓｔｒａｌｉｓ］（ＧｅｎＢａｎｋアクセッション番号ＣＡＭ３２２４９．１（アミノ酸配列）、ＡＭ４９０１６９（塩基配列））、ｍｉｎｏｒ　ａｍｐｕｌｌａｔｅ　ｓｉｌｋ　ｐｒｏｔｅｉｎ　１［Ｎｅｐｈｉｌａ　ｃｌａｖｉｐｅｓ］（ＧｅｎＢａｎｋアクセッション番号ＡＡＣ１４５８９．１（アミノ酸配列））、ｍｉｎｏｒ　ａｍｐｕｌｌａｔｅ　ｓｉｌｋ　ｐｒｏｔｅｉｎ　２［Ｎｅｐｈｉｌａ　ｃｌａｖｉｐｅｓ］（ＧｅｎＢａｎｋアクセッション番号ＡＡＣ１４５９１．１（アミノ酸配列））、ｍｉｎｏｒ　ａｍｐｕｌｌａｔｅ　ｓｐｉｄｒｏｉｎ－ｌｉｋｅ　ｐｒｏｔｅｉｎ［Ｎｅｐｈｉｌｅｎｇｙｓ　ｃｒｕｅｎｔａｔａ］（ＧｅｎＢａｎｋアクセッション番号ＡＢＲ３７２７８．１（アミノ酸配列）等が挙げられる。 More specific examples of spider silk proteins produced by spiders include, for example, fibroin-3 (adf-3) [derived from Araneus diadematus] (GenBank accession numbers AAC47010 (amino acid sequence), U47855 (base sequence)), fibroin-4 (adf-4) [derived from Araneus diadematus] (GenBank accession number AAC47011 (amino acid sequence), U47856 (base sequence)), dragline silk protein spiroin 1 [derived from Nephila clavipes] (GenBank amino acid sequence 4) ), U37520 (base sequence)), major ampulate spidro n 1 [derived from Latroductus hesperus] (GenBank accession number ABR68856 (amino acid sequence), EF595246 (base sequence)), dragline silk protein spidrin 2 [derived from Nephila clavata (GenBank accession number AAL32 base sequence 45 AAL32 base sequence amino acid 44, amino acid sequence 44 AAL47) )), Major ampulerate spiroin 1 [from Euprosthenops australis] (GenBank accession numbers CAJ00428 (amino acid sequence), AJ973155 (base sequence)), and major amplospiroid 2 [Euprostenaplas ] (GenBank accession number CAM32249.1 (amino acid sequence), AM490169 (base sequence)), minor sample silk protein 1 [Nephila clubs] (GenBank accession number AAC145891 (amino acid sequence)), minor sample 2 [minolampulapple 2] Nephila clavies] (GenBank accession number AAC14591.1 (amino acid sequence)), minor sample spirodin-like protein [Nephilegenes cruentata] (GenBank accession number ABR37278.1 (amino acid sequence), etc.
　天然由来のフィブロインのより具体的な例としては、更に、ＮＣＢＩ　ＧｅｎＢａｎｋに配列情報が登録されているフィブロインを挙げることができる。例えば、ＮＣＢＩ　ＧｅｎＢａｎｋに登録されている配列情報のうちＤＩＶＩＳＩＯＮとしてＩＮＶを含む配列の中から、ＤＥＦＩＮＩＴＩＯＮにｓｐｉｄｒｏｉｎ、ａｍｐｕｌｌａｔｅ、ｆｉｂｒｏｉｎ、「ｓｉｌｋ及びｐｏｌｙｐｅｐｔｉｄｅ」、又は「ｓｉｌｋ及びｐｒｏｔｅｉｎ」がキーワードとして記載されている配列、ＣＤＳから特定のｐｒｏｄｕｃｔの文字列、ＳＯＵＲＣＥからＴＩＳＳＵＥ　ＴＹＰＥに特定の文字列の記載された配列を抽出することにより確認することができる。 More specific examples of naturally derived fibroin include fibroin whose sequence information is registered in NCBI GenBank. For example, spidin, sample, fibroin, “silk and polypeptide”, or “silk and protein” is described as a keyword in DEFINITION from sequences including INV as DIVISION among the sequence information registered in NCBI GenBank. It can be confirmed by extracting a character string of a specific product from the sequence, CDS, and a sequence in which the specific character string is described from SOURCE to TISSUE TYPE.
（改変フィブロイン）
　改変フィブロインは、例えば、天然由来のフィブロインのアミノ酸配列に依拠してそのアミノ酸配列を改変したもの（例えば、クローニングした天然由来のフィブロインの遺伝子配列を改変することによりアミノ酸配列を改変したもの）であってもよく、また天然由来のフィブロインに依らず人工的に設計及び合成したもの（例えば、設計したアミノ酸配列をコードする核酸を化学合成することにより所望のアミノ酸配列を有するもの）であってもよい。 (Modified fibroin)
The modified fibroin is, for example, a modified amino acid sequence based on the amino acid sequence of naturally occurring fibroin (for example, a modified amino acid sequence by modifying the gene sequence of a cloned naturally occurring fibroin). Alternatively, it may be one that is artificially designed and synthesized without relying on natural fibroin (for example, one having a desired amino acid sequence by chemically synthesizing a nucleic acid encoding the designed amino acid sequence). .
　改変フィブロインは、例えば、クローニングした天然由来のフィブロインの遺伝子配列に対し、例えば、１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変を行うことで得ることができる。アミノ酸残基の置換、欠失、挿入及び／又は付加は、部分特異的突然変異誘発法等の当業者に周知の方法により行うことができる。具体的には、Ｎｕｃｌｅｉｃ　Ａｃｉｄ　Ｒｅｓ．１０，６４８７（１９８２）、Ｍｅｔｈｏｄｓ　ｉｎ　Ｅｎｚｙｍｏｌｏｇｙ，１００，４４８（１９８３）等の文献に記載されている方法に準じて行うことができる。 The modified fibroin is, for example, a modification of the amino acid sequence corresponding to, for example, substitution, deletion, insertion and / or addition of one or more amino acid residues to the cloned natural fibroin gene sequence. Can be obtained at Substitution, deletion, insertion and / or addition of amino acid residues can be carried out by methods well known to those skilled in the art such as partial-directed mutagenesis. Specifically, Nucleic Acid Res. 10, 6487 (1982), Methods in Enzymology, 100, 448 (1983), and the like.
　改変フィブロインは、例えば、カイコが産生する絹タンパク質に由来する改変フィブロインであってもよく、クモ類が産生するスパイダーシルクタンパク質に由来する改変フィブロインであってもよい。 The modified fibroin may be, for example, a modified fibroin derived from a silk protein produced by a silkworm, or a modified fibroin derived from a spider silk protein produced by a spider.
　改変フィブロインの具体的な例として、クモの大瓶状腺で産生される大吐糸管しおり糸タンパク質に由来する改変フィブロイン（第１の改変フィブロイン）、グリシン残基の含有量が低減された改変フィブロイン（第２の改変フィブロイン）、（Ａ）ｎモチーフの含有量が低減された改変フィブロイン（第３の改変フィブロイン）、グリシン残基の含有量、及び（Ａ）ｎモチーフの含有量が低減された改変フィブロイン（第４の改変フィブロイン）、局所的に疎水性指標の大きい領域を含むドメイン配列を有する改変フィブロイン（第５の改変フィブロイン）、及びグルタミン残基の含有量が低減されたドメイン配列を有する改変フィブロイン（第６の改変フィブロイン）が挙げられる。 Specific examples of modified fibroin include modified fibroin (first modified fibroin) derived from the large sphincter bookmark silk protein produced in the spider large bottle gland, modified fibroin with reduced glycine residue content (Second modified fibroin), (A) modified fibroin with reduced n- motif content (third modified fibroin), glycine residue content, and (A) n- motif content reduced A modified fibroin (fourth modified fibroin), a modified fibroin having a domain sequence that locally includes a region having a large hydrophobicity index (fifth modified fibroin), and a domain sequence having a reduced glutamine residue content Modified fibroin (sixth modified fibroin) may be mentioned.
　クモの大瓶状腺で産生される大吐糸管しおり糸タンパク質に由来する改変フィブロイン（第１の改変フィブロイン）としては、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質が挙げられる。第１の改変フィブロインは、式１中、ｎは３～２０の整数が好ましく、４～２０の整数がより好ましく、８～２０の整数が更に好ましく、１０～２０の整数が更により好ましく、４～１６の整数が更によりまた好ましく、８～１６の整数が特に好ましく、１０～１６の整数が最も好ましい。第１の改変フィブロインは、式１中、ＲＥＰを構成するアミノ酸残基の数は、１０～２００残基であることが好ましく、１０～１５０残基であることがより好ましく、２０～１００残基であることが更に好ましく、２０～７５残基であることが更により好ましい。第１の改変フィブロインは、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるアミノ酸配列中に含まれるグリシン残基、セリン残基及びアラニン残基の合計残基数がアミノ酸残基数全体に対して、４０％以上であることが好ましく、６０％以上であることがより好ましく、７０％以上であることが更に好ましい。 The modified fibroin derived from the large sphincter bookmark silk protein produced in the spider large bottle-like gland (first modified fibroin) includes a domain sequence represented by Formula 1: [(A) n motif-REP] m The protein containing is mentioned. In the first modified fibroin, in formula 1, n is preferably an integer of 3 to 20, more preferably an integer of 4 to 20, still more preferably an integer of 8 to 20, still more preferably an integer of 10 to 20. An integer of ˜16 is even more preferred, an integer of 8-16 is particularly preferred, and an integer of 10-16 is most preferred. In the first modified fibroin, in Formula 1, the number of amino acid residues constituting REP is preferably 10 to 200 residues, more preferably 10 to 150 residues, and 20 to 100 residues. More preferably, it is more preferably 20 to 75 residues. In the first modified fibroin, the total number of glycine residues, serine residues and alanine residues contained in the amino acid sequence represented by the formula 1: [(A) n motif-REP] m is an amino acid residue. The total number is preferably 40% or more, more preferably 60% or more, and even more preferably 70% or more.
　第１の改変フィブロインは、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるアミノ酸配列の単位を含み、かつＣ末端配列が配列番号１～３のいずれかに示されるアミノ酸配列、又は配列番号１～３のいずれかに示されるアミノ酸配列と９０％以上の相同性を有するアミノ酸配列である、ポリペプチドであってもよい。 The first modified fibroin comprises an amino acid sequence unit represented by Formula 1: [(A) n motif-REP] m , and the C-terminal sequence is represented by any one of SEQ ID NOs: 1 to 3, Alternatively, it may be a polypeptide that is an amino acid sequence having 90% or more homology with the amino acid sequence shown in any one of SEQ ID NOs: 1 to 3.
　配列番号１に示されるアミノ酸配列は、ＡＤＦ３（ＧＩ：１２６３２８７、ＮＣＢＩ）のアミノ酸配列のＣ末端の５０残基のアミノ酸からなるアミノ酸配列と同一であり、配列番号２に示されるアミノ酸配列は、配列番号１に示されるアミノ酸配列のＣ末端から２０残基取り除いたアミノ酸配列と同一であり、配列番号３に示されるアミノ酸配列は、配列番号１に示されるアミノ酸配列のＣ末端から２９残基取り除いたアミノ酸配列と同一である。 The amino acid sequence shown in SEQ ID NO: 1 is identical to the amino acid sequence consisting of 50 amino acids at the C-terminal of the amino acid sequence of ADF3 (GI: 1263287, NCBI), and the amino acid sequence shown in SEQ ID NO: 2 is the sequence The amino acid sequence shown in SEQ ID NO: 1 is identical to the amino acid sequence obtained by removing 20 residues from the C-terminal, and the amino acid sequence shown in SEQ ID NO: 3 has 29 residues removed from the C-terminal of the amino acid sequence shown in SEQ ID NO: 1. It is identical to the amino acid sequence.
　第１の改変フィブロインのより具体的な例として、（１－ｉ）配列番号４で示されるアミノ酸配列、又は（１－ｉｉ）配列番号４で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。配列同一性は、９５％以上であることが好ましい。 As a more specific example of the first modified fibroin, (1-i) the amino acid sequence represented by SEQ ID NO: 4 or (1-ii) the amino acid sequence represented by SEQ ID NO: 4 has a sequence identity of 90% or more. Mention may be made of modified fibroin comprising an amino acid sequence having. The sequence identity is preferably 95% or more.
　配列番号４で示されるアミノ酸配列は、Ｎ末端に開始コドン、Ｈｉｓ１０タグ及びＨＲＶ３Ｃプロテアーゼ（Ｈｕｍａｎ　ｒｈｉｎｏｖｉｒｕｓ　３Ｃプロテアーゼ）認識サイトからなるアミノ酸配列（配列番号５）を付加したＡＤＦ３のアミノ酸配列において、第１～１３番目の反復領域をおよそ２倍になるように増やすとともに、翻訳が第１１５４番目アミノ酸残基で終止するように変異させたものである。配列番号４で示されるアミノ酸配列のＣ末端のアミノ酸配列は、配列番号３で示されるアミノ酸配列と同一である。 The amino acid sequence represented by SEQ ID NO: 4 is an amino acid sequence of ADF3 in which an amino acid sequence (SEQ ID NO: 5) consisting of a start codon, a His10 tag and an HRV3C protease (Human rhinovirus 3C protease) recognition site is added to the N-terminus. The 13th repeat region was increased to approximately double, and the translation was mutated to terminate at the 1154th amino acid residue. The C-terminal amino acid sequence of the amino acid sequence shown in SEQ ID NO: 4 is identical to the amino acid sequence shown in SEQ ID NO: 3.
　（１－ｉ）の改変フィブロインは、配列番号４で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (1-i) may be composed of the amino acid sequence represented by SEQ ID NO: 4.
　グリシン残基の含有量が低減された改変フィブロイン（第２の改変フィブロイン）は、そのドメイン配列が、天然由来のフィブロインと比較して、グリシン残基の含有量が低減されたアミノ酸配列を有する。第２の改変フィブロインは、天然由来のフィブロインと比較して、少なくともＲＥＰ中の１又は複数のグリシン残基が別のアミノ酸残基に置換されたことに相当するアミノ酸配列を有するものということができる。 The modified fibroin with a reduced content of glycine residues (second modified fibroin) has an amino acid sequence with a reduced content of glycine residues in the domain sequence compared to naturally occurring fibroin. It can be said that the second modified fibroin has an amino acid sequence corresponding to at least one or more glycine residues in REP substituted with another amino acid residue as compared with naturally occurring fibroin. .
　第２の改変フィブロインは、そのドメイン配列が、天然由来のフィブロインと比較して、ＲＥＰ中のＧＧＸ及びＧＰＧＸＸ（但し、Ｇはグリシン残基、Ｐはプロリン残基、Ｘはグリシン以外のアミノ酸残基を示す。）から選ばれる少なくとも一つのモチーフ配列において、少なくとも１又は複数の当該モチーフ配列中の１つのグリシン残基が別のアミノ酸残基に置換されたことに相当するアミノ酸配列を有するものであってもよい。 The second modified fibroin has a domain sequence of GGX and GPGXX in REP (where G is a glycine residue, P is a proline residue, and X is an amino acid residue other than glycine) as compared to naturally occurring fibroin. In which at least one glycine residue in at least one or more of the motif sequences is substituted with another amino acid residue. May be.
　第２の改変フィブロインは、上述のグリシン残基が別のアミノ酸残基に置換されたモチーフ配列の割合が、全モチーフ配列に対して、１０％以上であってもよい。 In the second modified fibroin, the ratio of the motif sequence in which the above glycine residue is replaced with another amino acid residue may be 10% or more with respect to the entire motif sequence.
　第２の改変フィブロインは、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含み、上記ドメイン配列から、最もＣ末端側に位置する（Ａ）ｎモチーフから上記ドメイン配列のＣ末端までの配列を除いた配列中の全ＲＥＰに含まれるＸＧＸ（但し、Ｘはグリシン以外のアミノ酸残基を示す。）からなるアミノ酸配列の総アミノ酸残基数をｚとし、上記ドメイン配列から、最もＣ末端側に位置する（Ａ）ｎモチーフから上記ドメイン配列のＣ末端までの配列を除いた配列中の総アミノ酸残基数をｗとしたときに、ｚ／ｗが３０％以上、４０％以上、５０％以上又は５０．９％以上であるアミノ酸配列を有するものであってもよい。（Ａ）ｎモチーフ中の全アミノ酸残基数に対するアラニン残基数は８３％以上であってよいが、８６％以上であることが好ましく、９０％以上であることがより好ましく、９５％以上であることが更に好ましく、１００％であること（アラニン残基のみで構成されることを意味する）が更により好ましい。 The second modified fibroin comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and is located on the most C-terminal side from the domain sequence (A) from the n motif to the domain sequence. The total number of amino acid residues in the amino acid sequence consisting of XGX (where X represents an amino acid residue other than glycine) contained in all REPs in the sequence excluding the sequence up to the C-terminal of (A) where the total number of amino acid residues in the sequence excluding the sequence from the n motif located at the most C-terminal side to the C-terminal of the domain sequence is w, z / w is 30% or more, It may have an amino acid sequence that is 40% or more, 50% or more, or 50.9% or more. (A) The number of alanine residues relative to the total number of amino acid residues in the n motif may be 83% or more, preferably 86% or more, more preferably 90% or more, and 95% or more. More preferably, it is 100% (meaning that it is composed only of alanine residues).
　第２の改変フィブロインは、ＧＧＸモチーフの１つのグリシン残基を別のアミノ酸残基に置換することにより、ＸＧＸからなるアミノ酸配列の含有割合を高めたものであることが好ましい。第２の改変フィブロインは、ドメイン配列中のＧＧＸからなるアミノ酸配列の含有割合が３０％以下であることが好ましく、２０％以下であることがより好ましく、１０％以下であることが更に好ましく、６％以下であることが更により好ましく、４％以下であることが更によりまた好ましく、２％以下であることが特に好ましい。ドメイン配列中のＧＧＸからなるアミノ酸配列の含有割合は、下記ＸＧＸからなるアミノ酸配列の含有割合（ｚ／ｗ）の算出方法と同様の方法で算出することができる。 The second modified fibroin is preferably one in which the content ratio of the amino acid sequence consisting of XGX is increased by substituting one glycine residue of the GGX motif with another amino acid residue. In the second modified fibroin, the content ratio of the amino acid sequence consisting of GGX in the domain sequence is preferably 30% or less, more preferably 20% or less, still more preferably 10% or less, % Or less is even more preferable, 4% or less is even more preferable, and 2% or less is particularly preferable. The content ratio of the amino acid sequence consisting of GGX in the domain sequence can be calculated by the same method as the method for calculating the content ratio (z / w) of the amino acid sequence consisting of XGX below.
　ｚ／ｗの算出方法を更に詳細に説明する。まず、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むフィブロイン（改変フィブロイン又は天然由来のフィブロイン）において、ドメイン配列から、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列を除いた配列に含まれる全てのＲＥＰから、ＸＧＸからなるアミノ酸配列を抽出する。ＸＧＸを構成するアミノ酸残基の総数がｚである。例えば、ＸＧＸからなるアミノ酸配列が５０個抽出された場合（重複はなし）、ｚは５０×３＝１５０である。また、例えば、ＸＧＸＧＸからなるアミノ酸配列の場合のように２つのＸＧＸに含まれるＸ（中央のＸ）が存在する場合は、重複分を控除して計算する（ＸＧＸＧＸの場合は５アミノ酸残基である）。ｗは、ドメイン配列から、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列を除いた配列に含まれる総アミノ酸残基数である。例えば、図１に示したドメイン配列の場合、ｗは４＋５０＋４＋１００＋４＋１０＋４＋２０＋４＋３０＝２３０である（最もＣ末端側に位置する（Ａ）ｎモチーフは除いている。）。次に、ｚをｗで除すことによって、ｚ／ｗ（％）を算出することができる。 The method for calculating z / w will be described in more detail. First, in a fibroin (modified fibroin or naturally-occurring fibroin) containing a domain sequence represented by Formula 1: [(A) n motif-REP] m , (A) n located closest to the C-terminal side from the domain sequence An amino acid sequence consisting of XGX is extracted from all REPs included in the sequence excluding the sequence from the motif to the C-terminal of the domain sequence. The total number of amino acid residues constituting XGX is z. For example, when 50 amino acid sequences consisting of XGX are extracted (no duplication), z is 50 × 3 = 150. Also, for example, when there is an X (center X) included in two XGXs as in the case of an amino acid sequence consisting of XGXGX, the calculation is performed by subtracting the overlap (in the case of XGXGX, it is 5 amino acid residues). is there). w is the total number of amino acid residues contained in the sequence excluding the sequence from the domain sequence to the most C-terminal (A) n motif to the C-terminus of the domain sequence. For example, in the case of the domain sequence shown in FIG. 1, w is 4 + 50 + 4 + 100 + 4 + 10 + 4 + 20 + 4 + 30 = 230 (excluding the (A) n motif located closest to the C-terminal side). Next, z / w (%) can be calculated by dividing z by w.
　第２の改変フィブロインにおいて、ｚ／ｗは、５０．９％以上であることが好ましく、５６．１％以上であることがより好ましく、５８．７％以上であることが更に好ましく、７０％以上であることが更により好ましく、８０％以上であることが更によりまた好ましい。ｚ／ｗの上限に特に制限はないが、例えば、９５％以下であってもよい。 In the second modified fibroin, z / w is preferably 50.9% or more, more preferably 56.1% or more, further preferably 58.7% or more, and 70% or more. It is still more preferable that it is 80% or more. Although there is no restriction | limiting in particular in the upper limit of z / w, For example, 95% or less may be sufficient.
　第２の改変フィブロインは、例えば、クローニングした天然由来のフィブロインの遺伝子配列から、グリシン残基をコードする塩基配列の少なくとも一部を置換して別のアミノ酸残基をコードするように改変することにより得ることができる。このとき、改変するグリシン残基として、ＧＧＸモチーフ及びＧＰＧＸＸモチーフにおける１つのグリシン残基を選択してもよいし、またｚ／ｗが５０．９％以上になるように置換してもよい。また、例えば、天然由来のフィブロインのアミノ酸配列から上記態様を満たすアミノ酸配列を設計し、設計したアミノ酸配列をコードする核酸を化学合成することにより得ることもできる。いずれの場合においても、天然由来のフィブロインのアミノ酸配列からＲＥＰ中のグリシン残基を別のアミノ酸残基に置換したことに相当する改変に加え、更に１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変を行ってもよい。 The second modified fibroin is obtained by, for example, modifying a cloned natural fibroin gene sequence so as to encode another amino acid residue by substituting at least a part of a base sequence encoding a glycine residue. Obtainable. At this time, one glycine residue in GGX motif and GPGXX motif may be selected as a glycine residue to be modified, or substitution may be performed so that z / w is 50.9% or more. In addition, for example, an amino acid sequence satisfying the above-described aspect can be designed from the amino acid sequence of naturally derived fibroin, and a nucleic acid encoding the designed amino acid sequence can be obtained by chemical synthesis. In any case, in addition to the modification corresponding to the substitution of the glycine residue in REP with another amino acid residue from the amino acid sequence of naturally occurring fibroin, one or more amino acid residues are further substituted or deleted. The amino acid sequence corresponding to the insertion and / or addition may be modified.
　上記の別のアミノ酸残基としては、グリシン残基以外のアミノ酸残基であれば特に制限はないが、バリン（Ｖ）残基、ロイシン（Ｌ）残基、イソロイシン（Ｉ）残基、メチオニン（Ｍ）残基、プロリン（Ｐ）残基、フェニルアラニン（Ｆ）残基及びトリプトファン（Ｗ）残基等の疎水性アミノ酸残基、グルタミン（Ｑ）残基、アスパラギン（Ｎ）残基、セリン（Ｓ）残基、リシン（Ｋ）残基及びグルタミン酸（Ｅ）残基等の親水性アミノ酸残基が好ましく、バリン（Ｖ）残基、ロイシン（Ｌ）残基、イソロイシン（Ｉ）残基及びグルタミン（Ｑ）残基がより好ましく、グルタミン（Ｑ）残基が更に好ましい。 The other amino acid residue is not particularly limited as long as it is an amino acid residue other than glycine residue, but valine (V) residue, leucine (L) residue, isoleucine (I) residue, methionine ( M) hydrophobic amino acid residues such as proline (P) residue, phenylalanine (F) residue and tryptophan (W) residue, glutamine (Q) residue, asparagine (N) residue, serine (S ) Residues, lysine (K) residues and glutamic acid (E) residues are preferred, and valine (V) residues, leucine (L) residues, isoleucine (I) residues and glutamine ( Q) residue is more preferable, and glutamine (Q) residue is more preferable.
　第２の改変フィブロインのより具体的な例として、（２－ｉ）配列番号６、配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列、又は（２－ｉｉ）配列番号６、配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As a more specific example of the second modified fibroin, (2-i) the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, or (2-ii) SEQ ID NO: 6, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 7, SEQ ID No. 8 or SEQ ID No. 9.
　（２－ｉ）の改変フィブロインについて説明する。配列番号６で示されるアミノ酸配列は、天然由来のフィブロインに相当する配列番号１０で示されるアミノ酸配列のＲＥＰ中の全てのＧＧＸをＧＱＸに置換したものである。配列番号７で示されるアミノ酸配列は、配列番号６で示されるアミノ酸配列から、Ｎ末端側からＣ末端側に向かって２つおきに（Ａ）ｎモチーフを欠失させ、更にＣ末端配列の手前に［（Ａ）ｎモチーフ－ＲＥＰ］を１つ挿入したものである。配列番号８で示されるアミノ酸配列は、配列番号７で示されるアミノ酸配列の各（Ａ）ｎモチーフのＣ末端側に２つのアラニン残基を挿入し、更に一部のグルタミン（Ｑ）残基をセリン（Ｓ）残基に置換し、配列番号７の分子量とほぼ同じとなるようにＮ末端側の一部のアミノ酸を欠失させたものである。配列番号９で示されるアミノ酸配列は、配列番号１１で示されるアミノ酸配列中に存在する２０個のドメイン配列の領域（但し、当該領域のＣ末端側の数アミノ酸残基が置換されている。）を４回繰り返した配列のＣ末端にＨｉｓタグが付加されたものである。 The modified fibroin (2-i) will be described. The amino acid sequence represented by SEQ ID NO: 6 is obtained by substituting all GGX in REP of the amino acid sequence represented by SEQ ID NO: 10 corresponding to naturally occurring fibroin with GQX. The amino acid sequence represented by SEQ ID NO: 7 is the amino acid sequence represented by SEQ ID NO: 6, wherein every two (A) n motifs are deleted from the N-terminal side to the C-terminal side, and further before the C-terminal sequence. One [(A) n motif-REP] is inserted into the. The amino acid sequence represented by SEQ ID NO: 8 has two alanine residues inserted at the C-terminal side of each (A) n motif of the amino acid sequence represented by SEQ ID NO: 7, and a part of glutamine (Q) residues. Substituted with a serine (S) residue and a part of the amino acid at the N-terminal side was deleted so as to be almost the same as the molecular weight of SEQ ID NO: 7. The amino acid sequence shown in SEQ ID NO: 9 is a region of 20 domain sequences present in the amino acid sequence shown in SEQ ID NO: 11 (however, several amino acid residues on the C-terminal side of the region are substituted). Is a sequence in which a His tag is added to the C-terminal of the sequence repeated four times.
　配列番号１０で示されるアミノ酸配列（天然由来のフィブロインに相当）におけるｚ／ｗの値は、４６．８％である。配列番号６で示されるアミノ酸配列、配列番号７で示されるアミノ酸配列、配列番号８で示されるアミノ酸配列、及び配列番号９で示されるアミノ酸配列におけるｚ／ｗの値は、それぞれ５８．７％、７０．１％、６６．１％及び７０．０％である。また、配列番号１０、配列番号６、配列番号７、配列番号８及び配列番号９で示されるアミノ酸配列のギザ比率（後述する）１：１．８～１１．３におけるｘ／ｙの値は、それぞれ１５．０％、１５．０％、９３．４％、９２．７％及び８９．３％である。 The value of z / w in the amino acid sequence represented by SEQ ID NO: 10 (corresponding to naturally occurring fibroin) is 46.8%. The z / w values of the amino acid sequence shown by SEQ ID NO: 6, the amino acid sequence shown by SEQ ID NO: 7, the amino acid sequence shown by SEQ ID NO: 8, and the amino acid sequence shown by SEQ ID NO: 9 are 58.7%, 70.1%, 66.1% and 70.0%. In addition, the value of x / y at the ratio of the amino acid sequences shown in SEQ ID NO: 10, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 and SEQ ID NO: 9 (described later) 1: 1.8 to 11.3 is: 15.0%, 15.0%, 93.4%, 92.7% and 89.3%, respectively.
　（２－ｉ）の改変フィブロインは、配列番号６、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (2-i) may be composed of the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
　（２－ｉｉ）の改変フィブロインは、配列番号６、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（２－ｉｉ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (2-ii) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9. The modified fibroin of (2-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m . The sequence identity is preferably 95% or more.
　（２－ｉｉ）の改変フィブロインは、配列番号６、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつＲＥＰ中に含まれるＸＧＸ（但し、Ｘはグリシン以外のアミノ酸残基を示す。）からなるアミノ酸配列の総アミノ酸残基数をｚとし、上記ドメイン配列中のＲＥＰの総アミノ酸残基数をｗとしたときに、ｚ／ｗが５０．９％以上であることが好ましい。 The modified fibroin of (2-ii) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, and is contained in REP (XGX ( Where X is an amino acid residue other than glycine.) Z / w where z is the total number of amino acid residues of the amino acid sequence consisting of z and w is the total number of amino acid residues of REP in the domain sequence. Is preferably 50.9% or more.
　第２の改変フィブロインは、Ｎ末端及びＣ末端のいずれか一方又は両方にタグ配列を含んでいてもよい。これにより、改変フィブロインの単離、固定化、検出及び可視化等が可能となる。 The second modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal. This makes it possible to isolate, immobilize, detect and visualize the modified fibroin.
　タグ配列として、例えば、他の分子との特異的親和性（結合性、アフィニティ）を利用したアフィニティタグを挙げることができる。アフィニティタグの具体例として、ヒスチジンタグ（Ｈｉｓタグ）を挙げることができる。Ｈｉｓタグは、ヒスチジン残基が４から１０個程度並んだ短いペプチドで、ニッケル等の金属イオンと特異的に結合する性質があるため、金属キレートクロマトグラフィー（ｃｈｅｌａｔｉｎｇ　ｍｅｔａｌ　ｃｈｒｏｍａｔｏｇｒａｐｈｙ）による改変フィブロインの単離に利用することができる。タグ配列の具体例として、例えば、配列番号１２で示されるアミノ酸配列（Ｈｉｓタグ配列及びヒンジ配列を含むアミノ酸配列）が挙げられる。 Examples of tag sequences include affinity tags that use specific affinity (binding property, affinity) with other molecules. Specific examples of the affinity tag include a histidine tag (His tag). The His tag is a short peptide with about 4 to 10 histidine residues, and has the property of binding specifically to metal ions such as nickel. Therefore, the isolation of modified fibroin by metal chelating chromatography (chelating metal chromatography) Can be used. Specific examples of the tag sequence include the amino acid sequence represented by SEQ ID NO: 12 (amino acid sequence including His tag sequence and hinge sequence).
　また、グルタチオンに特異的に結合するグルタチオン－Ｓ－トランスフェラーゼ（ＧＳＴ）、マルトースに特異的に結合するマルトース結合タンパク質（ＭＢＰ）等のタグ配列を利用することもできる。 Tag sequences such as glutathione-S-transferase (GST) that specifically binds to glutathione and maltose-binding protein (MBP) that specifically binds to maltose can also be used.
　さらに、抗原抗体反応を利用した「エピトープタグ」を利用することもできる。抗原性を示すペプチド（エピトープ）をタグ配列として付加することにより、当該エピトープに対する抗体を結合させることができる。エピトープタグとして、ＨＡ（インフルエンザウイルスのヘマグルチニンのペプチド配列）タグ、ｍｙｃタグ、ＦＬＡＧタグ等を挙げることができる。エピトープタグを利用することにより、高い特異性で容易に改変フィブロインを精製することができる。 Furthermore, an “epitope tag” using an antigen-antibody reaction can also be used. By adding a peptide (epitope) exhibiting antigenicity as a tag sequence, an antibody against the epitope can be bound. As the epitope tag, HA (peptide sequence of hemagglutinin of influenza virus) tag, myc tag, FLAG tag and the like can be mentioned. By using the epitope tag, the modified fibroin can be easily purified with high specificity.
　さらにタグ配列を特定のプロテアーゼで切り離せるようにしたものも使用することができる。当該タグ配列を介して吸着したタンパク質をプロテアーゼ処理することにより、タグ配列を切り離した改変フィブロインを回収することもできる。 Furthermore, a tag sequence that can be separated with a specific protease can also be used. By treating the protein adsorbed via the tag sequence with protease, the modified fibroin from which the tag sequence has been separated can also be recovered.
　タグ配列を含む第２の改変フィブロインのより具体的な例として、（２－ｉｉｉ）配列番号１３、配列番号１１、配列番号１４若しく配列番号１５で示されるアミノ酸配列、又は（２－ｉｖ）配列番号１３、配列番号１１、配列番号１４若しく配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As a more specific example of the second modified fibroin containing the tag sequence, (2-iii) the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, or (2-iv) Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
　配列番号１６、配列番号１７、配列番号１３、配列番号１１、配列番号１４及び配列番号１５で示されるアミノ酸配列は、それぞれ配列番号１０、配列番号１８、配列番号６、配列番号７、配列番号８及び配列番号９で示されるアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（Ｈｉｓタグ配列及びヒンジ配列を含む）を付加したものである。 The amino acid sequences represented by SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15 are SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, respectively. And an amino acid sequence represented by SEQ ID NO: 12 (including a His tag sequence and a hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 9.
　（２－ｉｉｉ）の改変フィブロインは、配列番号１３、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (2-iii) may be composed of the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
　（２－ｉｖ）の改変フィブロインは、配列番号１３、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（２－ｉｖ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (2-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15. The modified fibroin of (2-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m . The sequence identity is preferably 95% or more.
　（２－ｉｖ）の改変フィブロインは、配列番号１３、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつＲＥＰ中に含まれるＸＧＸ（但し、Ｘはグリシン以外のアミノ酸残基を示す。）からなるアミノ酸配列の総アミノ酸残基数をｚとし、上記ドメイン配列中のＲＥＰの総アミノ酸残基数をｗとしたときに、ｚ／ｗが５０．９％以上であることが好ましい。 The modified fibroin of (2-iv) has an XGX (which has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15 and is contained in REP ( Where X is an amino acid residue other than glycine.) Z / w where z is the total number of amino acid residues of the amino acid sequence consisting of z and w is the total number of amino acid residues of REP in the domain sequence. Is preferably 50.9% or more.
　第２の改変フィブロインは、組換えタンパク質生産系において生産されたタンパク質を宿主の外部に放出するための分泌シグナルを含んでいてもよい。分泌シグナルの配列は、宿主の種類に応じて適宜設定することができる。 The second modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host. The sequence of the secretion signal can be appropriately set according to the type of host.
　（Ａ）ｎモチーフの含有量が低減された改変フィブロイン（第３の改変フィブロイン）は、そのドメイン配列が、天然由来のフィブロインと比較して、（Ａ）ｎモチーフの含有量が低減されたアミノ酸配列を有する。第３の改変フィブロインのドメイン配列は、天然由来のフィブロインと比較して、少なくとも１又は複数の（Ａ）ｎモチーフが欠失したことに相当するアミノ酸配列を有するものということができる。 (A) A modified fibroin with a reduced content of n motif (third modified fibroin) is a domain sequence whose amino acid sequence has a reduced content of n motif compared to naturally occurring fibroin (A) Has an array. It can be said that the domain sequence of the third modified fibroin has an amino acid sequence corresponding to the deletion of at least one or more (A) n motifs, as compared to naturally occurring fibroin.
　第３の改変フィブロインは、天然由来のフィブロインから（Ａ）ｎモチーフを１０～４０％欠失させたことに相当するアミノ酸配列を有するものであってもよい。 The third modified fibroin may have an amino acid sequence corresponding to 10% to 40% deletion of the (A) n motif from naturally occurring fibroin.
　第３の改変フィブロインは、そのドメイン配列が、天然由来のフィブロインと比較して、少なくともＮ末端側からＣ末端側に向かって１～３つの（Ａ）ｎモチーフ毎に１つの（Ａ）ｎモチーフが欠失したことに相当するアミノ酸配列を有するものであってもよい。 The third modification fibroin its domain sequence, compared to the naturally occurring fibroin, at least from the N-terminal side toward the C-terminal one to three (A) n motif every one (A) n motif May have an amino acid sequence corresponding to deletion of.
　第３の改変フィブロインは、そのドメイン配列が、天然由来のフィブロインと比較して、少なくともＮ末端側からＣ末端側に向かって２つ連続した（Ａ）ｎモチーフの欠失、及び１つの（Ａ）ｎモチーフの欠失がこの順に繰り返されたことに相当するアミノ酸配列を有するものであってもよい。 The third modified fibroin has a domain sequence that is at least two consecutive from the N-terminal side to the C-terminal side compared to the naturally occurring fibroin (A) deletion of the n motif, and one (A ) It may have an amino acid sequence corresponding to the deletion of the n motif repeated in this order.
　第３の改変フィブロインは、そのドメイン配列が、少なくともＮ末端側からＣ末端側に向かって２つおきに（Ａ）ｎモチーフが欠失したことに相当するアミノ酸配列を有するものであってもよい。 The third modified fibroin may have an amino acid sequence whose domain sequence corresponds to that at least every two (A) n motifs are deleted from the N-terminal side to the C-terminal side. .
　第３の改変フィブロインは、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含み、Ｎ末端側からＣ末端側に向かって、隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのＲＥＰのアミノ酸残基数を順次比較して、アミノ酸残基数が少ないＲＥＰのアミノ酸残基数を１としたとき、他方のＲＥＰのアミノ酸残基数の比が１．８～１１．３となる隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのアミノ酸残基数を足し合わせた合計値の最大値をｘとし、ドメイン配列の総アミノ酸残基数をｙとしたときに、ｘ／ｙが２０％以上、３０％以上、４０％以上又は５０％以上であるアミノ酸配列を有するものであってもよい。（Ａ）ｎモチーフ中の全アミノ酸残基数に対するアラニン残基数は８３％以上であってよいが、８６％以上であることが好ましく、９０％以上であることがより好ましく、９５％以上であることが更に好ましく、１００％であること（アラニン残基のみで構成されることを意味する）が更により好ましい。 The third modified fibroin includes a domain sequence represented by Formula 1: [(A) n motif-REP] m , and two adjacent [(A) n motifs from the N-terminal side toward the C-terminal side. -REP] When the number of amino acid residues in the REP of the unit is sequentially compared, and the number of amino acid residues in the REP with a small number of amino acid residues is 1, the ratio of the number of amino acid residues in the other REP is 1.8 to When the maximum total value of the total number of amino acid residues of two adjacent [(A) n motif-REP] units that becomes 11.3 is x and the total number of amino acid residues in the domain sequence is y In addition, it may have an amino acid sequence in which x / y is 20% or more, 30% or more, 40% or more, or 50% or more. (A) The number of alanine residues relative to the total number of amino acid residues in the n motif may be 83% or more, preferably 86% or more, more preferably 90% or more, and 95% or more. More preferably, it is 100% (meaning that it is composed only of alanine residues).
　ｘ／ｙの算出方法を図１を参照しながら更に詳細に説明する。図１には、フィブロインからＮ末端配列及びＣ末端配列を除いたドメイン配列を示す。当該ドメイン配列は、Ｎ末端側（左側）から（Ａ）ｎモチーフ－第１のＲＥＰ（５０アミノ酸残基）－（Ａ）ｎモチーフ－第２のＲＥＰ（１００アミノ酸残基）－（Ａ）ｎモチーフ－第３のＲＥＰ（１０アミノ酸残基）－（Ａ）ｎモチーフ－第４のＲＥＰ（２０アミノ酸残基）－（Ａ）ｎモチーフ－第５のＲＥＰ（３０アミノ酸残基）－（Ａ）ｎモチーフという配列を有する。 The method for calculating x / y will be described in more detail with reference to FIG. FIG. 1 shows a domain sequence obtained by removing N-terminal sequence and C-terminal sequence from fibroin. The domain sequence is from the N-terminal side (left side): (A) n motif-first REP (50 amino acid residues)-(A) n motif-second REP (100 amino acid residues)-(A) n Motif-third REP (10 amino acid residues)-(A) n motif-fourth REP (20 amino acid residues)-(A) n motif-fifth REP (30 amino acid residues)-(A) It has a sequence called n motif.
　隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットは、重複がないように、Ｎ末端側からＣ末端側に向かって、順次選択する。このとき、選択されない［（Ａ）ｎモチーフ－ＲＥＰ］ユニットが存在してもよい。図１には、パターン１（第１のＲＥＰと第２のＲＥＰの比較、及び第３のＲＥＰと第４のＲＥＰの比較）、パターン２（第１のＲＥＰと第２のＲＥＰの比較、及び第４のＲＥＰと第５のＲＥＰの比較）、パターン３（第２のＲＥＰと第３のＲＥＰの比較、及び第４のＲＥＰと第５のＲＥＰの比較）、パターン４（第１のＲＥＰと第２のＲＥＰの比較）を示した。なお、これ以外にも選択方法は存在する。 Two adjacent [(A) n motif-REP] units are sequentially selected from the N-terminal side to the C-terminal side so as not to overlap. At this time, an unselected [(A) n motif-REP] unit may exist. FIG. 1 includes pattern 1 (comparison between the first REP and the second REP, and comparison between the third REP and the fourth REP), pattern 2 (comparison between the first REP and the second REP, and 4th REP and 5th REP), pattern 3 (2nd REP and 3rd REP comparison, 4th REP and 5th REP comparison), pattern 4 (first REP and Comparison of the second REP). There are other selection methods.
　次に各パターンについて、選択した隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニット中の各ＲＥＰのアミノ酸残基数を比較する。比較は、よりアミノ酸残基数の少ない方を１としたときの、他方のアミノ酸残基数の比を求めることによって行う。例えば、第１のＲＥＰ（５０アミノ酸残基）と第２のＲＥＰ（１００アミノ酸残基）の比較の場合、よりアミノ酸残基数の少ない第１のＲＥＰを１としたとき、第２のＲＥＰのアミノ酸残基数の比は、１００／５０＝２である。同様に、第４のＲＥＰ（２０アミノ酸残基）と第５のＲＥＰ（３０アミノ酸残基）の比較の場合、よりアミノ酸残基数の少ない第４のＲＥＰを１としたとき、第５のＲＥＰのアミノ酸残基数の比は、３０／２０＝１．５である。 Next, for each pattern, the number of amino acid residues of each REP in the two adjacent [(A) n motif-REP] units selected is compared. The comparison is performed by determining the ratio of the number of amino acid residues on the other side when the smaller number of amino acid residues is 1. For example, in the comparison of the first REP (50 amino acid residues) and the second REP (100 amino acid residues), when the first REP having a smaller number of amino acid residues is 1, the second REP The ratio of the number of amino acid residues is 100/50 = 2. Similarly, in the comparison of the fourth REP (20 amino acid residues) and the fifth REP (30 amino acid residues), when the fourth REP having a smaller number of amino acid residues is 1, the fifth REP The ratio of the number of amino acid residues is 30/20 = 1.5.
　図１中、よりアミノ酸残基数の少ない方を１としたときに、他方のアミノ酸残基数の比が１．８～１１．３となる［（Ａ）ｎモチーフ－ＲＥＰ］ユニットの組を実線で示した。以下このような比をギザ比率と呼ぶ。よりアミノ酸残基数の少ない方を１としたときに、他方のアミノ酸残基数の比が１．８未満又は１１．３超となる［（Ａ）ｎモチーフ－ＲＥＰ］ユニットの組は破線で示した。 In FIG. 1, when the smaller number of amino acid residues is 1, the ratio of the number of other amino acid residues is 1.8 to 11.3 [(A) n motif-REP] unit pairs Shown in solid line. Hereinafter, such a ratio is referred to as a jagged ratio. When the smaller number of amino acid residues is 1, the ratio of the number of other amino acid residues is less than 1.8 or more than 11.3. [(A) n motif-REP] unit pairs are indicated by broken lines. Indicated.
　各パターンにおいて、実線で示した隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットの全てのアミノ酸残基数を足し合わせる（ＲＥＰのみではなく、（Ａ）ｎモチーフのアミノ酸残基数もである。）。そして、足し合わせた合計値を比較して、当該合計値が最大となるパターンの合計値（合計値の最大値）をｘとする。図１に示した例では、パターン１の合計値が最大である。 In each pattern, the number of all amino acid residues of two adjacent [(A) n motif-REP] units indicated by solid lines is added (not only REP but also (A) the number of amino acid residues of the n motif. is there.). Then, the total value added is compared, and the total value (maximum value of the total value) of the pattern having the maximum total value is set as x. In the example shown in FIG. 1, the total value of pattern 1 is the maximum.
　次に、ｘをドメイン配列の総アミノ酸残基数ｙで除すことによって、ｘ／ｙ（％）を算出することができる。 Next, x / y (%) can be calculated by dividing x by the total number of amino acid residues y of the domain sequence.
　第３の改変フィブロインにおいて、ｘ／ｙは、５０％以上であることが好ましく、６０％以上であることがより好ましく、６５％以上であることが更に好ましく、７０％以上であることが更により好ましく、７５％以上であることが更によりまた好ましく、８０％以上であることが特に好ましい。ｘ／ｙの上限に特に制限はなく、例えば、１００％以下であってよい。ギザ比率が１：１．９～１１．３の場合には、ｘ／ｙは８９．６％以上であることが好ましく、ギザ比率が１：１．８～３．４の場合には、ｘ／ｙは７７．１％以上であることが好ましく、ギザ比率が１：１．９～８．４の場合には、ｘ／ｙは７５．９％以上であることが好ましく、ギザ比率が１：１．９～４．１の場合には、ｘ／ｙは６４．２％以上であることが好ましい。 In the third modified fibroin, x / y is preferably 50% or more, more preferably 60% or more, still more preferably 65% or more, and even more preferably 70% or more. Preferably, it is still more preferably 75% or more, and particularly preferably 80% or more. There is no restriction | limiting in particular in the upper limit of x / y, For example, you may be 100% or less. When the jagged ratio is 1: 1.9 to 11.3, x / y is preferably 89.6% or more, and when the jagged ratio is 1: 1.8 to 3.4, x / y / Y is preferably 77.1% or more, and when the jagged ratio is 1: 1.9 to 8.4, x / y is preferably 75.9% or more, and the jagged ratio is 1 In the case of 1.9 to 4.1, x / y is preferably 64.2% or more.
　第３の改変フィブロインが、ドメイン配列中に複数存在する（Ａ）ｎモチーフの少なくとも７つがアラニン残基のみで構成される改変フィブロインである場合、ｘ／ｙは、４６．４％以上であることが好ましく、５０％以上であることがより好ましく、５５％以上であることが更に好ましく、６０％以上であることが更により好ましく、７０％以上であることが更によりまた好ましく、８０％以上であることが特に好ましい。ｘ／ｙの上限に特に制限はなく、１００％以下であればよい。 A plurality of third modified fibroins are present in the domain sequence (A) When at least 7 of the n motifs are modified fibroins composed of only alanine residues, x / y is 46.4% or more It is preferably 50% or more, more preferably 55% or more, still more preferably 60% or more, still more preferably 70% or more, and more preferably 80% or more. It is particularly preferred. There is no restriction | limiting in particular in the upper limit of x / y, and what is necessary is just 100% or less.
　第３の改変フィブロインは、例えば、クローニングした天然由来のフィブロインの遺伝子配列から、ｘ／ｙが６４．２％以上になるように（Ａ）ｎモチーフをコードする配列の１又は複数を欠失させることにより得ることができる。また、例えば、天然由来のフィブロインのアミノ酸配列から、ｘ／ｙが６４．２％以上になるように１又は複数の（Ａ）ｎモチーフが欠失したことに相当するアミノ酸配列を設計し、設計したアミノ酸配列をコードする核酸を化学合成することにより得ることもできる。いずれの場合においても、天然由来のフィブロインのアミノ酸配列から（Ａ）ｎモチーフが欠失したことに相当する改変に加え、更に１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変を行ってもよい。 In the third modified fibroin, for example, one or a plurality of sequences encoding the n motif is deleted so that x / y is 64.2% or more from the cloned gene sequence of naturally occurring fibroin. Can be obtained. In addition, for example, an amino acid sequence corresponding to the deletion of one or more (A) n motifs is designed so that x / y is 64.2% or more from the amino acid sequence of naturally occurring fibroin. It can also be obtained by chemically synthesizing a nucleic acid encoding the amino acid sequence. In any case, in addition to the modification corresponding to the deletion of the (A) n motif from the amino acid sequence of naturally occurring fibroin, one or more amino acid residues are further substituted, deleted, inserted and / or added. The amino acid sequence corresponding to this may be modified.
　第３の改変フィブロインのより具体的な例として、（３－ｉ）配列番号１８、配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列、又は（３－ｉｉ）配列番号１８、配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As more specific examples of the third modified fibroin, (3-i) SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, or (3-ii) SEQ ID NO: 18, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 7, SEQ ID No. 8 or SEQ ID No. 9.
　（３－ｉ）の改変フィブロインについて説明する。配列番号１８で示されるアミノ酸配列は、天然由来のフィブロインに相当する配列番号１０で示されるアミノ酸配列から、Ｎ末端側からＣ末端側に向かって２つおきに（Ａ）ｎモチーフを欠失させ、更にＣ末端配列の手前に［（Ａ）ｎモチーフ－ＲＥＰ］を１つ挿入したものである。配列番号７で示されるアミノ酸配列は、配列番号１８で示されるアミノ酸配列のＲＥＰ中の全てのＧＧＸをＧＱＸに置換したものである。配列番号８で示されるアミノ酸配列は、配列番号７で示されるアミノ酸配列の各（Ａ）ｎモチーフのＣ末端側に２つのアラニン残基を挿入し、更に一部のグルタミン（Ｑ）残基をセリン（Ｓ）残基に置換し、配列番号７の分子量とほぼ同じとなるようにＮ末端側の一部のアミノ酸を欠失させたものである。配列番号９で示されるアミノ酸配列は、配列番号１１で示されるアミノ酸配列中に存在する２０個のドメイン配列の領域（但し、当該領域のＣ末端側の数アミノ酸残基が置換されている。）を４回繰り返した配列のＣ末端にＨｉｓタグが付加されたものである。 The modified fibroin (3-i) will be described. The amino acid sequence represented by SEQ ID NO: 18 is the amino acid sequence represented by SEQ ID NO: 10 corresponding to naturally occurring fibroin, wherein (A) n motif is deleted every two from the N-terminal side to the C-terminal side. Furthermore, one [(A) n motif-REP] is inserted in front of the C-terminal sequence. The amino acid sequence shown in SEQ ID NO: 7 is obtained by substituting all GGX in REP of the amino acid sequence shown in SEQ ID NO: 18 with GQX. The amino acid sequence represented by SEQ ID NO: 8 has two alanine residues inserted at the C-terminal side of each (A) n motif of the amino acid sequence represented by SEQ ID NO: 7, and a part of glutamine (Q) residues. Substituted with a serine (S) residue and a part of the amino acid at the N-terminal side was deleted so as to be almost the same as the molecular weight of SEQ ID NO: 7. The amino acid sequence shown in SEQ ID NO: 9 is a region of 20 domain sequences present in the amino acid sequence shown in SEQ ID NO: 11 (however, several amino acid residues on the C-terminal side of the region are substituted). Is a sequence in which a His tag is added to the C-terminal of the sequence repeated four times.
　配列番号１０で示されるアミノ酸配列（天然由来のフィブロインに相当）のギザ比率１：１．８～１１．３におけるｘ／ｙの値は１５．０％である。配列番号１８で示されるアミノ酸配列、及び配列番号７で示されるアミノ酸配列におけるｘ／ｙの値は、いずれも９３．４％である。配列番号８で示されるアミノ酸配列におけるｘ／ｙの値は、９２．７％である。配列番号９で示されるアミノ酸配列におけるｘ／ｙの値は、８９．３％である。配列番号１０、配列番号１８、配列番号７、配列番号８及び配列番号９で示されるアミノ酸配列におけるｚ／ｗの値は、それぞれ４６．８％、５６．２％、７０．１％、６６．１％及び７０．０％である。 The value of x / y in the amino acid sequence represented by SEQ ID NO: 10 (corresponding to naturally-occurring fibroin) at a jagged ratio of 1: 1.8 to 11.3 is 15.0%. The value of x / y in the amino acid sequence shown by SEQ ID NO: 18 and the amino acid sequence shown by SEQ ID NO: 7 are both 93.4%. The value of x / y in the amino acid sequence represented by SEQ ID NO: 8 is 92.7%. The value of x / y in the amino acid sequence represented by SEQ ID NO: 9 is 89.3%. The z / w values in the amino acid sequences represented by SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 and SEQ ID NO: 9 are 46.8%, 56.2%, 70.1% and 66. respectively. 1% and 70.0%.
　（３－ｉ）の改変フィブロインは、配列番号１８、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (3-i) may consist of the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9.
　（３－ｉｉ）の改変フィブロインは、配列番号１８、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（３－ｉｉ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (3-ii) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9. The modified fibroin of (3-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m. The sequence identity is preferably 95% or more.
　（３－ｉｉ）の改変フィブロインは、配列番号１８、配列番号７、配列番号８又は配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつＮ末端側からＣ末端側に向かって、隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのＲＥＰのアミノ酸残基数を順次比較して、アミノ酸残基数が少ないＲＥＰのアミノ酸残基数を１としたとき、他方のＲＥＰのアミノ酸残基数の比が１．８～１１．３（ギザ比率が１：１．８～１１．３）となる隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのアミノ酸残基数を足し合わせた合計値の最大値をｘとし、ドメイン配列の総アミノ酸残基数をｙとしたときに、ｘ／ｙが６４．２％以上であることが好ましい。 The modified fibroin of (3-ii) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 18, SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, and from the N-terminal side to the C-terminal side When the number of amino acid residues of REP of two adjacent [(A) n motif-REP] units is sequentially compared, and the number of amino acid residues of REP having a small number of amino acid residues is 1, the other The amino acid residues of two adjacent [(A) n motif-REP] units with a ratio of the number of amino acid residues of REP of 1.8 to 11.3 (giza ratio is 1: 1.8 to 11.3) It is preferable that x / y is 64.2% or more, where x is the maximum total value of the total number of bases and y is the total number of amino acid residues in the domain sequence.
　第３の改変フィブロインは、Ｎ末端及びＣ末端のいずれか一方又は両方に上述したタグ配列を含んでいてもよい。 The third modified fibroin may contain the tag sequence described above at one or both of the N-terminal and C-terminal.
　タグ配列を含む第３の改変フィブロインのより具体的な例として、（３－ｉｉｉ）配列番号１７、配列番号１１、配列番号１４若しくは配列番号１５で示されるアミノ酸配列、又は（３－ｉｖ）配列番号１７、配列番号１１、配列番号１４若しくは配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As a more specific example of the third modified fibroin containing the tag sequence, (3-iii) SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, or (3-iv) sequence Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
　配列番号１６、配列番号１７、配列番号１３、配列番号１１、配列番号１４及び配列番号１５で示されるアミノ酸配列は、それぞれ配列番号１０、配列番号１８、配列番号６、配列番号７、配列番号８及び配列番号９で示されるアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（Ｈｉｓタグ配列及びヒンジ配列を含む）を付加したものである。 The amino acid sequences represented by SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 13, SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15 are SEQ ID NO: 10, SEQ ID NO: 18, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, respectively. And an amino acid sequence represented by SEQ ID NO: 12 (including a His tag sequence and a hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 9.
　（３－ｉｉｉ）の改変フィブロインは、配列番号１７、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列からなるものであってもよい。 (3-iii) The modified fibroin may be composed of the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15.
　（３－ｉｖ）の改変フィブロインは、配列番号１７、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（３－ｉｖ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (3-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15. The modified fibroin of (3-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m . The sequence identity is preferably 95% or more.
　（３－ｉｖ）の改変フィブロインは、配列番号１７、配列番号１１、配列番号１４又は配列番号１５で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつＮ末端側からＣ末端側に向かって、隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのＲＥＰのアミノ酸残基数を順次比較して、アミノ酸残基数が少ないＲＥＰのアミノ酸残基数を１としたとき、他方のＲＥＰのアミノ酸残基数の比が１．８～１１．３となる隣合う２つの［（Ａ）ｎモチーフ－ＲＥＰ］ユニットのアミノ酸残基数を足し合わせた合計値の最大値をｘとし、ドメイン配列の総アミノ酸残基数をｙとしたときに、ｘ／ｙが６４．２％以上であることが好ましい。 The modified fibroin (3-iv) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 17, SEQ ID NO: 11, SEQ ID NO: 14 or SEQ ID NO: 15, and from the N-terminal side to the C-terminal side. When the number of amino acid residues of REP of two adjacent [(A) n motif-REP] units is sequentially compared, and the number of amino acid residues of REP having a small number of amino acid residues is 1, the other X is the maximum total value of the total number of amino acid residues of two adjacent [(A) n motif-REP] units with a ratio of the number of amino acid residues of REP of 1.8 to 11.3. When the total number of amino acid residues of the domain sequence is y, x / y is preferably 64.2% or more.
　第３の改変フィブロインは、組換えタンパク質生産系において生産されたタンパク質を宿主の外部に放出するための分泌シグナルを含んでいてもよい。分泌シグナルの配列は、宿主の種類に応じて適宜設定することができる。 The third modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host. The sequence of the secretion signal can be appropriately set according to the type of host.
　グリシン残基の含有量、及び（Ａ）ｎモチーフの含有量が低減された改変フィブロイン（第４の改変フィブロイン）は、そのドメイン配列が、天然由来のフィブロインと比較して、（Ａ）ｎモチーフの含有量が低減されたことに加え、グリシン残基の含有量が低減されたアミノ酸配列を有するものである。第４の改変フィブロインのドメイン配列は、天然由来のフィブロインと比較して、少なくとも１又は複数の（Ａ）ｎモチーフが欠失したことに加え、更に少なくともＲＥＰ中の１又は複数のグリシン残基が別のアミノ酸残基に置換されたことに相当するアミノ酸配列を有するものということができる。すなわち、第４の改変フィブロインは、上述したグリシン残基の含有量が低減された改変フィブロイン（第２の改変フィブロイン）と、（Ａ）ｎモチーフの含有量が低減された改変フィブロイン（第３の改変フィブロイン）の特徴を併せ持つ改変フィブロインである。具体的な態様等は、第２の改変フィブロイン、及び第３の改変フィブロインで説明したとおりである。 The content of glycine residues, and (A) n motifs modified fibroin content is reduced in the (fourth modified fibroin), the domain sequence is compared to the naturally occurring fibroin, (A) n motif In addition to having a reduced content of glycine residues, it has an amino acid sequence with a reduced content of glycine residues. The domain sequence of the fourth modified fibroin has at least one or more (A) n motifs deleted as compared to naturally occurring fibroin, and at least one or more glycine residues in the REP. It can be said to have an amino acid sequence corresponding to the substitution with another amino acid residue. That is, the fourth modified fibroin includes the modified fibroin (second modified fibroin) in which the content of the glycine residue described above is reduced, and (A) the modified fibroin (third in which the content of the n motif is reduced). It is a modified fibroin having the characteristics of modified fibroin). Specific embodiments and the like are as described in the second modified fibroin and the third modified fibroin.
　第４の改変フィブロインのより具体的な例として、（４－ｉ）配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列、（４－ｉｉ）配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。配列番号７、配列番号８若しくは配列番号９で示されるアミノ酸配列を含む改変フィブロインの具体的な態様は上述のとおりである。 As more specific examples of the fourth modified fibroin, (4-i) the amino acid sequence represented by SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9, (4-ii) SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in FIG. Specific embodiments of the modified fibroin comprising the amino acid sequence represented by SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9 are as described above.
　局所的に疎水性指標の大きい領域を含むドメイン配列を有する改変フィブロイン（第５の改変フィブロイン）は、そのドメイン配列が、天然由来のフィブロインと比較して、ＲＥＰ中の１又は複数のアミノ酸残基が疎水性指標の大きいアミノ酸残基に置換されたこと、及び／又はＲＥＰ中に１又は複数の疎水性指標の大きいアミノ酸残基が挿入されたことに相当する、局所的に疎水性指標の大きい領域を含むアミノ酸配列を有するものであってよい。 A modified fibroin having a domain sequence that locally includes a region having a large hydrophobicity index (fifth modified fibroin) has a domain sequence of one or more amino acid residues in REP as compared to naturally occurring fibroin. Has a large hydrophobicity index, which is equivalent to substitution of an amino acid residue having a large hydrophobicity index and / or insertion of one or more amino acid residues having a large hydrophobicity index into REP. It may have an amino acid sequence including a region.
　局所的に疎水性指標の大きい領域は、連続する２～４アミノ酸残基で構成されていることが好ましい。 The region where the hydrophobic index is locally large is preferably composed of 2 to 4 amino acid residues.
　上述の疎水性指標の大きいアミノ酸残基は、イソロイシン（Ｉ）、バリン（Ｖ）、ロイシン（Ｌ）、フェニルアラニン（Ｆ）、システイン（Ｃ）、メチオニン（Ｍ）及びアラニン（Ａ）から選ばれるアミノ酸残基であることがより好ましい。 The amino acid residue having a large hydrophobicity index is an amino acid selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A). More preferably, it is a residue.
　第５の改変フィブロインは、天然由来のフィブロインと比較して、ＲＥＰ中の１又は複数のアミノ酸残基が疎水性指標の大きいアミノ酸残基に置換されたこと、及び／又はＲＥＰ中に１又は複数の疎水性指標の大きいアミノ酸残基が挿入されたことに相当する改変に加え、更に、天然由来のフィブロインと比較して、１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変があってもよい。 The fifth modified fibroin has one or more amino acid residues in REP substituted with amino acid residues having a higher hydrophobicity index and / or one or more in REP compared to naturally occurring fibroin. In addition to the modification corresponding to the insertion of an amino acid residue having a large hydrophobicity index, further, substitution, deletion, insertion and / or addition of one or more amino acid residues as compared with naturally occurring fibroin There may be amino acid sequence modifications corresponding to the above.
　第５の改変フィブロインは、例えば、クローニングした天然由来のフィブロインの遺伝子配列からＲＥＰ中の１又は複数の親水性アミノ酸残基（例えば、疎水性指標がマイナスであるアミノ酸残基）を疎水性アミノ酸残基（例えば、疎水性指標がプラスであるアミノ酸残基）に置換すること、及び／又はＲＥＰ中に１又は複数の疎水性アミノ酸残基を挿入することにより得ることができる。また、例えば、天然由来のフィブロインのアミノ酸配列からＲＥＰ中の１又は複数の親水性アミノ酸残基を疎水性アミノ酸残基に置換したこと、及び／又はＲＥＰ中に１又は複数の疎水性アミノ酸残基を挿入したことに相当するアミノ酸配列を設計し、設計したアミノ酸配列をコードする核酸を化学合成することにより得ることもできる。いずれの場合においても、天然由来のフィブロインのアミノ酸配列からＲＥＰ中の１又は複数の親水性アミノ酸残基を疎水性アミノ酸残基に置換したこと、及び／又はＲＥＰ中に１又は複数の疎水性アミノ酸残基を挿入したことに相当する改変に加え、更に１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変を行ってもよい。 For example, the fifth modified fibroin is obtained by removing one or more hydrophilic amino acid residues (for example, amino acid residues having a negative hydrophobicity index) in the REP from the cloned natural fibroin gene sequence. It can be obtained by substituting a group (for example, an amino acid residue having a positive hydrophobicity index) and / or inserting one or more hydrophobic amino acid residues in REP. In addition, for example, one or more hydrophilic amino acid residues in REP are substituted with hydrophobic amino acid residues from the amino acid sequence of naturally occurring fibroin, and / or one or more hydrophobic amino acid residues in REP It can also be obtained by designing an amino acid sequence corresponding to insertion of, and chemically synthesizing a nucleic acid encoding the designed amino acid sequence. In any case, one or more hydrophilic amino acid residues in REP have been replaced with hydrophobic amino acid residues from the amino acid sequence of naturally occurring fibroin and / or one or more hydrophobic amino acids in REP In addition to the modification corresponding to the insertion of a residue, the amino acid sequence corresponding to the substitution, deletion, insertion and / or addition of one or more amino acid residues may be further modified.
　第５の改変フィブロインは、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含み、最もＣ末端側に位置する（Ａ）ｎモチーフから上記ドメイン配列のＣ末端までの配列を上記ドメイン配列から除いた配列に含まれる全てのＲＥＰにおいて、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域に含まれるアミノ酸残基の総数をｐとし、最もＣ末端側に位置する（Ａ）ｎモチーフから上記ドメイン配列のＣ末端までの配列を上記ドメイン配列から除いた配列に含まれるアミノ酸残基の総数をｑとしたときに、ｐ／ｑが６．２％以上であるアミノ酸配列を有してもよい。 The fifth modified fibroin comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and is located on the most C-terminal side (A) from the n motif to the C terminus of the domain sequence. In all REPs included in the sequence excluding the sequence from the domain sequence, p is the total number of amino acid residues included in the region where the average value of the hydrophobicity index of four consecutive amino acid residues is 2.6 or more, (A) When the total number of amino acid residues contained in the sequence excluding the sequence from the n motif to the C terminus of the domain sequence, which is located at the most C-terminal side, from the domain sequence is q, p / q is 6 It may have an amino acid sequence that is 2% or more.
　アミノ酸残基の疎水性指標については、公知の指標（Ｈｙｄｒｏｐａｔｈｙ　ｉｎｄｅｘ：Ｋｙｔｅ　Ｊ，＆Ｄｏｏｌｉｔｔｌｅ　Ｒ（１９８２）“Ａ　ｓｉｍｐｌｅ　ｍｅｔｈｏｄ　ｆｏｒ　ｄｉｓｐｌａｙｉｎｇ　ｔｈｅ　ｈｙｄｒｏｐａｔｈｉｃ　ｃｈａｒａｃｔｅｒ　ｏｆ　ａ　ｐｒｏｔｅｉｎ”，Ｊ．Ｍｏｌ．Ｂｉｏｌ．，１５７，ｐｐ．１０５－１３２）を使用する。具体的には、各アミノ酸の疎水性指標（ハイドロパシー・インデックス、以下「ＨＩ」とも記す。）は、下記表１に示すとおりである。 As for the hydrophobicity index of amino acid residues, a known index (Hydropathy index: Kyte J, & Doolittle R (1982) “A simple method for displaying the hydropathic character of bio.p. 7”. 105-132). Specifically, the hydrophobicity index (hydropathic index, hereinafter also referred to as “HI”) of each amino acid is as shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　ｐ／ｑの算出方法を更に詳細に説明する。算出には、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列から、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列を除いた配列（以下、「配列Ａ」とする）を用いる。まず、配列Ａに含まれる全てのＲＥＰにおいて、連続する４アミノ酸残基の疎水性指標の平均値を算出する。疎水性指標の平均値は、連続する４アミノ酸残基に含まれる各アミノ酸残基のＨＩの総和を４（アミノ酸残基数）で除して求める。疎水性指標の平均値は、全ての連続する４アミノ酸残基について求める（各アミノ酸残基は、１～４回平均値の算出に用いられる。）。次いで、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域を特定する。あるアミノ酸残基が、複数の「疎水性指標の平均値が２．６以上となる連続する４アミノ酸残基」に該当する場合であっても、領域中には１アミノ酸残基として含まれることになる。そして、当該領域に含まれるアミノ酸残基の総数がｐである。また、配列Ａに含まれるアミノ酸残基の総数がｑである。 The method for calculating p / q will be described in more detail. For the calculation, a sequence obtained by removing the sequence from the domain sequence represented by Formula 1: [(A) n motif-REP] m to the most C-terminal side from the domain (A) n motif to the C terminus of the domain sequence. (Hereinafter referred to as “array A”). First, in all REPs included in the sequence A, the average value of the hydrophobicity index of four consecutive amino acid residues is calculated. The average value of the hydrophobicity index is obtained by dividing the total HI of each amino acid residue contained in the four consecutive amino acid residues by 4 (number of amino acid residues). The average value of the hydrophobicity index is obtained for all four consecutive amino acid residues (each amino acid residue is used for calculating the average value 1 to 4 times). Next, a region where the average value of the hydrophobicity index of four consecutive amino acid residues is 2.6 or more is specified. Even if a certain amino acid residue corresponds to a plurality of “four consecutive amino acid residues whose average value of hydrophobicity index is 2.6 or more”, it should be included as one amino acid residue in the region. become. The total number of amino acid residues contained in the region is p. The total number of amino acid residues contained in sequence A is q.
　例えば、「疎水性指標の平均値が２．６以上となる連続する４アミノ酸残基」が２０カ所抽出された場合（重複はなし）、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域には、連続する４アミノ酸残基（重複はなし）が２０含まれることになり、ｐは２０×４＝８０である。また、例えば、２つの「疎水性指標の平均値が２．６以上となる連続する４アミノ酸残基」が１アミノ酸残基だけ重複して存在する場合、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域には、７アミノ酸残基含まれることになる（ｐ＝２×４－１＝７。「－１」は重複分の控除である。）。例えば、図２に示したドメイン配列の場合、「疎水性指標の平均値が２．６以上となる連続する４アミノ酸残基」が重複せずに７つ存在するため、ｐは７×４＝２８となる。また、例えば、図２に示したドメイン配列の場合、ｑは４＋５０＋４＋４０＋４＋１０＋４＋２０＋４＋３０＝１７０である（Ｃ末端側の最後に存在する（Ａ）ｎモチーフは含めない）。次に、ｐをｑで除すことによって、ｐ／ｑ（％）を算出することができる。図２の場合２８／１７０＝１６．４７％となる。 For example, when 20 “four consecutive amino acid residues with an average value of hydrophobicity index of 2.6 or more” are extracted (no overlap), the average value of the hydrophobicity index of four consecutive amino acid residues is 2 The region of .6 or more contains 20 consecutive 4 amino acid residues (no overlap), and p is 20 × 4 = 80. In addition, for example, when two “four consecutive amino acid residues having an average value of hydrophobicity index of 2.6 or more” overlap by one amino acid residue, the hydrophobicity index of four consecutive amino acid residues In the region where the average value of is 2.6 or more, 7 amino acid residues are included (p = 2 × 4-1 = 7, where “−1” is a deduction of duplicates). For example, in the case of the domain sequence shown in FIG. 2, there are 7 “4 consecutive amino acid residues with an average value of hydrophobicity index of 2.6 or more” without duplication, and therefore p is 7 × 4 = 28. For example, in the case of the domain sequence shown in FIG. 2, q is 4 + 50 + 4 + 40 + 4 + 10 + 4 + 20 + 4 + 30 = 170 (the (A) n motif present at the end on the C-terminal side is not included). Next, p / q (%) can be calculated by dividing p by q. In the case of FIG. 2, 28/170 = 16.47%.
　第５の改変フィブロインにおいて、ｐ／ｑは、６．２％以上であることが好ましく、７％以上であることがより好ましく、１０％以上であることが更に好ましく、２０％以上であることが更により好ましく、３０％以上であることが更によりまた好ましい。ｐ／ｑの上限は、特に制限されないが、例えば、４５％以下であってもよい。 In the fifth modified fibroin, p / q is preferably 6.2% or more, more preferably 7% or more, further preferably 10% or more, and preferably 20% or more. Even more preferably, it is still more preferably 30% or more. The upper limit of p / q is not particularly limited, but may be 45% or less, for example.
　第５の改変フィブロインは、例えば、クローニングした天然由来のフィブロインのアミノ酸配列を、上記のｐ／ｑの条件を満たすように、ＲＥＰ中の１又は複数の親水性アミノ酸残基（例えば、疎水性指標がマイナスであるアミノ酸残基）を疎水性アミノ酸残基（例えば、疎水性指標がプラスであるアミノ酸残基）に置換すること、及び／又はＲＥＰ中に１又は複数の疎水性アミノ酸残基を挿入することにより、局所的に疎水性指標の大きい領域を含むアミノ酸配列に改変することにより得ることができる。また、例えば、天然由来のフィブロインのアミノ酸配列から上記のｐ／ｑの条件を満たすアミノ酸配列を設計し、設計したアミノ酸配列をコードする核酸を化学合成することにより得ることもできる。いずれの場合においても、天然由来のフィブロインと比較して、ＲＥＰ中の１又は複数のアミノ酸残基が疎水性指標の大きいアミノ酸残基に置換されたこと、及び／又はＲＥＰ中に１又は複数の疎水性指標の大きいアミノ酸残基が挿入されたことに相当する改変に加え、更に１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当する改変を行ってもよい。 The fifth modified fibroin is, for example, one or a plurality of hydrophilic amino acid residues (for example, a hydrophobicity index) in the REP so that the amino acid sequence of the naturally-derived fibroin thus cloned satisfies the above p / q condition. Is replaced with a hydrophobic amino acid residue (for example, an amino acid residue with a positive hydrophobicity index) and / or one or more hydrophobic amino acid residues are inserted in the REP By doing so, it can be obtained by locally modifying the amino acid sequence to include a region having a large hydrophobicity index. Alternatively, for example, an amino acid sequence satisfying the above p / q conditions can be designed from the amino acid sequence of naturally derived fibroin, and a nucleic acid encoding the designed amino acid sequence can be obtained by chemical synthesis. In any case, compared to naturally occurring fibroin, one or more amino acid residues in REP were replaced with amino acid residues having a higher hydrophobicity index and / or one or more amino acid residues in REP. In addition to modifications corresponding to insertion of amino acid residues having a large hydrophobicity index, modifications corresponding to substitution, deletion, insertion and / or addition of one or more amino acid residues may be performed. .
　疎水性指標の大きいアミノ酸残基としては、特に制限はないが、イソロイシン（Ｉ）、バリン（Ｖ）、ロイシン（Ｌ）、フェニルアラニン（Ｆ）、システイン（Ｃ）、メチオニン（Ｍ）及びアラニン（Ａ）が好ましく、バリン（Ｖ）、ロイシン（Ｌ）及びイソロイシン（Ｉ）がより好ましい。 The amino acid residue having a large hydrophobicity index is not particularly limited, but isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A ) Are preferred, and valine (V), leucine (L) and isoleucine (I) are more preferred.
　第５の改変フィブロインの具体的な例として、（５－ｉ）配列番号１９、配列番号２０若しくは配列番号２１で示されるアミノ酸配列、又は（５－ｉｉ）配列番号１９、配列番号２０若しくは配列番号２１で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As specific examples of the fifth modified fibroin, (5-i) the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21, or (5-ii) SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of 90% or more with the amino acid sequence shown in FIG.
　（５－ｉ）の改変フィブロインについて説明する。配列番号２２で示されるアミノ酸配列は、天然由来のフィブロインの（Ａ）ｎモチーフ中のアラニン残基が連続するアミノ酸配列をアラニン残基が連続する数を５つになるよう欠失したものである。配列番号１９で示されるアミノ酸配列は、配列番号２２で示されるアミノ酸配列に対し、ＲＥＰ一つ置きにそれぞれ３アミノ酸残基からなるアミノ酸配列（ＶＬＩ）を２カ所挿入し、かつ配列番号２２で示されるアミノ酸配列の分子量とほぼ同じとなるようにＣ末端側の一部のアミノ酸を欠失させたものである。配列番号２３で示されるアミノ酸配列は、配列番号２２で示されるアミノ酸配列に対し、各（Ａ）ｎモチーフのＣ末端側に２つのアラニン残基を挿入し、更に一部のグルタミン（Ｑ）残基をセリン（Ｓ）残基に置換し、かつ配列番号２２で示されるアミノ酸配列の分子量とほぼ同じとなるようにＣ末端側の一部のアミノ酸を欠失させたものである。配列番号２０で示されるアミノ酸配列は、配列番号２３で示されるアミノ酸配列に対し、ＲＥＰ一つ置きにそれぞれ３アミノ酸残基からなるアミノ酸配列（ＶＬＩ）を１カ所挿入したものである。配列番号２１で示されるアミノ酸配列は、配列番号２３で示されるアミノ酸配列に対し、ＲＥＰ一つ置きにそれぞれ３アミノ酸残基からなるアミノ酸配列（ＶＬＩ）を２カ所挿入したものである。 The modified fibroin (5-i) will be described. The amino acid sequence represented by SEQ ID NO: 22 is an amino acid sequence in which alanine residues in the (A) n motif of (A) naturally derived fibroin are deleted so that the number of consecutive alanine residues is five. . The amino acid sequence represented by SEQ ID NO: 19 has two amino acid sequences (VLI) each consisting of 3 amino acid residues inserted into every other REP with respect to the amino acid sequence represented by SEQ ID NO: 22, and represented by SEQ ID NO: 22. A part of amino acids on the C-terminal side are deleted so that the molecular weight of the amino acid sequence is almost the same. The amino acid sequence represented by SEQ ID NO: 23 is obtained by inserting two alanine residues to the C-terminal side of each (A) n motif with respect to the amino acid sequence represented by SEQ ID NO: 22, and further adding some glutamine (Q) residues. A group is substituted with a serine (S) residue, and a part of amino acids on the C-terminal side is deleted so as to be approximately the same as the molecular weight of the amino acid sequence represented by SEQ ID NO: 22. The amino acid sequence represented by SEQ ID NO: 20 is obtained by inserting one amino acid sequence (VLI) consisting of 3 amino acid residues every other REP to the amino acid sequence represented by SEQ ID NO: 23. The amino acid sequence shown in SEQ ID NO: 21 is obtained by inserting two amino acid sequences (VLI) each consisting of 3 amino acid residues into the amino acid sequence shown in SEQ ID NO: 23 every other REP.
　（５－ｉ）の改変フィブロインは、配列番号１９、配列番号２０又は配列番号２１で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (5-i) may be composed of the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21.
　（５－ｉｉ）の改変フィブロインは、配列番号１９、配列番号２０又は配列番号２１で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（５－ｉｉ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (5-ii) comprises an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21. The modified fibroin of (5-ii) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m . The sequence identity is preferably 95% or more.
　（５－ｉｉ）の改変フィブロインは、配列番号１９、配列番号２０又は配列番号２１で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつ最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列に含まれる全てのＲＥＰにおいて、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域に含まれるアミノ酸残基の総数をｐとし、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列に含まれるアミノ酸残基の総数をｑとしたときに、ｐ／ｑが６．２％以上であることが好ましい。 The modified fibroin of (5-ii) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21, and is located on the most C-terminal side (A) n In all REPs included in the sequence excluding the sequence from the motif to the C-terminal of the domain sequence, the amino acids included in the region where the average value of the hydrophobicity index of 4 consecutive amino acid residues is 2.6 or more P is the total number of residues, and (A) When the total number of amino acid residues contained in the sequence excluding the sequence from the n motif to the C terminus of the domain sequence from the domain sequence is q , P / q is preferably 6.2% or more.
　第５の改変フィブロインは、Ｎ末端及びＣ末端のいずれか一方又は両方にタグ配列を含んでいてもよい。 The fifth modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal.
　タグ配列を含む第５の改変フィブロインのより具体的な例として、（５－ｉｉｉ）配列番号２４、配列番号２５若しくは配列番号２６で示されるアミノ酸配列、又は（５－ｉｖ）配列番号２４、配列番号２５若しくは配列番号２６で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As a more specific example of the fifth modified fibroin containing a tag sequence, (5-iii) the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26, or (5-iv) SEQ ID NO: 24, sequence Mention may be made of modified fibroin comprising an amino acid sequence having 90% or more sequence identity with the amino acid sequence shown in No. 25 or SEQ ID No. 26.
　配列番号２４、配列番号２５及び配列番号２６で示されるアミノ酸配列は、それぞれ配列番号１９、配列番号２０及び配列番号２１で示されるアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（Ｈｉｓタグ配列及びヒンジ配列を含む）を付加したものである。 The amino acid sequences represented by SEQ ID NO: 24, SEQ ID NO: 25, and SEQ ID NO: 26 are the amino acid sequences represented by SEQ ID NO: 12 at the N-terminus of the amino acid sequences represented by SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21, respectively (His tag). Including a sequence and a hinge sequence).
　（５－ｉｉｉ）の改変フィブロインは、配列番号２４、配列番号２５若しくは配列番号２６で示されるアミノ酸配列からなるものであってもよい。 (5-iii) The modified fibroin may consist of the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26.
　（５－ｉｖ）の改変フィブロインは、配列番号２４、配列番号２５若しくは配列番号２６で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（５－ｉｖ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin (5-iv) includes an amino acid sequence having 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26. The modified fibroin of (5-iv) is also a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m . The sequence identity is preferably 95% or more.
　（５－ｉｖ）の改変フィブロインは、配列番号２４、配列番号２５若しくは配列番号２６で示されるアミノ酸配列と９０％以上の配列同一性を有し、かつ最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列に含まれる全てのＲＥＰにおいて、連続する４アミノ酸残基の疎水性指標の平均値が２．６以上となる領域に含まれるアミノ酸残基の総数をｐとし、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列に含まれるアミノ酸残基の総数をｑとしたときに、ｐ／ｑが６．２％以上であることが好ましい。 The modified fibroin (5-iv) has 90% or more sequence identity with the amino acid sequence represented by SEQ ID NO: 24, SEQ ID NO: 25 or SEQ ID NO: 26, and is located at the most C-terminal side (A) n In all REPs included in the sequence excluding the sequence from the motif to the C-terminal of the domain sequence, the amino acids included in the region where the average value of the hydrophobicity index of 4 consecutive amino acid residues is 2.6 or more P is the total number of residues, and (A) When the total number of amino acid residues contained in the sequence excluding the sequence from the n motif to the C terminus of the domain sequence from the domain sequence is q , P / q is preferably 6.2% or more.
　第５の改変フィブロインは、組換えタンパク質生産系において生産されたタンパク質を宿主の外部に放出するための分泌シグナルを含んでいてもよい。分泌シグナルの配列は、宿主の種類に応じて適宜設定することができる。 The fifth modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host. The sequence of the secretion signal can be appropriately set according to the type of host.
　グルタミン残基の含有量が低減されたドメイン配列を有する改変フィブロイン（第６の改変フィブロイン）は、天然由来のフィブロインと比較して、グルタミン残基の含有量が低減されたアミノ酸配列を有する。 The modified fibroin having a domain sequence in which the content of glutamine residues is reduced (sixth modified fibroin) has an amino acid sequence in which the content of glutamine residues is reduced compared to naturally occurring fibroin.
　第６の改変フィブロインは、ＲＥＰのアミノ酸配列中に、ＧＧＸモチーフ及びＧＰＧＸＸモチーフから選ばれる少なくとも一つのモチーフが含まれていることが好ましい。 The sixth modified fibroin preferably contains at least one motif selected from GGX motif and GPGXX motif in the amino acid sequence of REP.
　第６の改変フィブロインが、ＲＥＰ中にＧＰＧＸＸモチーフを含む場合、ＧＰＧＸＸモチーフ含有率は、通常１％以上であり、５％以上であってもよく、１０％以上であるのが好ましい。ＧＰＧＸＸモチーフ含有率の上限に特に制限はなく、５０％以下であってよく、３０％以下であってもよい。 When the sixth modified fibroin contains a GPGXX motif in REP, the content ratio of the GPGXX motif is usually 1% or more, may be 5% or more, and is preferably 10% or more. There is no restriction | limiting in particular in the upper limit of GPGXX motif content rate, 50% or less may be sufficient and 30% or less may be sufficient.
　本明細書において、「ＧＰＧＸＸモチーフ含有率」は、以下の方法により算出される値である。
　式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むフィブロインにおいて、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列に含まれる全てのＲＥＰにおいて、その領域に含まれるＧＰＧＸＸモチーフの個数の総数を３倍した数（即ち、ＧＰＧＸＸモチーフ中のＧ及びＰの総数に相当）をｓとし、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除き、更に（Ａ）ｎモチーフを除いた全ＲＥＰのアミノ酸残基の総数をｔとしたときに、ＧＰＧＸＸモチーフ含有率はｓ／ｔとして算出される。 In the present specification, the “GPGXX motif content” is a value calculated by the following method.
Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side (A) In all REPs included in the sequence excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence, the total number of GPGXX motifs included in the region is tripled (ie, (Corresponding to the total number of G and P in the GPGXX motif) is defined as s, the sequence from the (A) n motif located at the most C-terminal side to the C-terminus of the domain sequence is excluded from the domain sequence, and (A) the n motif The content ratio of GPGXX motif is calculated as s / t, where t is the total number of amino acid residues of all REPs removed.
　ＧＰＧＸＸモチーフ含有率の算出において、「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列」を対象としているのは、「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列」（ＲＥＰに相当する配列）には、フィブロインに特徴的な配列と相関性の低い配列が含まれることがあり、ｍが小さい場合（つまり、ドメイン配列が短い場合）、ＧＰＧＸＸモチーフ含有率の算出結果に影響するので、この影響を排除するためである。なお、ＲＥＰのＣ末端に「ＧＰＧＸＸモチーフ」が位置する場合、「ＸＸ」が例えば「ＡＡ」の場合であっても、「ＧＰＧＸＸモチーフ」として扱う。 In the calculation of the content ratio of the GPGXX motif, “A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” (A) The sequence from the n motif to the C terminus of the domain sequence ”(sequence corresponding to REP) may include a sequence that is not highly correlated with the sequence characteristic of fibroin, and m is small In this case (that is, when the domain sequence is short), the calculation result of the content ratio of the GPGXX motif is affected, so this influence is excluded. When the “GPGXX motif” is located at the C-terminus of REP, even if “XX” is, for example, “AA”, it is treated as “GPGXX motif”.
　図３は、フィブロインのドメイン配列を示す模式図である。図３を参照しながらＧＰＧＸＸモチーフ含有率の算出方法を具体的に説明する。まず、図３に示したフィブロインのドメイン配列（「［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフ」タイプである。）では、全てのＲＥＰが「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列」（図３中、「領域Ａ」で示した配列。）に含まれているため、ｓを算出するためのＧＰＧＸＸモチーフの個数は７であり、ｓは７×３＝２１となる。同様に、全てのＲＥＰが「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列」（図３中、「領域Ａ」で示した配列。）に含まれているため、当該配列から更に（Ａ）ｎモチーフを除いた全ＲＥＰのアミノ酸残基の総数ｔは５０＋４０＋１０＋２０＋３０＝１５０である。次に、ｓをｔで除すことによって、ｓ／ｔ（％）を算出することができ、図３のフィブロインの場合２１／１５０＝１４．０％となる。 FIG. 3 is a schematic diagram showing the domain sequence of fibroin. The calculation method of the content ratio of GPGXX motif will be specifically described with reference to FIG. First, in the fibroin domain sequence shown in FIG. 3 (of “[(A) n motif-REP] m- (A) n motif” type), all REPs are “most C-terminally located ( A) GPGXX for calculating s because it is included in the “sequence excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” (the sequence indicated by “region A” in FIG. 3). The number of motifs is 7, and s is 7 × 3 = 21. Similarly, all REPs are “a sequence located at the most C-terminal side (A) The sequence from the n motif to the C-terminal of the domain sequence is excluded from the domain sequence” (the sequence indicated by “region A” in FIG. 3) )), The total number t of amino acid residues of all REPs excluding (A) the n motif from the sequence is 50 + 40 + 10 + 20 + 30 = 150. Next, s / t (%) can be calculated by dividing s by t. In the case of fibroin in FIG. 3, 21/150 = 14.0%.
　第６の改変フィブロインは、グルタミン残基含有率が９％以下であることが好ましく、７％以下であることがより好ましく、４％以下であることが更に好ましく、０％であることが特に好ましい。 The sixth modified fibroin preferably has a glutamine residue content of 9% or less, more preferably 7% or less, still more preferably 4% or less, and particularly preferably 0%. .
　本明細書において、「グルタミン残基含有率」は、以下の方法により算出される値である。
　式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むフィブロインにおいて、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列（図３の「領域Ａ」に相当する配列。）に含まれる全てのＲＥＰにおいて、その領域に含まれるグルタミン残基の総数をｕとし、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除き、更に（Ａ）ｎモチーフを除いた全ＲＥＰのアミノ酸残基の総数をｔとしたときに、グルタミン残基含有率はｕ／ｔとして算出される。グルタミン残基含有率の算出において、「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列」を対象としている理由は、上述した理由と同様である。 In the present specification, the “glutamine residue content” is a value calculated by the following method.
Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side Located in (A) all REPs included in the sequence (sequence corresponding to “region A” in FIG. 3) excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence (included in that region) The total number of glutamine residues is u, the sequence from the (A) n- motif located at the most C-terminal side to the C-terminus of the domain sequence is removed from the domain sequence, and (A) the amino acid residues of all REPs excluding the n- motif When the total number of groups is t, the glutamine residue content is calculated as u / t. In the calculation of the glutamine residue content rate, the reason why "A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminus of the domain sequence from the domain sequence" is the reason described above. It is the same.
　第６の改変フィブロインは、そのドメイン配列が、天然由来のフィブロインと比較して、ＲＥＰ中の１又は複数のグルタミン残基を欠失したこと、又は他のアミノ酸残基に置換したことに相当するアミノ酸配列を有するものであってよい。 The sixth modified fibroin corresponds to its domain sequence having one or more glutamine residues in REP deleted or replaced with other amino acid residues compared to naturally occurring fibroin. It may have an amino acid sequence.
　「他のアミノ酸残基」は、グルタミン残基以外のアミノ酸残基であればよいが、グルタミン残基よりも疎水性指標の大きいアミノ酸残基であることが好ましい。アミノ酸残基の疎水性指標は表１に示すとおりである。 The “other amino acid residue” may be an amino acid residue other than a glutamine residue, but is preferably an amino acid residue having a larger hydrophobicity index than the glutamine residue. Table 1 shows the hydrophobicity index of amino acid residues.
　表１に示すとおり、グルタミン残基よりも疎水性指標の大きいアミノ酸残基としては、イソロイシン（Ｉ）、バリン（Ｖ）、ロイシン（Ｌ）、フェニルアラニン（Ｆ）、システイン（Ｃ）、メチオニン（Ｍ）アラニン（Ａ）、グリシン（Ｇ）、スレオニン（Ｔ）、セリン（Ｓ）、トリプトファン（Ｗ）、チロシン（Ｙ）、プロリン（Ｐ）及びヒスチジン（Ｈ）から選ばれるアミノ酸残基を挙げることができる。これらの中でも、イソロイシン（Ｉ）、バリン（Ｖ）、ロイシン（Ｌ）、フェニルアラニン（Ｆ）、システイン（Ｃ）、メチオニン（Ｍ）及びアラニン（Ａ）から選ばれるアミノ酸残基であることがより好ましく、イソロイシン（Ｉ）、バリン（Ｖ）、ロイシン（Ｌ）及びフェニルアラニン（Ｆ）から選ばれるアミノ酸残基であることが更に好ましい。 As shown in Table 1, amino acid residues having a larger hydrophobicity index than glutamine residues include isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M ) Amino acid residues selected from alanine (A), glycine (G), threonine (T), serine (S), tryptophan (W), tyrosine (Y), proline (P) and histidine (H). it can. Among these, an amino acid residue selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine (C), methionine (M) and alanine (A) is more preferable. More preferably, it is an amino acid residue selected from isoleucine (I), valine (V), leucine (L) and phenylalanine (F).
　第６の改変フィブロインは、ＲＥＰの疎水性度が、－０．８以上であることが好ましく、－０．７以上であることがより好ましく、０以上であることが更に好ましく、０．３以上であることが更により好ましく、０．４以上であることが特に好ましい。ＲＥＰの疎水性度の上限に特に制限はなく、１．０以下であってよく、０．７以下であってもよい。 In the sixth modified fibroin, the hydrophobicity of REP is preferably −0.8 or more, more preferably −0.7 or more, still more preferably 0 or more, and 0.3 or more. It is still more preferable that it is and it is especially preferable that it is 0.4 or more. There is no restriction | limiting in particular in the upper limit of the hydrophobicity of REP, It may be 1.0 or less and may be 0.7 or less.
　本明細書において、「ＲＥＰの疎水性度」は、以下の方法により算出される値である。
　式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むフィブロインにおいて、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列（図３の「領域Ａ」に相当する配列。）に含まれる全てのＲＥＰにおいて、その領域の各アミノ酸残基の疎水性指標の総和をｖとし、最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除き、更に（Ａ）ｎモチーフを除いた全ＲＥＰのアミノ酸残基の総数をｔとしたときに、ＲＥＰの疎水性度はｖ／ｔとして算出される。ＲＥＰの疎水性度の算出において、「最もＣ末端側に位置する（Ａ）ｎモチーフからドメイン配列のＣ末端までの配列をドメイン配列から除いた配列」を対象としている理由は、上述した理由と同様である。 In the present specification, the “hydrophobicity of REP” is a value calculated by the following method.
Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) In the fibroin containing the domain sequence represented by the n motif, the most C-terminal side (A) In all REPs included in the sequence (sequence corresponding to “region A” in FIG. 3) obtained by removing the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence (each corresponding to “region A” in FIG. 3), each amino acid in the region Let v be the sum of the hydrophobicity indices of the residues, remove the sequence from the (A) n motif located at the most C-terminal side to the C-terminus of the domain sequence from the domain sequence, and (A) all REPs excluding the n motif The hydrophobicity of REP is calculated as v / t, where t is the total number of amino acid residues. In the calculation of the hydrophobicity of REP, the reason why “A sequence located at the most C-terminal side (A) excluding the sequence from the n motif to the C-terminal of the domain sequence from the domain sequence” is the reason described above. It is the same.
　第６の改変フィブロインは、そのドメイン配列が、天然由来のフィブロインと比較して、ＲＥＰ中の１又は複数のグルタミン残基を欠失したこと、及び／又はＲＥＰ中の１又は複数のグルタミン残基を他のアミノ酸残基に置換したことに相当する改変に加え、更に１又は複数のアミノ酸残基を置換、欠失、挿入及び／又は付加したことに相当するアミノ酸配列の改変があってもよい。 The sixth modified fibroin has its domain sequence deleted one or more glutamine residues in REP and / or one or more glutamine residues in REP compared to naturally occurring fibroin. In addition to modifications corresponding to substitution of other amino acid residues, there may also be amino acid sequence modifications corresponding to substitution, deletion, insertion and / or addition of one or more amino acid residues. .
　第６の改変フィブロインは、例えば、クローニングした天然由来のフィブロインの遺伝子配列からＲＥＰ中の１又は複数のグルタミン残基を欠失させること、及び／又はＲＥＰ中の１又は複数のグルタミン残基を他のアミノ酸残基に置換することにより得ることができる。また、例えば、天然由来のフィブロインのアミノ酸配列からＲＥＰ中の１又は複数のグルタミン残基を欠失したこと、及び／又はＲＥＰ中の１又は複数のグルタミン残基を他のアミノ酸残基に置換したことに相当するアミノ酸配列を設計し、設計したアミノ酸配列をコードする核酸を化学合成することにより得ることもできる。 The sixth modified fibroin is, for example, deleting one or more glutamine residues in REP from the cloned gene sequence of naturally occurring fibroin and / or other one or more glutamine residues in REP. It can obtain by substituting to the amino acid residue. In addition, for example, one or more glutamine residues in REP are deleted from the amino acid sequence of naturally occurring fibroin, and / or one or more glutamine residues in REP are replaced with other amino acid residues. In particular, it can also be obtained by designing a corresponding amino acid sequence and chemically synthesizing a nucleic acid encoding the designed amino acid sequence.
　第６の改変フィブロインのより具体的な例として、（６－ｉ）配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２若しくは配列番号３３で示されるアミノ酸配列を含む、改変フィブロイン、又は（６－ｉｉ）配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２若しくは配列番号３３で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As a more specific example of the sixth modified fibroin, (6-i) the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33 Or (6-ii) the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33 and 90% or more of the sequence Mention may be made of modified fibroin comprising amino acid sequences having identity.
　（６－ｉ）の改変フィブロインについて説明する。 The (6-i) modified fibroin will be described.
　配列番号７で示されるアミノ酸配列（Ｍｅｔ－ＰＲＴ４１０）は、天然由来のフィブロインであるＮｅｐｈｉｌａ　ｃｌａｖｉｐｅｓ（ＧｅｎＢａｎｋアクセッション番号：Ｐ４６８０４．１、ＧＩ：１１７４４１５）の塩基配列及びアミノ酸配列に基づき、（Ａ）ｎモチーフ中のアラニン残基が連続するアミノ酸配列をアラニン残基が連続する数を５つにする等の生産性を向上させるためのアミノ酸の改変を行ったものである。一方、Ｍｅｔ－ＰＲＴ４１０は、グルタミン残基（Ｑ）の改変は行っていないため、グルタミン残基含有率は、天然由来のフィブロインのグルタミン残基含有率と同程度である。 The amino acid sequence shown in SEQ ID NO: 7 (Met-PRT410) is based on the base sequence and amino acid sequence of Nephila clapes (GenBank accession numbers: P46804.1, GI: 1174415), which is a naturally occurring fibroin, based on (A) n The amino acid sequence in which the alanine residue in the motif is continued is modified with an amino acid to improve productivity, such as the number of consecutive alanine residues is five. On the other hand, since Met-PRT410 has not altered the glutamine residue (Q), the glutamine residue content is comparable to the glutamine residue content of naturally occurring fibroin.
　配列番号２７で示されるアミノ酸配列（Ｍ＿ＰＲＴ８８８）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）中のＱＱを全てＶＬに置換したものである。 The amino acid sequence (M_PRT888) represented by SEQ ID NO: 27 is obtained by replacing all QQs in Met-PRT410 (SEQ ID NO: 7) with VL.
　配列番号２８で示されるアミノ酸配列（Ｍ＿ＰＲＴ９６５）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）中のＱＱを全てＴＳに置換し、かつ残りのＱをＡに置換したものである。 The amino acid sequence represented by SEQ ID NO: 28 (M_PRT965) is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with TS and replacing the remaining Q with A.
　配列番号２９で示されるアミノ酸配列（Ｍ＿ＰＲＴ８８９）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）中のＱＱを全てＶＬに置換し、かつ残りのＱをＩに置換したものである。 The amino acid sequence (M_PRT889) shown in SEQ ID NO: 29 is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with VL and replacing the remaining Q with I.
　配列番号３０で示されるアミノ酸配列（Ｍ＿ＰＲＴ９１６）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）中のＱＱを全てＶＩに置換し、かつ残りのＱをＬに置換したものである。 The amino acid sequence represented by SEQ ID NO: 30 (M_PRT916) is obtained by substituting all QQs in Met-PRT410 (SEQ ID NO: 7) with VI and replacing the remaining Q with L.
　配列番号３１で示されるアミノ酸配列（Ｍ＿ＰＲＴ９１８）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）中のＱＱを全てＶＦに置換し、かつ残りのＱをＩに置換したものである。 The amino acid sequence (M_PRT918) represented by SEQ ID NO: 31 is obtained by replacing all QQs in Met-PRT410 (SEQ ID NO: 7) with VF and replacing the remaining Q with I.
　配列番号３４で示されるアミノ酸配列（Ｍ＿ＰＲＴ５２５）は、Ｍｅｔ－ＰＲＴ４１０（配列番号７）に対し、アラニン残基が連続する領域（Ａ５）に２つのアラニン残基を挿入し、Ｍｅｔ－ＰＲＴ４１０の分子量とほぼ同じになるよう、Ｃ末端側のドメイン配列２つを欠失させ、かつグルタミン残基（Ｑ）１３箇所をセリン残基（Ｓ）又はプロリン残基（Ｐ）に置換したものである。 The amino acid sequence represented by SEQ ID NO: 34 (M_PRT525) is obtained by inserting two alanine residues into a region (A5) where alanine residues are continuous with respect to Met-PRT410 (SEQ ID NO: 7), and the molecular weight of Met-PRT410. Two domain sequences on the C-terminal side were deleted and 13 glutamine residues (Q) were substituted with serine residues (S) or proline residues (P) so that they were almost the same.
　配列番号３２で示されるアミノ酸配列（Ｍ＿ＰＲＴ６９９）は、Ｍ＿ＰＲＴ５２５（配列番号３４）中のＱＱを全てＶＬに置換したものである。 The amino acid sequence (M_PRT699) represented by SEQ ID NO: 32 is obtained by substituting VL for all QQs in M_PRT525 (SEQ ID NO: 34).
　配列番号３３で示されるアミノ酸配列（Ｍ＿ＰＲＴ６９８）は、Ｍ＿ＰＲＴ５２５（配列番号３４）中のＱＱを全てＶＬに置換し、かつ残りのＱをＩに置換したものである。 The amino acid sequence (M_PRT698) represented by SEQ ID NO: 33 is obtained by substituting all QQs in M_PRT525 (SEQ ID NO: 34) with VL and replacing the remaining Q with I.
　配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２及び配列番号３３で示されるアミノ酸配列は、いずれもグルタミン残基含有率は９％以下である（表２）。 The amino acid sequences represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33 all have a glutamine residue content of 9% or less (Table 2). ).
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　（６－ｉ）の改変フィブロインは、配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２又は配列番号３３で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin (6-i) may be composed of the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33. .
　（６－ｉｉ）の改変フィブロインは、配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２又は配列番号３３で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（６－ｉｉ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin of (6-ii) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33 The amino acid sequence having The modified fibroin of (6-ii) is also represented by the formula 1: [(A) n motif-REP] m or the formula 2: [(A) n motif-REP] m- (A) n motif. A protein containing a sequence. The sequence identity is preferably 95% or more.
　（６－ｉｉ）の改変フィブロインは、グルタミン残基含有率が９％以下であることが好ましい。また、（６－ｉｉ）の改変フィブロインは、ＧＰＧＸＸモチーフ含有率が１０％以上であることが好ましい。 The modified fibroin (6-ii) preferably has a glutamine residue content of 9% or less. The modified fibroin (6-ii) preferably has a GPGXX motif content of 10% or more.
　第６の改変フィブロインは、Ｎ末端及びＣ末端のいずれか一方又は両方にタグ配列を含んでいてもよい。これにより、改変フィブロインの単離、固定化、検出及び可視化等が可能となる。 The sixth modified fibroin may contain a tag sequence at one or both of the N-terminal and C-terminal. This makes it possible to isolate, immobilize, detect and visualize the modified fibroin.
　タグ配列を含む第６の改変フィブロインのより具体的な例として、（６－ｉｉｉ）配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０若しくは配列番号４１で示されるアミノ酸配列を含む、改変フィブロイン、又は（６－ｉｖ）配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０若しくは配列番号４１で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含む、改変フィブロインを挙げることができる。 As more specific examples of the sixth modified fibroin containing the tag sequence, (6-iii) SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41 A modified fibroin comprising the amino acid sequence shown or (6-iv) SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41 and 90 Mention may be made of modified fibroin comprising an amino acid sequence having a sequence identity of at least%.
　配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０及び配列番号４１で示されるアミノ酸配列は、それぞれ配列番号２７、配列番号２８、配列番号２９、配列番号３０、配列番号３１、配列番号３２及び配列番号３３で示されるアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（Ｈｉｓタグ配列及びヒンジ配列を含む）を付加したものである。Ｎ末端にタグ配列を付加しただけであるため、グルタミン残基含有率に変化はなく、配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０及び配列番号４１で示されるアミノ酸配列は、いずれもグルタミン残基含有率が９％以下である（表３）。 The amino acid sequences represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, and SEQ ID NO: 41 are SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, respectively. The amino acid sequence represented by SEQ ID NO: 12 (including His tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence represented by SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33. Since only the tag sequence was added to the N-terminus, there was no change in glutamine residue content, and SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, and SEQ ID NO: 41. The glutamine residue content is 9% or less in any of the amino acid sequences indicated by (Table 3).
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　（６－ｉｉｉ）の改変フィブロインは、配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０又は配列番号４１で示されるアミノ酸配列からなるものであってもよい。 The modified fibroin of (6-iii) may be composed of the amino acid sequence represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, or SEQ ID NO: 41. .
　（６－ｉｖ）の改変フィブロインは、配列番号３５、配列番号３６、配列番号３７、配列番号３８、配列番号３９、配列番号４０又は配列番号４１で示されるアミノ酸配列と９０％以上の配列同一性を有するアミノ酸配列を含むものである。（６－ｉｖ）の改変フィブロインもまた、式１：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ、又は式２：［（Ａ）ｎモチーフ－ＲＥＰ］ｍ－（Ａ）ｎモチーフで表されるドメイン配列を含むタンパク質である。上記配列同一性は、９５％以上であることが好ましい。 The modified fibroin of (6-iv) has a sequence identity of 90% or more with the amino acid sequence represented by SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40 or SEQ ID NO: 41. The amino acid sequence having The modified fibroin of (6-iv) is also a domain represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m- (A) n motif. A protein containing a sequence. The sequence identity is preferably 95% or more.
　（６－ｉｖ）の改変フィブロインは、グルタミン残基含有率が９％以下であることが好ましい。また、（６－ｉｖ）の改変フィブロインは、ＧＰＧＸＸモチーフ含有率が１０％以上であることが好ましい。 The modified fibroin (6-iv) preferably has a glutamine residue content of 9% or less. The modified fibroin (6-iv) preferably has a GPGXX motif content of 10% or more.
　第６の改変フィブロインは、組換えタンパク質生産系において生産されたタンパク質を宿主の外部に放出するための分泌シグナルを含んでいてもよい。分泌シグナルの配列は、宿主の種類に応じて適宜設定することができる。 The sixth modified fibroin may contain a secretion signal for releasing the protein produced in the recombinant protein production system to the outside of the host. The sequence of the secretion signal can be appropriately set according to the type of host.
　本実施形態に係る改変フィブロインは、第１の改変フィブロイン、第２の改変フィブロイン、第３の改変フィブロイン、第４の改変フィブロイン、第５の改変フィブロイン、及び第６の改変フィブロインが有する特徴のうち、少なくとも２つ以上の特徴を併せ持つ改変フィブロインであってもよい。 The modified fibroin according to the present embodiment is characterized in that the first modified fibroin, the second modified fibroin, the third modified fibroin, the fourth modified fibroin, the fifth modified fibroin, and the sixth modified fibroin Alternatively, it may be a modified fibroin having at least two or more characteristics.
　コラーゲン由来のタンパク質として、例えば、式３：［ＲＥＰ２］ｐで表されるドメイン配列を含むタンパク質（ここで、式３中、ｐは５～３００の整数を示す。ＲＥＰ２は、Ｇｌｙ－Ｘ－Ｙから構成されるアミノ酸配列を示し、Ｘ及びＹはＧｌｙ以外の任意のアミノ酸残基を示す。複数存在するＲＥＰ２は、互いに同一のアミノ酸配列でもよく、異なるアミノ酸配列でもよい。）を挙げることができる。具体的には、配列番号４２で示されるアミノ酸配列を含むタンパク質を挙げることができる。配列番号４２で示されるアミノ酸配列は、ＮＣＢＩデータベースから入手したヒトのコラーゲンタイプ４の部分的な配列（ＮＣＢＩのＧｅｎＢａｎｋのアクセッション番号：ＣＡＡ５６３３５．１、ＧＩ：３７０２４５２）のリピート部分及びモチーフに該当する３０１残基目から５４０残基目までのアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（タグ配列及びヒンジ配列）が付加されたものである。 As a protein derived from collagen, for example, a protein comprising a domain sequence represented by Formula 3: [REP2] p (wherein, in Formula 3, p represents an integer of 5 to 300. REP2 represents Gly-XY. And X and Y represent any amino acid residue other than Gly. Plural REP2s may be the same amino acid sequence or different amino acid sequences. . Specific examples include a protein containing the amino acid sequence represented by SEQ ID NO: 42. The amino acid sequence shown in SEQ ID NO: 42 corresponds to the repeat portion and motif of the partial sequence of human collagen type 4 (NCBI GenBank accession number: CAA56335.1, GI: 3702452) obtained from the NCBI database. An amino acid sequence represented by SEQ ID NO: 12 (tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence from the 301st residue to the 540th residue.
　レシリン由来のタンパク質として、例えば、式４：［ＲＥＰ３］ｑで表されるドメイン配列を含むタンパク質（ここで、式４中、ｑは４～３００の整数を示す。ＲＥＰ３はＳｅｒ－Ｊ－Ｊ－Ｔｙｒ－Ｇｌｙ－Ｕ－Ｐｒｏから構成されるアミノ酸配列を示す。Ｊは任意アミノ酸残基を示し、特にＡｓｐ、Ｓｅｒ及びＴｈｒからなる群から選ばれるアミノ酸残基であることが好ましい。Ｕは任意のアミノ酸残基を示し、特にＰｒｏ、Ａｌａ、Ｔｈｒ及びＳｅｒからなる群から選ばれるアミノ酸残基であることが好ましい。複数存在するＲＥＰ４は、互いに同一のアミノ酸配列でもよく、異なるアミノ酸配列でもよい。）を挙げることができる。具体的には、配列番号４３で示されるアミノ酸配列を含むタンパク質を挙げることができる。配列番号４３で示されるアミノ酸配列は、レシリン（ＮＣＢＩのＧｅｎＢａｎｋのアクセッション番号ＮＰ　６１１１５７、Ｇｌ：２４６５４２４３）のアミノ酸配列において、８７残基目のＴｈｒをＳｅｒに置換し、かつ９５残基目のＡｓｎをＡｓｐに置換した配列の１９残基目から３２１残基目までのアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（タグ配列及びヒンジ配列）が付加されたものである。 As a protein derived from resilin, for example, a protein comprising a domain sequence represented by Formula 4: [REP3] q (wherein q represents an integer of 4 to 300. REP3 represents Ser-JJ- An amino acid sequence composed of Tyr-Gly-U-Pro, wherein J represents an arbitrary amino acid residue, and is particularly preferably an amino acid residue selected from the group consisting of Asp, Ser, and Thr. An amino acid residue, particularly an amino acid residue selected from the group consisting of Pro, Ala, Thr and Ser. A plurality of REP4 may be the same or different from each other.) Can be mentioned. Specifically, a protein containing the amino acid sequence represented by SEQ ID NO: 43 can be exemplified. The amino acid sequence represented by SEQ ID NO: 43 is the amino acid sequence of resilin (NCBI GenBank accession number NP 611157, Gl: 24654243), wherein Thr at the 87th residue is replaced with Ser, and the Asn at the 95th residue. The amino acid sequence represented by SEQ ID NO: 12 (tag sequence and hinge sequence) is added to the N-terminus of the amino acid sequence from the 19th residue to the 321st residue of the sequence in which is replaced with Asp.
　エラスチン由来のタンパク質として、例えば、ＮＣＢＩのＧｅｎＢａｎｋのアクセッション番号ＡＡＣ９８３９５（ヒト）、Ｉ４７０７６（ヒツジ）、ＮＰ７８６９６６（ウシ）等のアミノ酸配列を有するタンパク質を挙げることができる。具体的には、配列番号４４で示されるアミノ酸配列を含むタンパク質を挙げることができる。配列番号４４で示されるアミノ酸配列は、ＮＣＢＩのＧｅｎＢａｎｋのアクセッション番号ＡＡＣ９８３９５のアミノ酸配列の１２１残基目から３９０残基目までのアミノ酸配列のＮ末端に配列番号１２で示されるアミノ酸配列（タグ配列及びヒンジ配列）が付加されたものである。 Examples of the elastin-derived protein include proteins having amino acid sequences such as NCBI GenBank accession numbers AAC98395 (human), I47076 (sheep), and NP786966 (bovine). Specifically, a protein containing the amino acid sequence represented by SEQ ID NO: 44 can be exemplified. The amino acid sequence represented by SEQ ID NO: 44 is the amino acid sequence represented by SEQ ID NO: 12 at the N-terminus of the amino acid sequence of residues 121 to 390 of the amino acid sequence of NCBI GenBank accession number AAC98395 (tag sequence). And a hinge arrangement).
　ケラチン由来のタンパク質として、例えば、カプラ・ヒルクス（Ｃａｐｒａ　ｈｉｒｃｕｓ）のタイプＩケラチン等を挙げることができる。具体的には、配列番号４５で示されるアミノ酸配列（ＮＣＢＩのＧｅｎＢａｎｋのアクセッション番号ＡＣＹ３０４６６のアミノ酸配列）を含むタンパク質を挙げることができる。 Examples of keratin-derived proteins include Capra hircus type I keratin. Specifically, a protein containing the amino acid sequence represented by SEQ ID NO: 45 (amino acid sequence of NCBI GenBank accession number ACY30466) can be exemplified.
　上述した構造タンパク質及び当該構造タンパク質に由来する改変構造タンパク質は、１種を単独で、又は２種以上を組み合わせて用いることができる。 The above-mentioned structural protein and the modified structural protein derived from the structural protein can be used singly or in combination of two or more.
（タンパク質の製造方法）
　タンパク質は、例えば、当該タンパク質をコードする核酸配列と、当該核酸配列に作動可能に連結された１又は複数の調節配列とを有する発現ベクターで形質転換された宿主により、当該核酸を発現させることにより生産することができる。 (Protein production method)
A protein can be expressed, for example, by expressing the nucleic acid in a host transformed with an expression vector having a nucleic acid sequence encoding the protein and one or more regulatory sequences operably linked to the nucleic acid sequence. Can be produced.
　タンパク質をコードする核酸の製造方法は、特に制限されない。例えば、天然のフィブロイン等のタンパク質をコードする遺伝子を利用して、ポリメラーゼ連鎖反応（ＰＣＲ）などで増幅しクローニングし、必要に応じて遺伝子工学的手法により改変する方法、又は、化学的に合成する方法によって、当該核酸を製造することができる。核酸の化学的な合成方法も特に制限されず、例えば、ＮＣＢＩのウェブデータベースなどより入手したタンパク質のアミノ酸配列情報をもとに、ＡＫＴＡ　ｏｌｉｇｏｐｉｌｏｔ　ｐｌｕｓ　１０／１００（ＧＥヘルスケア・ジャパン株式会社）などで自動合成したオリゴヌクレオチドをＰＣＲなどで連結する方法によって遺伝子を化学的に合成することができる。この際に、タンパク質の精製及び／又は確認を容易にするため、上記のアミノ酸配列のＮ末端に開始コドン及びＨｉｓ１０タグからなるアミノ酸配列を付加したアミノ酸配列からなるタンパク質をコードする核酸を合成してもよい。 The method for producing a nucleic acid encoding a protein is not particularly limited. For example, a gene encoding a protein such as natural fibroin is amplified and cloned by polymerase chain reaction (PCR) or the like, and if necessary, modified by genetic engineering techniques, or chemically synthesized The nucleic acid can be produced by the method. The method for chemically synthesizing nucleic acids is not particularly limited. For example, AKTA oligopilot plus 10/100 (GE Healthcare Japan Co., Ltd.) is used based on the amino acid sequence information of proteins obtained from the NCBI web database. A gene can be chemically synthesized by a method of linking oligonucleotides that are synthesized automatically by PCR or the like. At this time, in order to facilitate the purification and / or confirmation of the protein, a nucleic acid encoding a protein consisting of an amino acid sequence in which an amino acid sequence consisting of a start codon and a His10 tag is added to the N terminus of the above amino acid sequence is synthesized. Also good.
　調節配列は、宿主におけるタンパク質の発現を制御する配列（例えば、プロモーター、エンハンサー、リボソーム結合配列、転写終結配列等）であり、宿主の種類に応じて適宜選択することができる。プロモーターとして、宿主細胞中で機能し、タンパク質を発現誘導可能な誘導性プロモーターを用いてもよい。誘導性プロモーターは、誘導物質（発現誘導剤）の存在、リプレッサー分子の非存在、又は温度、浸透圧若しくはｐＨ値の上昇若しくは低下等の物理的要因により、転写を制御できるプロモーターである。 Regulatory sequences are sequences that control the expression of proteins in the host (for example, promoters, enhancers, ribosome binding sequences, transcription termination sequences, etc.), and can be appropriately selected depending on the type of host. As the promoter, an inducible promoter that functions in a host cell and can induce protein expression may be used. An inducible promoter is a promoter that can control transcription by the presence of an inducer (expression inducer), absence of a repressor molecule, or physical factors such as an increase or decrease in temperature, osmotic pressure or pH value.
　発現ベクターの種類は、プラスミドベクター、ウイルスベクター、コスミドベクター、フォスミドベクター、人工染色体ベクター等、宿主の種類に応じて適宜選択することができる。発現ベクターとしては、宿主細胞において自立複製が可能、又は宿主の染色体中への組込みが可能で、タンパク質をコードする核酸を転写できる位置にプロモーターを含有しているものが好適に用いられる。 The type of expression vector can be appropriately selected according to the type of host, such as a plasmid vector, virus vector, cosmid vector, fosmid vector, artificial chromosome vector, and the like. As the expression vector, a vector which can replicate autonomously in a host cell or can be integrated into a host chromosome and contains a promoter at a position where a nucleic acid encoding a protein can be transcribed is preferably used.
　宿主として、原核生物、並びに酵母、糸状真菌、昆虫細胞、動物細胞及び植物細胞等の真核生物のいずれも好適に用いることができる。 As the host, any of prokaryotes and eukaryotes such as yeast, filamentous fungi, insect cells, animal cells and plant cells can be preferably used.
　原核生物の宿主の好ましい例として、エシェリヒア属、ブレビバチルス属、セラチア属、バチルス属、ミクロバクテリウム属、ブレビバクテリウム属、コリネバクテリウム属及びシュードモナス属等に属する細菌を挙げることができる。エシェリヒア属に属する微生物として、例えば、エシェリヒア・コリ等を挙げることができる。ブレビバチルス属に属する微生物として、例えば、ブレビバチルス・アグリ等を挙げることができる。セラチア属に属する微生物として、例えば、セラチア・リクエファシエンス等を挙げることができる。バチルス属に属する微生物として、例えば、バチルス・サチラス等を挙げることができる。ミクロバクテリウム属に属する微生物として、例えば、ミクロバクテリウム・アンモニアフィラム等を挙げることができる。ブレビバクテリウム属に属する微生物として、例えば、ブレビバクテリウム・ディバリカタム等を挙げることができる。コリネバクテリウム属に属する微生物として、例えば、コリネバクテリウム・アンモニアゲネス等を挙げることができる。シュードモナス（Ｐｓｅｕｄｏｍｏｎａｓ）属に属する微生物として、例えば、シュードモナス・プチダ等を挙げることができる。 Preferred examples of prokaryotic hosts include bacteria belonging to the genus Escherichia, Brevibacillus, Serratia, Bacillus, Microbacterium, Brevibacterium, Corynebacterium, Pseudomonas and the like. Examples of microorganisms belonging to the genus Escherichia include Escherichia coli. Examples of microorganisms belonging to the genus Brevibacillus include Brevibacillus agri and the like. Examples of microorganisms belonging to the genus Serratia include Serratia liqufaciens and the like. Examples of microorganisms belonging to the genus Bacillus include Bacillus subtilis. Examples of microorganisms belonging to the genus Microbacterium include microbacterium / ammonia film. Examples of microorganisms belonging to the genus Brevibacterium include Brevibacterium divaricatam. Examples of microorganisms belonging to the genus Corynebacterium include Corynebacterium ammoniagenes. Examples of microorganisms belonging to the genus Pseudomonas include Pseudomonas putida.
　原核生物を宿主とする場合、タンパク質をコードする核酸を導入するベクターとしては、例えば、ｐＢＴｒｐ２（ベーリンガーマンハイム社製）、ｐＧＥＸ（Ｐｈａｒｍａｃｉａ社製）、ｐＵＣ１８、ｐＢｌｕｅｓｃｒｉｐｔＩＩ、ｐＳｕｐｅｘ、ｐＥＴ２２ｂ、ｐＣｏｌｄ、ｐＵＢ１１０、ｐＮＣＯ２（特開２００２－２３８５６９号公報）等を挙げることができる。 When a prokaryote is used as a host, examples of a vector for introducing a nucleic acid encoding a protein include pBTrp2 (manufactured by Boehringer Mannheim), pGEX (manufactured by Pharmacia), pUC18, pBluescriptII, pSupex, pET22b, pCold, pUB110, pNCO2 (Japanese Patent Laid-Open No. 2002-238696) and the like.
　真核生物の宿主としては、例えば、酵母及び糸状真菌（カビ等）を挙げることができる。酵母としては、例えば、サッカロマイセス属、ピキア属、シゾサッカロマイセス属等に属する酵母を挙げることができる。糸状真菌としては、例えば、アスペルギルス属、ペニシリウム属、トリコデルマ（Ｔｒｉｃｈｏｄｅｒｍａ）属等に属する糸状真菌を挙げることができる。 Examples of eukaryotic hosts include yeast and filamentous fungi (molds, etc.). Examples of the yeast include yeasts belonging to the genus Saccharomyces, Pichia, Schizosaccharomyces and the like. Examples of the filamentous fungi include filamentous fungi belonging to the genus Aspergillus, the genus Penicillium, the genus Trichoderma and the like.
　真核生物を宿主とする場合、タンパク質をコードする核酸を導入するベクターとしては、例えば、ＹＥｐ１３（ＡＴＣＣ３７１１５）、ＹＥｐ２４（ＡＴＣＣ３７０５１）等を挙げることができる。上記宿主細胞への発現ベクターの導入方法としては、上記宿主細胞へＤＮＡを導入する方法であればいずれも用いることができる。例えば、カルシウムイオンを用いる方法〔Ｐｒｏｃ．　Ｎａｔｌ．　Ａｃａｄ．　Ｓｃｉ．　ＵＳＡ，６９，２１１０（１９７２）〕、エレクトロポレーション法、スフェロプラスト法、プロトプラスト法、酢酸リチウム法、コンピテント法等を挙げることができる。 When a eukaryote is used as a host, examples of a vector into which a nucleic acid encoding a protein is introduced include YEp13 (ATCC37115) and YEp24 (ATCC37051). As a method for introducing the expression vector into the host cell, any method can be used as long as it is a method for introducing DNA into the host cell. For example, a method using calcium ions [Proc. Natl. Acad. Sci. USA, 69, 2110 (1972)], electroporation method, spheroplast method, protoplast method, lithium acetate method, competent method, and the like.
　発現ベクターで形質転換された宿主による核酸の発現方法としては、直接発現のほか、モレキュラー・クローニング第２版に記載されている方法等に準じて、分泌生産、融合タンパク質発現等を行うことができる。 As a method for expressing a nucleic acid by a host transformed with an expression vector, in addition to direct expression, secretory production, fusion protein expression, etc. can be performed according to the method described in Molecular Cloning 2nd edition, etc. .
　タンパク質は、例えば、発現ベクターで形質転換された宿主を培養培地中で培養し、培養培地中に当該タンパク質を生成蓄積させ、該培養培地から採取することにより製造することができる。宿主を培養培地中で培養する方法は、宿主の培養に通常用いられる方法に従って行うことができる。 The protein can be produced, for example, by culturing a host transformed with an expression vector in a culture medium, producing and accumulating the protein in the culture medium, and collecting the protein from the culture medium. The method for culturing a host in a culture medium can be performed according to a method usually used for culturing a host.
　宿主が、大腸菌等の原核生物又は酵母等の真核生物である場合、培養培地として、宿主が資化し得る炭素源、窒素源及び無機塩類等を含有し、宿主の培養を効率的に行える培地であれば天然培地、合成培地のいずれを用いてもよい。 When the host is a prokaryotic organism such as Escherichia coli or a eukaryotic organism such as yeast, the culture medium contains a carbon source, nitrogen source, inorganic salts, etc. that can be assimilated by the host, and can efficiently culture the host. If so, either a natural medium or a synthetic medium may be used.
　炭素源としては、上記形質転換微生物が資化し得るものであればよく、例えば、グルコース、フラクトース、スクロース、及びこれらを含有する糖蜜、デンプン及びデンプン加水分解物等の炭水化物、酢酸及びプロピオン酸等の有機酸、並びにエタノール及びプロパノール等のアルコール類を用いることができる。窒素源としては、例えば、アンモニア、塩化アンモニウム、硫酸アンモニウム、酢酸アンモニウム及びリン酸アンモニウム等の無機酸又は有機酸のアンモニウム塩、その他の含窒素化合物、並びにペプトン、肉エキス、酵母エキス、コーンスチープリカー、カゼイン加水分解物、大豆粕及び大豆粕加水分解物、各種発酵菌体及びその消化物を用いることができる。無機塩類としては、例えば、リン酸第一カリウム、リン酸第二カリウム、リン酸マグネシウム、硫酸マグネシウム、塩化ナトリウム、硫酸第一鉄、硫酸マンガン、硫酸銅及び炭酸カルシウムを用いることができる。 Any carbon source may be used as long as it can be assimilated by the above-mentioned transformed microorganism. Examples thereof include glucose, fructose, sucrose, and carbohydrates such as molasses, starch and starch hydrolyzate, acetic acid and propionic acid, etc. Organic acids and alcohols such as ethanol and propanol can be used. Examples of the nitrogen source include ammonium salts of inorganic acids or organic acids such as ammonia, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium phosphate, other nitrogen-containing compounds, and peptone, meat extract, yeast extract, corn steep liquor, Casein hydrolyzate, soybean meal and soybean meal hydrolyzate, various fermented cells and digested products thereof can be used. As inorganic salts, for example, monopotassium phosphate, dipotassium phosphate, magnesium phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate and calcium carbonate can be used.
　大腸菌等の原核生物又は酵母等の真核生物の培養は、例えば、振盪培養又は深部通気攪拌培養等の好気的条件下で行うことができる。培養温度は、例えば、１５～４０℃である。培養時間は、通常１６時間～７日間である。培養中の培養培地のｐＨは３．０～９．０に保持することが好ましい。培養培地のｐＨの調整は、無機酸、有機酸、アルカリ溶液、尿素、炭酸カルシウム及びアンモニア等を用いて行うことができる。 Cultivation of prokaryotes such as E. coli or eukaryotes such as yeast can be performed under aerobic conditions such as shaking culture or deep aeration and agitation culture. The culture temperature is, for example, 15 to 40 ° C. The culture time is usually 16 hours to 7 days. The pH of the culture medium during the culture is preferably maintained at 3.0 to 9.0. The pH of the culture medium can be adjusted using an inorganic acid, an organic acid, an alkaline solution, urea, calcium carbonate, ammonia, or the like.
　また、培養中、必要に応じて、アンピシリン及びテトラサイクリン等の抗生物質を培養培地に添加してもよい。プロモーターとして誘導性のプロモーターを用いた発現ベクターで形質転換した微生物を培養するときには、必要に応じてインデューサーを培地に添加してもよい。例えば、ｌａｃプロモーターを用いた発現ベクターで形質転換した微生物を培養するときにはイソプロピル－β－Ｄ－チオガラクトピラノシド等を、ｔｒｐプロモーターを用いた発現ベクターで形質転換した微生物を培養するときにはインドールアクリル酸等を培地に添加してもよい。 Moreover, during the culture, antibiotics such as ampicillin and tetracycline may be added to the culture medium as necessary. When culturing a microorganism transformed with an expression vector using an inducible promoter as a promoter, an inducer may be added to the medium as necessary. For example, isopropyl-β-D-thiogalactopyranoside is used when cultivating a microorganism transformed with an expression vector using the lac promoter, and indole acrylic is used when culturing a microorganism transformed with an expression vector using the trp promoter. An acid or the like may be added to the medium.
　発現させたタンパク質の単離、精製は通常用いられている方法で行うことができる。例えば、当該タンパク質が、細胞内に溶解状態で発現した場合には、培養終了後、宿主細胞を遠心分離により回収し、水系緩衝液に懸濁した後、超音波破砕機、フレンチプレス、マントンガウリンホモゲナイザー及びダイノミル等により宿主細胞を破砕し、無細胞抽出液を得る。該無細胞抽出液を遠心分離することにより得られる上清から、タンパク質の単離精製に通常用いられている方法、すなわち、溶媒抽出法、硫安等による塩析法、脱塩法、有機溶媒による沈殿法、ジエチルアミノエチル（ＤＥＡＥ）－セファロース、ＤＩＡＩＯＮ　ＨＰＡ－７５（三菱化成社製）等のレジンを用いた陰イオン交換クロマトグラフィー法、Ｓ－Ｓｅｐｈａｒｏｓｅ　ＦＦ（Ｐｈａｒｍａｃｉａ社製）等のレジンを用いた陽イオン交換クロマトグラフィー法、ブチルセファロース、フェニルセファロース等のレジンを用いた疎水性クロマトグラフィー法、分子篩を用いたゲルろ過法、アフィニティークロマトグラフィー法、クロマトフォーカシング法、等電点電気泳動等の電気泳動法等の方法を単独又は組み合わせて使用し、精製標品を得ることができる。 Isolation and purification of the expressed protein can be performed by a commonly used method. For example, when the protein is expressed in a dissolved state in the cell, the host cell is recovered by centrifugation after culturing, suspended in an aqueous buffer, and then subjected to an ultrasonic crusher, a French press, a Manton Gaurin. The host cells are disrupted with a homogenizer, dynomill, or the like to obtain a cell-free extract. From the supernatant obtained by centrifuging the cell-free extract, a method usually used for protein isolation and purification, that is, a solvent extraction method, a salting-out method using ammonium sulfate, a desalting method, an organic solvent, etc. Precipitation method, anion exchange chromatography method using a resin such as diethylaminoethyl (DEAE) -Sepharose, DIAION HPA-75 (manufactured by Mitsubishi Kasei), and a positive using a resin such as S-Sepharose FF (manufactured by Pharmacia) Electrophoretic methods such as ion exchange chromatography, hydrophobic chromatography using resins such as butyl sepharose and phenyl sepharose, gel filtration using molecular sieve, affinity chromatography, chromatofocusing, isoelectric focusing Using methods such as these alone or in combination, purification It is possible to obtain the goods.
　また、タンパク質が細胞内に不溶体を形成して発現した場合は、同様に宿主細胞を回収後、破砕し、遠心分離を行うことにより、沈殿画分としてタンパク質の不溶体を回収する。回収したタンパク質の不溶体は、タンパク質変性剤で可溶化することができる。該操作の後、上記と同様の単離精製法によりタンパク質の精製標品を得ることができる。当該タンパク質が細胞外に分泌された場合には、培養上清から当該タンパク質を回収することができる。すなわち、培養物を遠心分離等の手法により処理することにより培養上清を取得し、その培養上清から、上記と同様の単離精製法を用いることにより、精製標品を得ることができる。 In addition, when the protein is expressed by forming an insoluble substance in the cell, the host cell is similarly collected and then crushed and centrifuged to collect the protein insoluble substance as a precipitate fraction. The recovered protein insoluble matter can be solubilized with a protein denaturant. After the operation, a purified protein preparation can be obtained by the same isolation and purification method as described above. When the protein is secreted extracellularly, the protein can be recovered from the culture supernatant. That is, a culture supernatant is obtained by treating the culture with a technique such as centrifugation, and a purified preparation can be obtained from the culture supernatant by using the same isolation and purification method as described above.
（タンパク質組成物）
　本実施形態に係るタンパク質組成物は、修飾ヒドロキシル基含有ポリマーと、タンパク質とを少なくとも含むものである。 (Protein composition)
The protein composition according to the present embodiment includes at least a modified hydroxyl group-containing polymer and a protein.
　本実施形態に係るタンパク質組成物は、修飾ヒドロキシル基含有ポリマーとタンパク質が水素結合していることが好ましい。これにより、タンパク質組成物の機能性がより向上する。水素結合は、例えば、修飾ヒドロキシル基含有ポリマー中の官能基（例えば、ヒドロキシル基、機能性官能基又は結合性官能基中の官能基等であってよい。）と、タンパク質中の官能基（例えば、アミノ基、カルボキシル基等であってよい。）との間で形成させることができる。 In the protein composition according to this embodiment, the modified hydroxyl group-containing polymer and the protein are preferably hydrogen bonded. Thereby, the functionality of a protein composition improves more. The hydrogen bond is, for example, a functional group in a modified hydroxyl group-containing polymer (eg, a hydroxyl group, a functional functional group, a functional group in a binding functional group, etc.) and a functional group in a protein (for example, And an amino group, a carboxyl group, etc.).
　タンパク質組成物における、タンパク質の含有量は、タンパク質組成物全量を基準として、３０～９９．９９９質量％であってよく、３５～９９．９９質量％であるのが好ましく、４０～９９．９質量％であるのがより好ましい。 The protein content in the protein composition may be 30 to 99.999% by mass, preferably 35 to 99.99% by mass, and 40 to 99.9% by mass based on the total amount of the protein composition. % Is more preferred.
　タンパク質組成物における、修飾ヒドロキシル基含有ポリマーの含有量は、タンパク質組成物全量を基準として、０．００１～７０質量％であってよく、０．０１～６５質量％であるのが好ましく、０．１～６０質量％であるのがより好ましい。 The content of the modified hydroxyl group-containing polymer in the protein composition may be 0.001 to 70% by mass, preferably 0.01 to 65% by mass, based on the total amount of the protein composition. It is more preferably 1 to 60% by mass.
　本実施形態に係るタンパク質組成物は、更にヒドロキシル基含有ポリマーを含むものであってもよい。当該ヒドロキシル基含有ポリマーは、修飾ヒドロキシル基含有ポリマーの原料であるヒドロキシル基含有ポリマーと同種のポリマーであることが好ましい。 The protein composition according to the present embodiment may further contain a hydroxyl group-containing polymer. The hydroxyl group-containing polymer is preferably the same type of polymer as the hydroxyl group-containing polymer that is a raw material for the modified hydroxyl group-containing polymer.
　本実施形態に係るタンパク質組成物がヒドロキシル基含有ポリマーを含む場合、ヒドロキシル基含有ポリマーの含有量は、修飾ヒドロキシル基含有ポリマーとヒドロキシル基含有ポリマーの総量１００質量％に対して、５０質量％以上であってよく、６０質量％以上であってよく、７０質量％以上であってもよく、８０質量％以上であってもよい。また上限としては、９０質量％以下であってよい。 When the protein composition according to the present embodiment includes a hydroxyl group-containing polymer, the content of the hydroxyl group-containing polymer is 50% by mass or more with respect to 100% by mass of the total amount of the modified hydroxyl group-containing polymer and the hydroxyl group-containing polymer. It may be 60 mass% or more, 70 mass% or more, or 80 mass% or more. Moreover, as an upper limit, it may be 90 mass% or less.
　本実施形態に係るタンパク質組成物は、その形態、用途等に応じて、更に他の添加剤を含むものであってもよい。添加剤としては、例えば、可塑剤、レベリング剤、架橋剤、結晶核剤、酸化防止剤、紫外線吸収剤、着色剤、フィラー、及び合成樹脂が挙げられる。添加剤の含有量は、タンパク質の全量１００質量部に対して、５０質量部以下であってよい。 The protein composition according to the present embodiment may further contain other additives depending on the form, use, and the like. Examples of the additive include a plasticizer, a leveling agent, a crosslinking agent, a crystal nucleating agent, an antioxidant, an ultraviolet absorber, a colorant, a filler, and a synthetic resin. The content of the additive may be 50 parts by mass or less with respect to 100 parts by mass of the total amount of protein.
　本実施形態に係るタンパク質組成物は、粉末状、ペースト状、液状（例えば、懸濁液、溶液）のいずれの形態であってもよい。また、本実施形態に係るタンパク質組成物は、原料組成物の形態の他、当該タンパク質組成物を含む、又は当該タンパク質組成物からなる成形体（例えば、繊維、フィルム、多孔質体、パーティクル、モールド成形体）の形態であってもよい。 The protein composition according to the present embodiment may be in any form of powder, paste, or liquid (for example, suspension or solution). In addition to the form of the raw material composition, the protein composition according to the present embodiment includes a protein composition, or a molded body comprising the protein composition (for example, fibers, films, porous bodies, particles, molds). It may be in the form of a molded body).
　本実施形態に係るタンパク質組成物は、当該タンパク質組成物を含む、又は当該タンパク質組成物からなる製品であってもよい。製品としては、例えば、繊維、糸、フィラメント、フィルム、発泡体、球体、ナノフィブリル、ヒドロゲル、樹脂及びその等価物からなる群から選択される製品が挙げられる。これらは、特開２００９－５０５６６８号公報、特許第５６７８２８３号公報、特許第４６３８７３５号公報等に記載の方法に準じて製造することができる。 The protein composition according to the present embodiment may be a product containing or consisting of the protein composition. Examples of the product include a product selected from the group consisting of fibers, yarns, filaments, films, foams, spheres, nanofibrils, hydrogels, resins, and equivalents. These can be produced according to the methods described in JP-A-2009-505668, JP-A-5678283, JP-A-4638735 and the like.
　本発明に係るタンパク質組成物を含む、又は当該タンパク質組成物からなるタンパク質繊維は、繊維又は糸として、織物、編物、組み物、不織布等に応用できる。また、ロープ、手術用縫合糸、電気部品用の可撓性止め具、さらには移植用生理活性材料（例えば、人工靭帯及び大動脈バンド）等の高強度用途にも応用できる。 The protein fiber containing or consisting of the protein composition according to the present invention can be applied to woven fabrics, knitted fabrics, braided fabrics, non-woven fabrics and the like as fibers or yarns. It can also be applied to high-strength applications such as ropes, surgical sutures, flexible stops for electrical components, and bioactive materials for transplantation (eg, artificial ligaments and aortic bands).
（ドープ液）
　本実施形態に係るタンパク質組成物は、ドープ液であってもよい。本実施形態に係るドープ液は、修飾ヒドロキシル基含有ポリマーと、タンパク質と、溶媒とを少なくとも含む。本実施形態に係るドープ液は、更に溶解促進剤を含むものであってもよい。 (Dope solution)
The protein composition according to the present embodiment may be a dope solution. The dope liquid according to this embodiment includes at least a modified hydroxyl group-containing polymer, a protein, and a solvent. The dope liquid according to the present embodiment may further contain a dissolution accelerator.
　溶媒としては、例えば、ヘキサフルオロイソプロパノール（ＨＦＩＰ）、ヘキサフルオロアセトン（ＨＦＡ）、ジメチルスルホキシド（ＤＭＳＯ）、Ｎ，Ｎ－ジメチルホルムアミド（ＤＭＦ）、ギ酸、並びに尿素、グアニジン、ドデシル硫酸ナトリウム（ＳＤＳ）、臭化リチウム、塩化カルシウム及びチオシアン酸リチウム等を含む水溶液等を挙げることができる。これらの溶媒は、１種単独で使用してもよく、２種以上を混合して使用してもよい。 Examples of the solvent include hexafluoroisopropanol (HFIP), hexafluoroacetone (HFA), dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), formic acid, and urea, guanidine, sodium dodecyl sulfate (SDS), Examples include an aqueous solution containing lithium bromide, calcium chloride, lithium thiocyanate, and the like. These solvents may be used alone or in combination of two or more.
　ドープ液におけるタンパク質の含有量は、ドープ液の全質量を基準として、１５質量％以上、３０質量％以上、４０質量％以上又は５０質量％以上であってよい。タンパク質の含有量は、ドープ液の製造効率の観点から、ドープ液の全質量を基準として、７０質量％以下、６５質量％以下、又は６０質量％以下であってよい。 The protein content in the dope solution may be 15% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more based on the total mass of the dope solution. The content of the protein may be 70% by mass or less, 65% by mass or less, or 60% by mass or less based on the total mass of the dope solution from the viewpoint of the production efficiency of the dope solution.
　溶解促進剤としては、例えば、以下に示すルイス酸とルイス塩基とからなる無機塩が挙げられる。ルイス塩基としては、例えば、オキソ酸イオン（硝酸イオン、過塩素酸イオン等）、金属オキソ酸イオン（過マンガン酸イオン等）、ハロゲン化物イオン、チオシアン酸イオン、シアン酸イオン等が挙げられる。ルイス酸としては、例えば、アルカリ金属イオン、アルカリ土類金属イオン等の金属イオン、アンモニウムイオン等の多原子イオン、錯イオン等が挙げられる。ルイス酸とルイス塩基とからなる無機塩の具体例としては、塩化リチウム、臭化リチウム、ヨウ化リチウム、硝酸リチウム、過塩素酸リチウム、及びチオシアン酸リチウム等のリチウム塩、塩化カルシウム、臭化カルシウム、ヨウ化カルシウム、硝酸カルシウム、過塩素酸カルシウム、及びチオシアン酸カルシウム等のカルシウム塩、塩化鉄、臭化鉄、ヨウ化鉄、硝酸鉄、過塩素酸鉄、及びチオシアン酸鉄等の鉄塩、塩化アルミニウム、臭化アルミニウム、ヨウ化アルミニウム、硝酸アルミニウム、過塩素酸アルミニウム、及びチオシアン酸アルミニウム等のアルミニウム塩、塩化カリウム、臭化カリウム、ヨウ化カリウム、硝酸カリウム、過塩素酸カリウム、及びチオシアン酸カリウム等のカリウム塩、塩化ナトリウム、臭化ナトリウム、ヨウ化ナトリウム、硝酸ナトリウム、過塩素酸ナトリウム、及びチオシアン酸ナトリウム等のナトリウム塩、塩化亜鉛、臭化亜鉛、ヨウ化亜鉛、硝酸亜鉛、過塩素酸亜鉛、及びチオシアン酸亜鉛等の亜鉛塩、塩化マグネシウム、臭化マグネシウム、ヨウ化マグネシウム、硝酸マグネシウム、過塩素酸マグネシウム、及びチオシアン酸マグネシウム等のマグネシウム塩、塩化バリウム、臭化バリウム、ヨウ化バリウム、硝酸バリウム、過塩素酸バリウム、及びチオシアン酸バリウム等のバリウム塩、並びに塩化ストロンチウム、臭化ストロンチウム、ヨウ化ストロンチウム、硝酸ストロンチウム、過塩素酸ストロンチウム、及びチオシアン酸ストロンチウム等のストロンチウム塩が挙げられる。 Examples of the dissolution accelerator include inorganic salts composed of the following Lewis acid and Lewis base. Examples of the Lewis base include oxo acid ions (nitrate ions, perchlorate ions, etc.), metal oxo acid ions (permanganate ions, etc.), halide ions, thiocyanate ions, cyanate ions, and the like. Examples of the Lewis acid include metal ions such as alkali metal ions and alkaline earth metal ions, polyatomic ions such as ammonium ions, complex ions, and the like. Specific examples of inorganic salts composed of a Lewis acid and a Lewis base include lithium salts such as lithium chloride, lithium bromide, lithium iodide, lithium nitrate, lithium perchlorate, and lithium thiocyanate, calcium chloride, calcium bromide. Calcium salts such as calcium iodide, calcium nitrate, calcium perchlorate and calcium thiocyanate, iron salts such as iron chloride, iron bromide, iron iodide, iron nitrate, iron perchlorate and iron thiocyanate, Aluminum salts such as aluminum chloride, aluminum bromide, aluminum iodide, aluminum nitrate, aluminum perchlorate, and aluminum thiocyanate, potassium chloride, potassium bromide, potassium iodide, potassium nitrate, potassium perchlorate, and potassium thiocyanate Potassium salt, sodium chloride, sodium bromide, etc. Sodium salts such as sodium uride, sodium nitrate, sodium perchlorate and sodium thiocyanate, zinc salts such as zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc perchlorate and zinc thiocyanate, chloride Magnesium salts such as magnesium, magnesium bromide, magnesium iodide, magnesium nitrate, magnesium perchlorate, and magnesium thiocyanate, barium chloride, barium bromide, barium iodide, barium nitrate, barium perchlorate, and barium thiocyanate And strontium salts such as strontium chloride, strontium bromide, strontium iodide, strontium nitrate, strontium perchlorate, and strontium thiocyanate.
　溶解促進剤の含有量は、タンパク質の全量１００質量部に対して、１．０質量部以上、５．０質量部以上、９．０質量部以上、１５質量部以上又は２０．０質量部以上であってよい。溶解促進剤の含有量は、タンパク質の全量１００質量部に対して、４０質量部以下、３５質量部以下又は３０質量部以下であってよい。 Content of a solubility promoter is 1.0 mass part or more, 5.0 mass part or more, 9.0 mass part or more, 15 mass part or more, or 20.0 mass part or more with respect to 100 mass parts of protein whole quantity. It may be. The content of the dissolution promoter may be 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less with respect to 100 parts by mass of the total amount of protein.
　本実施形態に係るドープ液の製造方法は、例えば、溶媒にタンパク質及び修飾ヒドロキシル基含有ポリマーを溶解させる工程を含むものであってもよく（第１の製造方法）、また、溶媒にタンパク質、ヒドロキシル基含有ポリマー及び機能性官能基を有する反応剤を溶解させる工程と、（タンパク質共存下で）ヒドロキシル基含有ポリマーと機能性官能基を有する反応剤とを反応させて修飾ヒドロキシル基含有ポリマーを得る工程とを含むものであってもよい（第２の製造方法）。 The method for producing a dope solution according to the present embodiment may include, for example, a step of dissolving a protein and a modified hydroxyl group-containing polymer in a solvent (first production method). A step of dissolving a group-containing polymer and a reactive agent having a functional functional group, and a step of obtaining a modified hydroxyl group-containing polymer by reacting the hydroxyl group-containing polymer with a functional functional group (in the presence of protein). (2nd manufacturing method).
　ヒドロキシル基含有ポリマーと機能性官能基を有する反応剤との反応が効率よく進むという観点から、本実施形態に係るドープ液は、第１の製造方法で得ることが好ましい。第１の製造方法において、溶媒にタンパク質及び修飾ヒドロキシル基含有ポリマーを溶解させる工程は、修飾ヒドロキシル基含有ポリマーとタンパク質を溶媒に溶解させる順序に制限はなく、修飾ヒドロキシル基含有ポリマーを溶媒に溶解させてから、その溶液にタンパク質を溶解させてもよく、タンパク質を溶媒に溶解させてから、その溶液に修飾ヒドロキシル基含有ポリマーを溶解させてもよく、タンパク質及び修飾ヒドロキシル基含有ポリマーを一緒に溶媒に溶解させてもよい。また、溶媒中でヒドロキシル基含有ポリマーと機能性官能基を有する反応剤とを反応させて修飾ヒドロキシル基含有ポリマーを得た後、その溶液（反応液）にタンパク質を添加して溶解させてもよい。 From the viewpoint that the reaction between the hydroxyl group-containing polymer and the functional agent-containing reactive agent proceeds efficiently, the dope liquid according to this embodiment is preferably obtained by the first production method. In the first production method, the step of dissolving the protein and the modified hydroxyl group-containing polymer in the solvent is not limited in the order of dissolving the modified hydroxyl group-containing polymer and the protein in the solvent, and the modified hydroxyl group-containing polymer is dissolved in the solvent. Then, the protein may be dissolved in the solution, the protein may be dissolved in the solvent, and then the modified hydroxyl group-containing polymer may be dissolved in the solution. The protein and the modified hydroxyl group-containing polymer may be dissolved together in the solvent. It may be dissolved. Moreover, after reacting a hydroxyl group-containing polymer and a reactive agent having a functional functional group in a solvent to obtain a modified hydroxyl group-containing polymer, protein may be added to the solution (reaction solution) and dissolved. .
　本実施形態に係るドープ液の製造時に、３０～９０℃に加温してもよい。使用する溶媒、タンパク質及び修飾ヒドロキシル基含有ポリマーの種類等に応じて溶解可能な温度を適時設定すればよい。溶解を促進するために振盪、撹拌してもよい。 In the production of the dope solution according to the present embodiment, it may be heated to 30 to 90 ° C. What is necessary is just to set the temperature which can be melt | dissolved timely according to the kind of solvent, protein, modified hydroxyl group containing polymer, etc. to be used. It may be shaken and stirred to promote dissolution.
　本実施形態に係るドープ液の粘度は、ドープ液の用途等に応じて適宜設定してよい。例えば、本実施形態に係るドープ液を紡糸原液として使用する場合、その粘度は、紡糸方法に応じて適宜設定してよく、例えば、３５℃において１００～１５，０００ｃＰ（センチポイズ）、４０℃において１００～３０，０００ｃＰ（センチポイズ）等に設定すればよい。紡糸原液の粘度は、例えば京都電子工業社製の商品名“ＥＭＳ粘度計”を使用して測定することができる。 The viscosity of the dope solution according to the present embodiment may be appropriately set according to the use of the dope solution. For example, when the dope solution according to the present embodiment is used as a spinning stock solution, the viscosity thereof may be appropriately set according to the spinning method, for example, 100 to 15,000 cP (centipoise) at 35 ° C., 100 at 40 ° C. It may be set to ˜30,000 cP (centipoise) or the like. The viscosity of the spinning dope can be measured using, for example, a trade name “EMS viscometer” manufactured by Kyoto Electronics Industry Co., Ltd.
〔タンパク質組成物の製造方法〕
　本実施形態に係るタンパク質組成物の製造方法は、ａ）機能性官能基を有する反応剤とヒドロキシル基含有ポリマーとを反応させて、ヒドロキシル基含有ポリマーに機能性官能基が結合した修飾ヒドロキシル基含有ポリマーを得る工程と、ｂ）修飾ヒドロキシル基含有ポリマーとタンパク質とを結合させる工程とを備える。 [Producing method of protein composition]
In the method for producing a protein composition according to this embodiment, a) a reactive functional group-containing reactive hydroxyl group-containing polymer is reacted with a hydroxyl group-containing polymer so that the functional group is bonded to the hydroxyl group-containing polymer. Obtaining a polymer; and b) coupling the modified hydroxyl group-containing polymer and the protein.
　ａ）工程は、タンパク質の存在下で実施してもよく、タンパク質の非存在下で実施してもよい。ａ）工程をタンパク質の非存在下で実施した場合は、反応により得た修飾ヒドロキシル基含有ポリマーとタンパク質とを混合した後、ｂ）工程を実施すればよい。ａ）工程をタンパク質の存在下で実施した場合は、反応終了後又は反応中にｂ）工程を実施することができる。 A) The step may be performed in the presence of protein or may be performed in the absence of protein. When the step a) is carried out in the absence of protein, the modified hydroxyl group-containing polymer obtained by the reaction and the protein are mixed, and then the step b) may be carried out. When the step a) is carried out in the presence of protein, the step b) can be carried out after or during the reaction.
　ａ）工程は、溶媒中で実施してもよい。この場合、上述したドープ液の製造方法と同様にしてａ）工程を実施することができる。 A) The step may be performed in a solvent. In this case, the step a) can be performed in the same manner as in the above-described method for producing a dope solution.
　ａ）工程における反応条件は、使用する機能性官能基を有する反応剤、ヒドロキシル基含有ポリマーの種類に応じて、反応が進行する条件を適宜設定してよい。例えば、機能性官能基を有する反応剤が、機能性官能基を有するイソシアネートであり、ヒドロキシル基含有ポリマーが、多糖類である場合、反応温度は、８０～１００℃の間で設定することができ、反応時間は２～４時間の間で設定することができる。 A) The reaction conditions in the step may be appropriately set according to the type of the reactive agent having a functional functional group and the hydroxyl group-containing polymer to be used. For example, when the reactive agent having a functional functional group is an isocyanate having a functional functional group and the hydroxyl group-containing polymer is a polysaccharide, the reaction temperature can be set between 80 to 100 ° C. The reaction time can be set between 2 and 4 hours.
　また、反応液中の機能性官能基を有する反応剤、及びヒドロキシル基含有ポリマーのモル濃度比は、修飾ヒドロキシル基含有ポリマーの修飾率（反応可能な全官能基数に対して、機能性官能基が結合した官能基数の割合）が所望の値となるように設定すればよい。例えば、修飾率を１００％としたい場合、機能性官能基を有する反応剤、及びヒドロキシル基含有ポリマーの反応可能な官能基が等モルになるようにモル濃度比を設定することができる。 In addition, the molar concentration ratio of the reactive agent having a functional functional group and the hydroxyl group-containing polymer in the reaction solution is determined based on the modification rate of the modified hydroxyl group-containing polymer (the functional functional group has a ratio to the total number of functional groups capable of reaction). The ratio of the number of bonded functional groups) may be set to a desired value. For example, when the modification rate is desired to be 100%, the molar concentration ratio can be set so that the reactive functional group and the reactive functional group of the hydroxyl group-containing polymer are equimolar.
　ｂ）工程は、修飾ヒドロキシル基含有ポリマーとタンパク質とを結合させる工程である。修飾ヒドロキシル基含有ポリマーとタンパク質との結合は、例えば、両ポリマーが絡み合うことによる結合であってもよく、イオン結合による結合であってもよく、水素結合による結合であってもよい。 B) The step is a step of binding the modified hydroxyl group-containing polymer and the protein. The bond between the modified hydroxyl group-containing polymer and the protein may be, for example, a bond caused by entanglement of both polymers, a bond due to an ionic bond, or a bond due to hydrogen bond.
　修飾ヒドロキシル基含有ポリマーとタンパク質との結合は、例えば、溶媒に修飾ヒドロキシル基含有ポリマー及びタンパク質を溶解させ、両者を会合させることで進行させることができる。溶解させることで自発的に結合させるものであってもよく、溶解後、濃縮することで結合させるものであってもよく、溶解後、脱溶媒剤に接触させて溶媒を離脱させることで結合させるものであってもよい。 The binding between the modified hydroxyl group-containing polymer and the protein can proceed, for example, by dissolving the modified hydroxyl group-containing polymer and protein in a solvent and associating both. It may be bonded spontaneously by dissolving, or may be bonded by concentrating after dissolution, or bonded by releasing the solvent by contacting with a desolvent after dissolution. It may be a thing.
　すなわち、ｂ）工程は、ｂ－１）修飾ヒドロキシル基含有ポリマーとタンパク質と溶媒とを含むドープ液を得るステップと、ｂ－２）ドープ液を脱溶媒剤に接触させて、該ドープ液から溶媒を離脱させることにより、タンパク質と修飾ヒドロキシル基含有ポリマーとを水素結合させるステップと、を含むものであってもよい。 That is, b) step includes b-1) obtaining a dope solution containing a modified hydroxyl group-containing polymer, a protein and a solvent; and b-2) bringing the dope solution into contact with a desolvent and removing the solvent from the dope solution. And a step of hydrogen bonding the protein and the modified hydroxyl group-containing polymer by releasing them.
　ドープ液の好ましい態様は、上述のとおりである。脱溶媒剤としては、脱溶媒できる溶液であればよく、例えば、メタノール、エタノール及び２－プロパノール等の炭素数１～５の低級アルコール、並びにアセトン等を挙げることができる。脱溶媒剤は、適宜水を含んでいてもよい。 The preferred embodiment of the dope solution is as described above. The desolvent may be any solution that can be desolvated, and examples thereof include lower alcohols having 1 to 5 carbon atoms such as methanol, ethanol, and 2-propanol, and acetone. The solvent removal agent may contain water as appropriate.
　また、ｂ－２）ステップは、ドープ液から溶媒を離脱させることにより、タンパク質と修飾ヒドロキシル基含有ポリマーとを水素結合させると共に、タンパク質を凝固させて成形し、タンパク質と修飾ヒドロキシル基含有ポリマーとを含有する成形体を得ることを更に含むものであってもよい。 In the step b-2), the solvent is removed from the dope solution to hydrogen bond the protein and the modified hydroxyl group-containing polymer, and the protein is solidified to form the protein and the modified hydroxyl group-containing polymer. It may further include obtaining a shaped body to be contained.
（成形体）
　本実施形態に係るタンパク質組成物が成形体である場合、成形体の形状は特に限定されず、例えば、繊維、フィルム、多孔質体、パーティクル、モールド成形体等であってよい。成形体は、例えば、原料組成物として調製したタンパク質組成物（例えば、上述したドープ液等の液状のタンパク質組成物）を成形することで製造することができる。 (Molded body)
When the protein composition according to the present embodiment is a molded body, the shape of the molded body is not particularly limited, and may be, for example, a fiber, a film, a porous body, particles, a molded body, or the like. A molded object can be manufactured by shape | molding the protein composition (For example, liquid protein compositions, such as the dope liquid mentioned above) prepared as a raw material composition, for example.
　フィルム状の成形体（タンパク質フィルム）は、例えば、上述したドープ液の膜を形成し、形成された膜から溶媒を除去する方法により得られる。 The film-like molded body (protein film) is obtained, for example, by a method of forming the above-described dope solution film and removing the solvent from the formed film.
　繊維状の成形体（タンパク質繊維）は、例えば、上述したドープ液を紡糸し、紡糸されたドープ液から溶媒を除去する方法により得られる。 The fibrous shaped body (protein fiber) is obtained, for example, by a method of spinning the dope solution described above and removing the solvent from the spun dope solution.
　多孔質状の成形体（タンパク質多孔質体）は、フィブロイン由来タンパク質より多孔質体を製造する方法が国際公開第２０１４／１７５１７８号に記載されており、基本的にこの方法によって得られる。 A method for producing a porous body from a fibroin-derived protein is described in International Publication No. 2014/175178, and the porous shaped body (protein porous body) is basically obtained by this method.
　パーティクル状の成形体（タンパク質パーティクル）は、例えば、上述したドープ液を用い、ドープ液中の溶媒を水溶性溶媒に置換することによりタンパク質の水溶液を得る工程と、タンパク質の水溶液を乾燥する工程とを含む方法によって得られる。水溶性溶媒は、水を含む溶媒をいい、例えば、水、水溶性緩衝液、生理食塩水等が挙げられる。水溶性溶媒に置換する工程は、ドープ液を透析膜内に入れ、水溶性溶媒中に浸漬し、水溶性溶媒を１回以上入れ替える方法により行われることが好ましい。具体的には、ドープ液を透析膜に入れ、ドープ液の１００倍以上の量の水溶性溶媒（１回分）の中に３時間静置し、この水溶性溶媒入れ替えを計３回以上繰り返すことがより好ましい。透析膜は、タンパク質が透過させないものであればよく、例えばセルロース透析膜等であってよい。水溶性溶媒の置換を繰り返すことにより、ドープ液中に存在していた溶媒の量をゼロに近づけることができる。水溶性溶媒に置換する工程の後半では、透析膜は使用しなくてもよい。タンパク質の水溶液を乾燥する工程は、真空凍結乾燥を用いることが好ましい。真空凍結乾燥時の真空度は、好ましくは２００パスカル（Ｐａ）以下、より好ましくは１５０パスカル以下、更に好ましくは１００パスカル以下である。凍結乾燥後のパーティクルにおける水分率は、好ましくは５．０％以下、より好ましくは３．０％以下である。 The particle-shaped molded body (protein particle) includes, for example, a step of obtaining an aqueous protein solution by replacing the solvent in the dope solution with a water-soluble solvent, and a step of drying the aqueous protein solution. Obtained by a method comprising: The water-soluble solvent refers to a solvent containing water, and examples thereof include water, a water-soluble buffer solution, and physiological saline. The step of substituting with a water-soluble solvent is preferably performed by a method in which the dope solution is placed in a dialysis membrane, immersed in the water-soluble solvent, and the water-soluble solvent is replaced one or more times. Specifically, the dope solution is put into a dialysis membrane and left in a water-soluble solvent (one dose) more than 100 times the dope solution for 3 hours, and this water-soluble solvent exchange is repeated a total of 3 times or more. Is more preferable. The dialysis membrane may be any material that does not allow protein permeation, and may be, for example, a cellulose dialysis membrane. By repeating the replacement of the water-soluble solvent, the amount of the solvent present in the dope liquid can be brought close to zero. In the latter half of the step of substituting with a water-soluble solvent, the dialysis membrane may not be used. The step of drying the aqueous protein solution is preferably performed by vacuum freeze drying. The degree of vacuum during vacuum freeze-drying is preferably 200 Pascals (Pa) or less, more preferably 150 Pascals or less, and even more preferably 100 Pascals or less. The moisture content in the particles after freeze-drying is preferably 5.0% or less, more preferably 3.0% or less.
　モールド成形体は、例えば、国際公開第２０１７／０４７５０４号の明細書にフィブロイン由来タンパク質よりモールド成形体を製造する方法が記載されており、基本的にこの方法によって得られる。なお、フィブロイン由来タンパク質よりモールド成形体を製造する際には、例えば以下の操作が実施される。即ち、先ず、タンパク質を含む組成物（タンパク質のみ、或いは他の成分を含む）を加圧成形機の金型に導入した後、金型を加熱すると共に組成物に対して加圧する。所定の加圧下でタンパク質が所定の温度に達するまで加熱及び加圧を継続して、加熱加圧された組成物を得る。次いで、冷却器（例えばスポットクーラー）を用いて金型の温度を下降させ、組成物が所定の温度になったところで、内容物を取り出してモールド成形体を得る。加熱は、８０～３００℃で行うことが好ましく、１００～１８０℃がより好ましく、１００～１３０℃が更に好ましい。加圧は、５ｋＮ以上で行うことが好ましく、１０ｋＮ以上がより好ましく、２０ｋＮ以上が更に好ましい。また、所定の加熱加圧条件に達した後、その条件での処理を続ける時間（保温条件）は、０～１００分が好ましく、１～５０分がより好ましく、５～３０分が更に好ましい。 For example, a method for producing a molded product from a fibroin-derived protein is described in the specification of International Publication No. 2017/047504, and is basically obtained by this method. In addition, when manufacturing a molding from a fibroin origin protein, the following operation is implemented, for example. That is, first, a composition containing protein (including only protein or other components) is introduced into a mold of a pressure molding machine, and then the mold is heated and pressurized against the composition. Heating and pressurization are continued until the protein reaches a predetermined temperature under a predetermined pressure to obtain a heat-pressed composition. Next, the temperature of the mold is lowered using a cooler (for example, a spot cooler), and when the composition reaches a predetermined temperature, the contents are taken out to obtain a molded body. Heating is preferably performed at 80 to 300 ° C, more preferably 100 to 180 ° C, and still more preferably 100 to 130 ° C. The pressurization is preferably performed at 5 kN or more, more preferably 10 kN or more, and further preferably 20 kN or more. In addition, after reaching a predetermined heating and pressing condition, the time for which the treatment is continued under the condition (heat retaining condition) is preferably 0 to 100 minutes, more preferably 1 to 50 minutes, and further preferably 5 to 30 minutes.
　以下、実施例に基づいて本発明をより具体的に説明する。ただし、本発明は以下の実施例に限定されるものではない。 Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.
〔改変フィブロインの製造〕
（１）発現ベクターの作製
　ネフィラ・クラビペス（Ｎｅｐｈｉｌａ　ｃｌａｖｉｐｅｓ）由来のフィブロイン（ＧｅｎＢａｎｋアクセッション番号：Ｐ４６８０４．１、ＧＩ：１１７４４１５）の塩基配列及びアミノ酸配列に基づき、配列番号１５で示されるアミノ酸配列を有する改変フィブロイン（「ＰＲＴ７９９」ともいう。）を設計した。なお、配列番号１５で示されるアミノ酸配列は、ネフィラ・クラビペス由来のフィブロインのアミノ酸配列に対して、生産性の向上を目的としてアミノ酸残基の置換、挿入及び欠失を施したアミノ酸配列を有し、さらにＮ末端に配列番号１２で示されるアミノ酸配列（タグ配列及びヒンジ配列）が付加されている。 [Production of modified fibroin]
(1) Preparation of expression vector Based on the nucleotide sequence and amino acid sequence of fibroin (GenBank accession numbers: P46804.1, GI: 1174415) derived from Nephila clavipes, it has the amino acid sequence represented by SEQ ID NO: 15. A modified fibroin (also referred to as “PRT799”) was designed. The amino acid sequence represented by SEQ ID NO: 15 has an amino acid sequence in which substitution, insertion and deletion of amino acid residues are performed for the purpose of improving productivity with respect to the amino acid sequence of fibroin derived from Nephila clavipes. Furthermore, the amino acid sequence (tag sequence and hinge sequence) represented by SEQ ID NO: 12 is added to the N-terminus.
　次に、ＰＲＴ７９９をコードする核酸を合成した。当該核酸には、５’末端にＮｄｅＩサイト及び終止コドン下流にＥｃｏＲＩサイトを付加した。当該核酸をクローニングベクター（ｐＵＣ１１８）にクローニングした。その後、同核酸をＮｄｅＩ及びＥｃｏＲＩで制限酵素処理して切り出した後、タンパク質発現ベクターｐＥＴ－２２ｂ（＋）に組換えて発現ベクターを得た。 Next, a nucleic acid encoding PRT799 was synthesized. The nucleic acid was added with an NdeI site at the 5 'end and an EcoRI site downstream of the stop codon. The nucleic acid was cloned into a cloning vector (pUC118). Thereafter, the nucleic acid was cleaved by restriction enzyme treatment with NdeI and EcoRI, and then recombined with the protein expression vector pET-22b (+) to obtain an expression vector.
（２）タンパク質の発現
　ＰＲＴ７９９をコードする核酸を含むｐＥＴ－２２ｂ（＋）発現ベクターで、大腸菌ＢＬＲ（ＤＥ３）を形質転換した。当該形質転換大腸菌を、アンピシリンを含む２ｍＬのＬＢ培地で１５時間培養した。当該培養液を、アンピシリンを含む１００ｍＬのシード培養用培地（表４）にＯＤ６００が０．００５となるように添加した。培養液温度を３０℃に保ち、ＯＤ６００が５になるまでフラスコ培養を行い（約１５時間）、シード培養液を得た。 (2) Expression of protein E. coli BLR (DE3) was transformed with a pET-22b (+) expression vector containing a nucleic acid encoding PRT799. The transformed Escherichia coli was cultured in 2 mL of LB medium containing ampicillin for 15 hours. The culture solution was added to 100 mL of a seed culture medium (Table 4) containing ampicillin so that the OD 600 was 0.005. The culture temperature was kept at 30 ° C., and flask culture was performed until the OD 600 reached 5 (about 15 hours) to obtain a seed culture solution.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　当該シード培養液を５００ｍＬの生産培地（表５）を添加したジャーファーメンターにＯＤ６００が０．０５となるように添加した。培養液温度を３７℃に保ち、ｐＨ６．９で一定に制御して培養した。また培養液中の溶存酸素濃度を、溶存酸素飽和濃度の２０％に維持するようにした。 The seed culture was added to a jar fermenter to which 500 mL of production medium (Table 5) was added so that the OD 600 was 0.05. The culture solution temperature was maintained at 37 ° C., and the culture was performed at a constant pH of 6.9. Further, the dissolved oxygen concentration in the culture solution was maintained at 20% of the dissolved oxygen saturation concentration.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　生産培地中のグルコースが完全に消費された直後に、フィード液（グルコース４５５ｇ／１Ｌ、Ｙｅａｓｔ　Ｅｘｔｒａｃｔ　１２０ｇ／１Ｌ）を１ｍＬ／分の速度で添加した。培養液温度を３７℃に保ち、ｐＨ６．９で一定に制御して培養した。また培養液中の溶存酸素濃度を、溶存酸素飽和濃度の２０％に維持するようにし、２０時間培養を行った。その後、１Ｍのイソプロピル－β－チオガラクトピラノシド（ＩＰＴＧ）を培養液に対して終濃度１ｍＭになるよう添加し、改変フィブロインを発現誘導させた。ＩＰＴＧ添加後２０時間経過した時点で、培養液を遠心分離し、菌体を回収した。ＩＰＴＧ添加前とＩＰＴＧ添加後の培養液から調製した菌体を用いてＳＤＳ－ＰＡＧＥを行い、ＩＰＴＧ添加に依存した目的とする改変フィブロインサイズのバンドの出現により、目的とする改変フィブロインの発現を確認した。 Immediately after the glucose in the production medium was completely consumed, a feed solution (glucose 455 g / 1 L, Yeast Extract 120 g / 1 L) was added at a rate of 1 mL / min. The culture solution temperature was maintained at 37 ° C., and the culture was performed at a constant pH of 6.9. In addition, the dissolved oxygen concentration in the culture solution was maintained at 20% of the dissolved oxygen saturation concentration, and cultured for 20 hours. Thereafter, 1M isopropyl-β-thiogalactopyranoside (IPTG) was added to the culture solution to a final concentration of 1 mM to induce expression of the modified fibroin. At the time when 20 hours passed after the addition of IPTG, the culture solution was centrifuged, and the cells were collected. Perform SDS-PAGE using cells prepared from the culture before and after adding IPTG, and confirm the expression of the desired modified fibroin by the appearance of the desired modified fibroin size band depending on the addition of IPTG. did.
（３）タンパク質の精製
　ＩＰＴＧを添加してから２時間後に回収した菌体を２０ｍＭ　Ｔｒｉｓ－ＨＣｌ　ｂｕｆｆｅｒ（ｐＨ７．４）で洗浄した。洗浄後の菌体を約１ｍＭのＰＭＳＦを含む２０ｍＭ　Ｔｒｉｓ－ＨＣｌ緩衝液（ｐＨ７．４）に懸濁させ、高圧ホモジナイザー（ＧＥＡ　Ｎｉｒｏ　Ｓｏａｖｉ社製）で細胞を破砕した。破砕した細胞を遠心分離し、沈殿物を得た。得られた沈殿物を、高純度になるまで２０ｍＭ　Ｔｒｉｓ－ＨＣｌ緩衝液（ｐＨ７．４）で洗浄した。洗浄後の沈殿物を１００ｍｇ／ｍＬの濃度になるように８Ｍ　グアニジン緩衝液（８Ｍ　グアニジン塩酸塩、１０ｍＭ　リン酸二水素ナトリウム、２０ｍＭ　ＮａＣｌ、１ｍＭ　Ｔｒｉｓ－ＨＣｌ、ｐＨ７．０）で懸濁し、６０℃で３０分間、スターラーで撹拌し、溶解させた。溶解後、透析チューブ（三光純薬株式会社製のセルロースチューブ３６／３２）を用いて水で透析を行った。透析後に得られた白色の凝集タンパク質を遠心分離により回収し、凍結乾燥機で水分を除き、凍結乾燥粉末を回収することにより、改変フィブロイン（ＰＲＴ７９９）を得た。 (3) Protein purification The cells recovered 2 hours after the addition of IPTG were washed with 20 mM Tris-HCl buffer (pH 7.4). The washed cells were suspended in 20 mM Tris-HCl buffer (pH 7.4) containing about 1 mM PMSF, and the cells were disrupted with a high-pressure homogenizer (GEA Niro Soavi). The disrupted cells were centrifuged to obtain a precipitate. The resulting precipitate was washed with 20 mM Tris-HCl buffer (pH 7.4) until high purity. The washed precipitate was suspended in 8M guanidine buffer (8M guanidine hydrochloride, 10 mM sodium dihydrogen phosphate, 20 mM NaCl, 1 mM Tris-HCl, pH 7.0) to a concentration of 100 mg / mL, and 60 ° C. And stirred for 30 minutes with a stirrer to dissolve. After dissolution, dialysis was performed with water using a dialysis tube (cellulose tube 36/32 manufactured by Sanko Junyaku Co., Ltd.). The white aggregated protein obtained after dialysis was collected by centrifugation, water was removed with a freeze dryer, and the freeze-dried powder was collected to obtain modified fibroin (PRT799).
〔タンパク質繊維の製造及び評価〕
（実施例１）
＜紡糸原液（ドープ液）の調製＞
　デンプン（和光純薬工業株式会社製）２００ｍｇを１１４００ｍｇの溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に溶解させた後、これにフェニルイソシアネート（東京化成工業株式会社製）４００ｍｇを添加し、９０℃で４時間撹拌して反応させた。これにより、デンプンのヒドロキシル基とフェニルイソシアネートのイソシアネート基とが反応して、フェニル基（機能性官能基）が、ウレタン結合を介して結合した修飾デンプン（修飾ヒドロキシル基含有ポリマー）を得た。修飾デンプンは、仕込み比から求めた修飾率（ヒドロキシル基が機能性官能基に変換された割合）が１００％であった。 [Production and evaluation of protein fiber]
Example 1
<Preparation of spinning dope>
After 200 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 11400 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), 400 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added thereto. And stirred at 90 ° C. for 4 hours for reaction. Thereby, the hydroxyl group of starch and the isocyanate group of phenyl isocyanate reacted, and modified starch (modified hydroxyl group-containing polymer) in which the phenyl group (functional functional group) was bonded via a urethane bond was obtained. In the modified starch, the modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio was 100%.
　反応液を室温まで冷却した後、上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末３００ｍｇを反応液に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。紡糸原液中の修飾デンプンの含有量は、修飾デンプンとデンプンの総含有量を基準として、１７質量％である。 After the reaction solution was cooled to room temperature, 300 mg of the modified fibroin (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred and dissolved at 90 ° C. for 12 hours to obtain a transparent spinning solution. The content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
＜タンパク質繊維の製造＞
　調製した紡糸原液と公知の乾湿式紡糸装置とを用いて乾湿式紡糸を行って、タンパク質繊維（フィブロイン繊維）を得た。なお、ここでは、乾湿式紡糸を下記の条件で行った。
　凝固液（メタノール）の温度：５～１０℃
　延伸倍率：６倍
　乾燥温度：８０℃ <Manufacture of protein fibers>
Dry and wet spinning was performed using the prepared spinning solution and a known dry and wet spinning device to obtain protein fibers (fibroin fibers). Here, dry and wet spinning was performed under the following conditions.
Coagulation liquid (methanol) temperature: 5-10 ° C
Stretch ratio: 6 times Drying temperature: 80 ° C
＜水収縮試験＞
　得られたタンパク質繊維を長さ約１０ｃｍに切断し、水への浸漬前の糸の長さ（ｃｍ）を測定した。次いで、糸を４０℃の水浴に１分間浸漬した。その後、糸を水浴から取り出して、１５分間室温で真空乾燥させた後、乾燥後の糸の長さを測定した。タンパク質繊維の水収縮率を以下の式に従って算出した。
　水収縮率（％）＝｛（浸漬前の長さ／浸漬・乾燥後の長さ）－１｝×１００ <Water shrinkage test>
The obtained protein fiber was cut into a length of about 10 cm, and the length (cm) of the yarn before immersion in water was measured. The yarn was then immersed in a 40 ° C. water bath for 1 minute. Thereafter, the yarn was taken out of the water bath and vacuum dried at room temperature for 15 minutes, and then the length of the dried yarn was measured. The water shrinkage rate of the protein fiber was calculated according to the following formula.
Water shrinkage (%) = {(length before dipping / length after dipping / drying) -1} × 100
（実施例２）
＜紡糸原液（ドープ液）の調製＞
　デンプン（和光純薬工業株式会社製）２５３ｍｇを７６００ｍｇの溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に溶解させた後、これに無水酢酸（和光純薬工業株式会社製）１４７ｍｇを添加し、９０℃で４時間撹拌して反応させた。これにより、デンプンのヒドロキシル基と無水酢酸とが反応して、アセチル基（機能性官能基）が結合した修飾デンプン（修飾ヒドロキシル基含有ポリマー）を得た。修飾デンプンは、仕込み比から求めた修飾率（ヒドロキシル基が機能性官能基に変換された割合）が１００％であった。 (Example 2)
<Preparation of spinning dope>
253 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), and then 147 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto. The mixture was added and stirred at 90 ° C. for 4 hours for reaction. Thereby, the hydroxyl group of starch reacted with acetic anhydride to obtain a modified starch (modified hydroxyl group-containing polymer) to which an acetyl group (functional functional group) was bonded. In the modified starch, the modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio was 100%.
　反応液を室温まで冷却した後、上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末２０００ｍｇを反応液に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。紡糸原液中の修飾デンプンの含有量は、修飾デンプンとデンプンの総含有量を基準として、１７質量％である。 After cooling the reaction solution to room temperature, 2000 mg of the modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution. The content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
（実施例３）
＜紡糸原液（ドープ液）の調製＞
　デンプン（和光純薬工業株式会社製）２１５ｍｇを７６００ｍｇの溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に溶解させた後、これに無水酢酸（和光純薬工業株式会社製）１８５ｍｇを添加し、９０℃で４時間撹拌して反応させた。これにより、デンプンのヒドロキシル基と無水酢酸とが反応して、アセチル基（機能性官能基）が結合した修飾デンプン（修飾ヒドロキシル基含有ポリマー）を得た。修飾デンプンは、仕込み比から求めた修飾率（ヒドロキシル基が機能性官能基に変換された割合）が５０％であった。 (Example 3)
<Preparation of spinning dope>
215 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), and then 185 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto. The mixture was added and stirred at 90 ° C. for 4 hours for reaction. Thereby, the hydroxyl group of starch reacted with acetic anhydride to obtain a modified starch (modified hydroxyl group-containing polymer) to which an acetyl group (functional functional group) was bonded. In the modified starch, the modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio was 50%.
　反応液を室温まで冷却した後、上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末２０００ｍｇを反応液に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。紡糸原液中の修飾デンプンの含有量は、修飾デンプンとデンプンの総含有量を基準として、１７質量％である。 After cooling the reaction solution to room temperature, 2000 mg of the modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution. The content of modified starch in the spinning dope is 17% by mass, based on the total content of modified starch and starch.
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
（実施例４）
＜紡糸原液（ドープ液）の調製＞
　ポリビニルアルコール（ＰＶＡ）（和光純薬工業株式会社製）１２８ｍｇを７６００ｍｇの溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に溶解させた後、これにフェニルイソシアネート（東京化成工業株式会社製）２７２ｍｇを添加し、９０℃で４時間撹拌して反応させた。これにより、ＰＶＡのヒドロキシル基とフェニルイソシアネートとが反応して、フェニル基（機能性官能基）が、ウレタン結合を介して結合した修飾ＰＶＡ（修飾ヒドロキシル基含有ポリマー）を得た。修飾ＰＶＡは、仕込み比から求めた修飾率（ヒドロキシル基が機能性官能基に変換された割合）が１００％であった。 (Example 4)
<Preparation of spinning dope>
After dissolving 128 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved therein. ) 272 mg was added and reacted at 90 ° C. for 4 hours with stirring. Thereby, the hydroxyl group of PVA and phenyl isocyanate reacted, and the modified PVA (modified hydroxyl group containing polymer) which the phenyl group (functional functional group) couple | bonded through the urethane bond was obtained. The modified PVA had a modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio of 100%.
　反応液を室温まで冷却した後、上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末２０００ｍｇを反応液に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。紡糸原液中の修飾ＰＶＡの含有量は、修飾ＰＶＡとＰＶＡの総含有量を基準として、１７質量％である。 After cooling the reaction solution to room temperature, 2000 mg of the modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution. The content of the modified PVA in the spinning dope is 17% by mass based on the total content of the modified PVA and PVA.
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
（実施例５）
＜紡糸原液（ドープ液）の調製＞
　ポリビニルアルコール（ＰＶＡ）（和光純薬工業株式会社製）１９３ｍｇを７６００ｍｇの溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に溶解させた後、これにフェニルイソシアネート（東京化成工業株式会社製）２０７ｍｇを添加し、９０℃で４時間撹拌して反応させた。これにより、ＰＶＡのヒドロキシル基とフェニルイソシアネートとが反応して、フェニル基（機能性官能基）が、ウレタン結合を介して結合した修飾ＰＶＡ（修飾ヒドロキシル基含有ポリマー）を得た。修飾ＰＶＡは、仕込み比から求めた修飾率（ヒドロキシル基が機能性官能基に変換された割合）が５０％であった。 (Example 5)
<Preparation of spinning dope>
After 193 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved therein. ) 207 mg was added and reacted at 90 ° C. with stirring for 4 hours. Thereby, the hydroxyl group of PVA and phenyl isocyanate reacted, and the modified PVA (modified hydroxyl group containing polymer) which the phenyl group (functional functional group) couple | bonded through the urethane bond was obtained. The modified PVA had a modification rate (ratio of hydroxyl groups converted to functional functional groups) determined from the charging ratio of 50%.
　反応液を室温まで冷却した後、上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末２０００ｍｇを反応液に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。紡糸原液中の修飾ＰＶＡの含有量は、修飾ＰＶＡとＰＶＡの総含有量を基準として、１７質量％である。 After cooling the reaction solution to room temperature, 2000 mg of the modified fibroin (PRT799) powder obtained above was added to the reaction solution and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution. The content of the modified PVA in the spinning dope is 17% by mass based on the total content of the modified PVA and PVA.
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
（比較例１）
＜紡糸原液（ドープ液）の調製＞
　上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末１２００ｍｇを溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。 (Comparative Example 1)
<Preparation of spinning dope>
1200 mg of the modified fibroin (PRT799) powder obtained above was added to a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl) and dissolved by stirring at 90 ° C. for 12 hours to obtain a transparent spinning solution. .
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
（比較例２）
＜紡糸原液（ドープ液）の調製＞
　上記で得た改変フィブロイン（ＰＲＴ７９９）の粉末３０００ｍｇ、及びデンプン（和光純薬工業株式会社製）６００ｍｇを溶媒（４重量％のＬｉＣｌを含むジメチルスルホキシド（ＤＭＳＯ））に添加し、９０℃で１２時間撹拌して溶解させ、透明な紡糸原液を得た。 (Comparative Example 2)
<Preparation of spinning dope>
3000 mg of the modified fibroin (PRT799) powder obtained above and 600 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a solvent (dimethylsulfoxide (DMSO) containing 4% by weight of LiCl), and the mixture was heated at 90 ° C. for 12 hours. The mixture was dissolved by stirring to obtain a transparent spinning solution.
＜タンパク質繊維の製造、及び水収縮試験＞
　調製した紡糸原液を使用して、実施例１と同様の手順でタンパク質繊維の製造、及び水収縮試験を実施した。 <Production of protein fiber and water shrinkage test>
Using the prepared spinning dope, production of protein fibers and a water shrinkage test were performed in the same manner as in Example 1.
　結果を図４及び表６に示す。
Figure JPOXMLDOC01-appb-T000006
 The results are shown in FIG.
Figure JPOXMLDOC01-appb-T000006
　機能性官能基として疎水性の官能基（フェニル基又はアセチル基）が結合した修飾ヒドロキシル基含有ポリマー（修飾デンプン又は修飾ＰＶＡ）と、タンパク質（改変フィブロイン）とを含む紡糸原液を用いてタンパク質繊維を製造することにより（実施例１～５）、タンパク質のみを含む紡糸原液を用いた場合（比較例１）、及びタンパク質と修飾されていないヒドロキシル基含有ポリマーとを含む紡糸原液を用いた場合（比較例２）と比べて、水収縮率が低減され、耐水性を有するタンパク質繊維が得られた。 Protein fibers using a spinning stock solution containing a modified hydroxyl group-containing polymer (modified starch or modified PVA) to which a hydrophobic functional group (phenyl group or acetyl group) is bonded as a functional functional group and a protein (modified fibroin) In the case of using a spinning stock solution containing only protein (Comparative Example 1) and using a spinning stock solution containing a protein and an unmodified hydroxyl group-containing polymer (Comparison 1) Compared with Example 2), the water shrinkage ratio was reduced, and a protein fiber having water resistance was obtained.

Claims (20)

  1. 　ヒドロキシル基含有ポリマーに機能性官能基が結合した修飾ヒドロキシル基含有ポリマーと、タンパク質と、を含む、タンパク質組成物。 A protein composition comprising a modified hydroxyl group-containing polymer in which a functional functional group is bonded to a hydroxyl group-containing polymer, and a protein.
  2. 　前記ヒドロキシル基含有ポリマーが多糖類である、請求項１に記載のタンパク質組成物。 The protein composition according to claim 1, wherein the hydroxyl group-containing polymer is a polysaccharide.
  3. 　前記多糖類がデンプンである、請求項２に記載のタンパク質組成物。 The protein composition according to claim 2, wherein the polysaccharide is starch.
  4. 　前記機能性官能基が、フェニル基又はアセチル基である、請求項１～３のいずれか一項に記載のタンパク質組成物。 The protein composition according to any one of claims 1 to 3, wherein the functional functional group is a phenyl group or an acetyl group.
  5. 　前記タンパク質が構造タンパク質である、請求項１～４のいずれか一項に記載のタンパク質組成物。 The protein composition according to any one of claims 1 to 4, wherein the protein is a structural protein.
  6. 　前記構造タンパク質がフィブロインである、請求項５に記載のタンパク質組成物。 The protein composition according to claim 5, wherein the structural protein is fibroin.
  7. 　前記フィブロインがクモ糸フィブロインである、請求項６に記載のタンパク質組成物。 The protein composition according to claim 6, wherein the fibroin is spider silk fibroin.
  8. 　前記タンパク質組成物が成形体である、請求項１～７のいずれか一項に記載のタンパク質組成物。 The protein composition according to any one of claims 1 to 7, wherein the protein composition is a molded body.
  9. 　前記成形体が繊維である、請求項８に記載のタンパク質組成物。 The protein composition according to claim 8, wherein the molded body is a fiber.
  10. 　溶媒を更に含み、
    　前記タンパク質組成物が、ドープ液である、請求項１～７のいずれか一項に記載のタンパク質組成物。     Further comprising a solvent,
    The protein composition according to any one of claims 1 to 7, wherein the protein composition is a dope solution.
  11. 　ａ）機能性官能基を有する反応剤とヒドロキシル基含有ポリマーとを反応させて、前記ヒドロキシル基含有ポリマーに前記機能性官能基が結合した修飾ヒドロキシル基含有ポリマーを得る工程と、
    　ｂ）前記修飾ヒドロキシル基含有ポリマーとタンパク質とを結合させる工程と、
    を備える、タンパク質組成物の製造方法。     a) reacting a reactive agent having a functional functional group with a hydroxyl group-containing polymer to obtain a modified hydroxyl group-containing polymer having the functional functional group bonded to the hydroxyl group-containing polymer;
    b) binding the modified hydroxyl group-containing polymer and protein;
    A method for producing a protein composition.
  12. 　前記ｂ）工程が、
    　ｂ－１）前記修飾ヒドロキシル基含有ポリマーと前記タンパク質と溶媒とを含むドープ液を得るステップと、
    　ｂ－２）前記ドープ液を脱溶媒剤に接触させて、該ドープ液から前記溶媒を離脱させることにより、前記タンパク質と前記修飾ヒドロキシル基含有ポリマーとを水素結合させるステップと、を含む、請求項１１に記載のタンパク質組成物の製造方法。     Step b)
    b-1) obtaining a dope solution comprising the modified hydroxyl group-containing polymer, the protein and a solvent;
    b-2) hydrogen bonding the protein and the modified hydroxyl group-containing polymer by bringing the dope solution into contact with a solvent removal agent to release the solvent from the dope solution. 11. A method for producing the protein composition according to 11.
  13. 　ｂ－２）ステップにおいて、
    　前記ドープ液から前記溶媒を離脱させることにより、前記タンパク質と前記修飾ヒドロキシル基含有ポリマーとを水素結合させると共に、前記タンパク質を凝固させて成形し、前記タンパク質と前記修飾ヒドロキシル基含有ポリマーとを含有する成形体を得ることを更に含む、請求項１２に記載のタンパク質組成物の製造方法。     In step b-2)
    By desorbing the solvent from the dope solution, the protein and the modified hydroxyl group-containing polymer are hydrogen-bonded, and the protein is coagulated and molded to contain the protein and the modified hydroxyl group-containing polymer. The method for producing a protein composition according to claim 12, further comprising obtaining a molded body.
  14. 　前記成形体が繊維である、請求項１３に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to claim 13, wherein the molded body is a fiber.
  15. 　前記ヒドロキシル基含有ポリマーが多糖類である、請求項１１～１４のいずれか一項に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to any one of claims 11 to 14, wherein the hydroxyl group-containing polymer is a polysaccharide.
  16. 　前記多糖類がデンプンである、請求項１５に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to claim 15, wherein the polysaccharide is starch.
  17. 　前記機能性官能基を有する反応剤が、機能性官能基を有するイソシアネートである、請求項１１～１６のいずれか一項に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to any one of claims 11 to 16, wherein the reactive agent having a functional functional group is an isocyanate having a functional functional group.
  18. 　前記タンパク質が構造タンパク質である、請求項１１～１７のいずれか一項に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to any one of claims 11 to 17, wherein the protein is a structural protein.
  19. 　前記構造タンパク質がフィブロインである、請求項１８に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to claim 18, wherein the structural protein is fibroin.
  20. 　前記フィブロインがクモ糸フィブロインである、請求項１９に記載のタンパク質組成物の製造方法。 The method for producing a protein composition according to claim 19, wherein the fibroin is spider silk fibroin.
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