Method for producing insolubilized molded article having reduced swelling-shrinkage rate

Abstract

The present invention provides a molded article having a reduced swelling-shrinkage rate, and a method for producing said molded article.　More specifically, provided are a stretching method including a thermal stretching step for stretching under specific conditions of temperature and stretching speed, and a method for producing a molded article having a reduced swelling-shrinkage rate using said stretching method.

Description

Method for manufacturing insolubilized molded products with reduced swelling and shrinkage rates

[0001] The present invention relates to a method for producing an insolubilized molded article with reduced swelling and shrinkage, an insolubilized molded article, and a stretching method.

[0002] Synthetic resins, such as plastics, are used in every aspect of human society and have become indispensable materials for modern life. However, on the other hand, problems such as global warming caused by the large amount of carbon dioxide released when they are burned, and environmental pollution from waste plastics such as microplastics due to their chemical stability and lack of biodegradability, have become apparent.

[0003] Therefore, in recent years, in order to realize a sustainable society, there has been a demand for the development of environmentally friendly and safe alternatives to synthetic resins made from fossil fuels. Polypeptide molded products, for example, are one such alternative.

[0004] Fibroin protein is attracting attention as a raw material for polypeptide molded products. Fibroin protein is a fiber component of silkworm silk and spider silk (dragging silk), and because it has a β-sheet structure as its crystalline structure, it exhibits high toughness with an excellent balance of strength and elongation. Furthermore, because it is composed of polypeptides, it is biodegradable and highly biocompatible. Moreover, by molding polypeptides, it becomes possible to provide products that possess the excellent properties of natural silk and spider silk, as well as shapes that could not be produced from natural threads, such as films and fibers of different thicknesses. For this reason, polypeptide molded products using fibroin protein as a raw material are expected to be used as materials in a wide range of fields, such as medical materials and structural materials.

[0005] Generally, when processing proteins into polypeptide molded products, liquid protein is used as the raw material. In the case of fibroin protein (mainly fibroin H-chain protein), liquid fibroin protein stored in the silk glands of silkworms and other organisms before fiber formation, or liquid fibroin protein obtained by expressing it in E. coli and other organisms using genetic engineering technology, can be used as the raw material. In addition, an aqueous solution of fibroin protein, obtained by dissolving already fiber-formed solid fibroin protein in a solvent to make it liquid, can also be used as the raw material. Products obtained by re-coagulating and molding an aqueous solution of fibroin protein are called regenerated fibroin proteins, and due to their ease of processing and high versatility, they are expected to have applications in various fields (Non-patent documents 1 and 2).

[0006] Kim HH, et al., 2016, Polymer, 90: 26-33.Guo C., et al. 2020, Biomacromolecules, 21: 1678-1686.

[0007] Thus, while the usefulness of regenerated fibroin proteins (including artificial fibroin proteins) is attracting attention, there are also challenges that were not anticipated with natural fibroin fibers.

[0008] One such challenge is the problem of swelling and shrinkage (used synonymously with wet shrinkage or dimensional change) when wet and dried. When the swelling and shrinkage rate is high, for example, dimensions may change due to washing and drying, or after use in a humid environment (such as during surgery), or dimensions may change depending on the weather in places exposed to wind and rain, thus limiting the applicable fields depending on its properties. Although methods such as pre-swelling and shrinking after stretching before provision are known to solve the problem of swelling and shrinkage during use, pre-swelling and shrinkage is undesirable because it greatly impairs the physical properties of the fiber, including strength. Therefore, in order to make the most of the great potential of fibroin protein, it is desirable to suppress the swelling and shrinkage rate in molded products without going through the swelling and shrinkage process.

[0009] However, in practice, regardless of the type of raw fibroin protein, the swelling shrinkage rate of molded articles of fibroin protein tends to be high. For example, even for Bombyx mori fibroin protein, which exhibits a low swelling shrinkage rate of about 3% in natural silk, and bagworm moth fibroin protein, which exhibits an extremely low swelling shrinkage rate of less than 3% in natural silk, molded articles exhibit a high swelling shrinkage rate of about 20%.

[0010] Regarding fibroin proteins that exhibit different swelling shrinkage rates in natural silk, forming a molded article tends to uniformly increase the swelling shrinkage rate, so the high swelling shrinkage rate of molded articles is highly likely to be caused by treatment in the production process.

[0011] Therefore, an object of the present invention is to provide a molded article with reduced swelling shrinkage rate and a production method based on contrivance of the treatment method up to the completion of stretching thereof.

[0012] As a result of intensive studies conducted by the present inventors to solve the above problem, they have found that the swelling shrinkage rate can be significantly reduced by performing stretching at a specific speed under specific temperature conditions.

[0013] The present invention is based on the above novel finding and the like, and provides the following. [1] A method for producing an insolubilized polypeptide molded article, wherein a coagulated molded article derived from a solution containing a polypeptide has a stretching heat constant V represented by formula I h The production method, comprising a hot stretching step of stretching under a condition of 500°C·mm / s or higher. [Mathematical 1] V h = (T s - 145) × V s (I) (In the formula, T s represents the temperature during stretching, and V s represents the stretching speed during stretching) [2] The production method according to [1], wherein the stretching heat constant V h is 600°C·mm / s or more and 18000°C·mm / s or less. [3] The production method according to [1] or [2], wherein the temperature T during stretching s is 150°C or higher and 250°C or lower. [4] The stretching speed V during stretching sA method for manufacturing according to [1] or [2], wherein the stretching ratio in the heat stretching step is 30 mm / s or more and 150 mm / s or less. [5] A method for manufacturing according to any one of [1] to [4], wherein the stretching ratio in the heat stretching step is 3 times or more and 7 times or less. [6] A method for manufacturing according to any one of [1] to [5], wherein the stretching is wet stretching. [7] A method for manufacturing according to any one of [1] to [6], further comprising a coagulation step in which a solution containing polypeptide is coagulated by a desolvent treatment before the heat stretching step to produce a coagulated molded product. [8] A method for manufacturing according to any one of [1] to [7], wherein the polypeptide contains fibroin protein. [9] A method for manufacturing according to [8], wherein the fibroin protein is derived from bagworm silk.

[10] A method for manufacturing according to any one of [1] to [9], wherein the polypeptide insolubilized molded product is a stretched yarn.

[11] A fibroin insolubilized molded product made from a fibroin protein solution as a raw material, having a swelling shrinkage rate of 19% or less.

[12] A polypeptide insolubilized molded product manufactured by a method for manufacturing according to any one of [1] to

[10] .

[13] A method for stretching a solidified molded article derived from a polypeptide solution, wherein the solidified molded article is given a heat extension constant V shown in formula I. h The stretching method, comprising a heat stretching step in which the material is stretched under conditions of 500°C・mm / s or higher. [Equation 2] V h = (T s -145) × V s (I) (where T s V indicates the temperature during stretching. s (wherein indicates the stretching speed during stretching)

[14] The stretching method according to

[13] , wherein the polypeptide comprises a fibroin protein.

[0014] According to the manufacturing method of the present invention, it is possible to produce an insolubilized molded article with a reduced swelling and shrinkage rate.

[0015] Figure 1 shows the stretching temperature T. s (°C) and stretching speed V s This figure shows the relationship between (mm / s) and swelling / shrinkage rate (%). In the figure, the white circle shows the data under the conditions where its center is located, the number inside the white circle represents the swelling / shrinkage rate, and the radius of the white circle reflects the magnitude of the swelling / shrinkage rate. Figure 2 shows the thermal constant V hIt is a diagram showing the relationship between (°C・mm / s) and swelling shrinkage (%). In the figure, the dots represent individual data points, the mathematical formula represents the equation of the approximate straight line, and "R 2 " represents R of the approximate straight line 2 value.

[0016] 1. Stretching method for polypeptide coagulated molded articles 1-1. Overview A first aspect of the present invention is a stretching method for a polypeptide coagulated molded article. The method of this aspect includes a hot stretching step as an essential step and a coagulation step as an optional step. According to the method of this aspect, a molded article with reduced swelling and shrinkage can be provided without going through a swelling and shrinkage process.

[0017] 1-2. Definitions Terms used in the present specification are defined below. As used herein, the term "molded article" refers to a solid body that has a certain hardness and a specific shape. It is preferably subjected to molding processing, but may be in an unformed state. "Solid body" refers to a solid substance other than liquids and gases. As used herein, the term also includes semi-solid substances such as gels.

[0018] As used herein, the term "coagulated molded article" refers to an un insolubilized polypeptide molded article obtained by coagulating a polypeptide solution, for example, by desolvation or the like.

[0019] "Coagulation" refers to a change from a liquid state to a solid state, that is, solidification.

[0020] As used herein, the term "insolubilized molded article" refers to an insolubilized regenerated polypeptide molded article obtained by coagulating a polypeptide solution, for example, by desolvation or the like. As used herein, the term corresponds to a polypeptide molded article obtained by subjecting a polypeptide coagulated molded article to an insolubilization treatment.

[0021] As used herein, the term "insolubilization treatment" refers to a treatment for insolubilizing a regenerated polypeptide. Specific examples of the insolubilization treatment include, but are not limited to, heat treatment, alcohol treatment, stretching treatment, or combinations thereof.

[0022] As used herein, the term "regenerated polypeptide" refers to a product obtained by coagulating a liquid polypeptide dissolved in an aqueous solution and regenerating it as a solid polypeptide. As used herein, this term applies to, for example, regenerated fibrous protein and regenerated fibroin protein.

[0023] As used herein, the term "regenerated fibroin" refers to a product obtained by coagulating liquid fibroin dissolved in an aqueous solution and regenerating it as solid fibroin. As used herein, this term mainly applies to regenerated fibroin heavy chain protein regenerated from an aqueous solution of fibroin heavy chain protein.

[0024] As used herein, the term "regenerated fibroin molded article" refers to a solidified fibroin molded article or an insolubilized fibroin molded article obtained by molding regenerated fibroin to have a certain hardness and a specific shape. Examples thereof include thin film molded articles, fine particle molded articles, and fiber molded articles.

[0025] As used herein, the term "stretching" refers to stretching a solidified molded article to change the orientation state and crystallization state of peptide chains in the solidified molded article.

[0026] As used herein, the term "stretching speed" refers to the difference between the delivery speed and the pulling speed during stretching. The pulling speed is typically a winding speed. When the action (rotation) directions of delivery and pulling are opposite, one speed is regarded as a negative delivery speed, and the difference between this speed and the other speed (pulling speed) is treated as the stretching speed.

[0027] As used herein, the term "wet stretching" refers to a stretching method performed by stretching a solidified molded article immersed in a liquid. Wet stretching as used herein broadly refers to a stretching method performed by applying heat to the solidified molded article via a liquid.

[0028] As used herein, the term "dry stretching" refers to a stretching method performed by stretching a solidified molded article in an atmosphere.

[0029] In this specification, "swelling shrinkage" refers to the process in which an immobilized molded product swells in the short axis direction and shrinks in the long axis direction as moisture penetrates and is lost from the interior of the product. Typically, shrinkage in the long axis direction corresponds to swelling shrinkage in this specification. "Swelling shrinkage rate" refers to the percentage by which an immobilized molded product shrinks due to swelling shrinkage. Typically, it is the value obtained by dividing the difference in the long axis length before and after swelling shrinkage by the long axis length before swelling shrinkage. If the immobilized molded product is a planar shape such as a film, the dimensional change rate can be used as the swelling shrinkage rate in this specification. The method for measuring the dimensional change rate is not particularly limited, but for example, it can be measured by Method A (room temperature water immersion method) of JIS L 1096.

[0030] The polypeptide-insolubilized molded article described herein is composed of polypeptides contained in the raw material solution of the coagulated molded article. The type of polypeptide is not particularly limited, as long as it is a polypeptide that can be subjected to molding by stretching. Preferably, it is a fibrous protein.

[0031] "Fibrous proteins" refer to insoluble simple proteins that have a long, fibrous structure in their three-dimensional form.

[0032] With respect to proteins and polypeptides, "insoluble" means having a three-dimensional structure that does not dissolve in water or aqueous solutions. The three-dimensional structure of an insoluble protein and / or polypeptide can be dissolved by solubilization treatment, converting it back to its water-soluble form before it formed its three-dimensional structure.

[0033] Specific examples of fibrous proteins include fibroin (including spirulin), keratin, collagen, elastin, myosin, laminin, fibrin, or mutant fibroin proteins thereof. For example, fibroin protein or mutant fibroin protein thereof can be suitably used.

[0034] "Fibroin protein" refers to the silk protein that makes up silk threads derived from insects such as silkworms and bagworms. When simply referred to as fibroin protein, it includes both wild-type and mutant varieties. In this specification, when "fibroin protein" is used, it refers to fibroin H-chain protein unless otherwise specified.

[0035] "Fibroin H-chain protein" (often abbreviated as "FibH" herein) is the main protein constituting the fibroin complex (silk fibroin elementary unit; SFEU complex), which is the fibrous protein component of silk thread. Generally, FibH refers to the high molecular weight fibrous protein that makes up silk thread derived from insects such as silkworms and bagworms. However, in this specification, spidoin protein, which is a high molecular weight fibrous protein that makes up silk thread, particularly the dragline silk, derived from organisms of the order Araneae or Acari, is also included in the definition of FibH in the following description. FibH usually has an amino acid sequence in which clusters of glycine residues (G) and alanine residues (A) are repeated. In this specification, FibH may be natural FibH or artificial FibH.

[0036] In this specification, "natural fibroin H-chain protein" (natural FibH) refers to FibH that exists in nature. Natural FibH is defined as a protein whose full-length amino acid sequence is identical to that of naturally occurring FibH. Regardless of the collection process, any single molecule of FibH whose composition is identical to that of naturally occurring FibH is included in the definition of natural FibH. Examples include FibH directly collected from bagworms, silkworms, or spiders, or FibH obtained through the expression of the FibH gene. Since natural FibH is a protein encoded by the wild-type FibH gene of various organisms, it is often referred to as "wild-type FibH" in this specification.

[0037] Generally, natural fibroin heavy chain proteins (natural FibH) consist of the N-terminal region, the central region, and the C-terminal region as basic components, in that order from the N-terminus.

[0038] The "N-terminal region" refers to the region in the amino acid sequence that constitutes natural FibH that is located on the N-terminal side of the central region described below, does not contain repeating units, and consists of 70 to 250 amino acid residues.

[0039] Furthermore, the "central region" is the main region that exhibits the physical properties of natural FibH. This region is responsible for the fibrous properties of FibH and is composed of multiple repeating units consisting of the same and / or different amino acid sequences linked together. A "repeating unit" is the main constituent unit of the central region, and one repeating unit can contain multiple glycine (G) and alanine (A) molecules. Therefore, more than 70% of the amino acid sequence of the central region is composed of glycine and alanine.

[0040] Furthermore, the "C-terminal region" refers to the region in the amino acid sequence that constitutes natural FibH that is located on the C-terminal side of the central region, does not contain repeating units, and consists of 30 to 60 amino acid residues.

[0041] The fibroin protein may be wild-type fibroin protein or mutant fibroin protein.

[0042] In this specification, "wild-type fibroin protein" refers to naturally occurring fibroin protein encoded by the wild-type silk protein gene of various organisms.

[0043] In this specification, "mutant fibroin protein" refers to a silk protein in which all or part of a wild-type fibroin protein has been artificially modified by genetic engineering or other means. It consists of an amino acid sequence different from that of wild-type fibroin protein and, in principle, is a fibroin protein that does not exist in nature. However, it is assumed that mutant fibroin proteins include the N-terminal region, the central region, and the C-terminal region, in order from the N-terminus, which are the basic components of wild-type fibroin protein. Examples of mutant silk proteins include fibroin proteins in which one or more amino acids have been added, deleted, and / or substituted into the amino acid sequence of a fibroin protein, and chimeric fibroin proteins (hybrid fibroin proteins) in which the amino acid sequences of fibroin proteins from two or more different insects have been fused. Mutant fibroin proteins may have the same physical properties as wild-type fibroin proteins or they may have different physical properties.

[0044] In this specification, "artificial fibroin protein" refers to fibroin proteins that do not exist in nature, and typically includes mutant fibroin proteins.

[0045] In this specification, "artificial fibroin H-chain protein" (artificial FibH) refers to FibH that does not exist in nature. It is a fibroin H-chain protein in which all or part of natural FibH has been artificially modified using genetic engineering technology or the like.

[0046] In this specification, "mutant fibroin H-chain protein" (often referred to as "mutant FibH" in this specification) is FibH composed of an amino acid sequence different from that of wild-type FibH, and is synonymous with artificial FibH in this specification. Whether or not the FibH has the same physical properties as wild-type FibH is irrelevant. Examples of mutant FibH include mutant FibH obtained by introducing the addition, deletion, and / or substitution of one or more amino acids into the amino acid sequence of FibH, and chimeric FibH (hybrid FibH) obtained by fusing the amino acid sequences of FibH from two or more different insect species.

[0047] The amino acid sequence of the mutant fibroin protein is not particularly limited, but examples include a protein consisting of an amino acid sequence in which one or more amino acids are added, deleted, or substituted in the amino acid sequence of the wild-type fibroin protein, or a protein consisting of an amino acid sequence having 90% or more, preferably 95% or more, more preferably 96% or more, 97% or more, 98% or more, or 99% or more amino acid identity with the wild-type amino acid sequence.

[0048] In this specification, "amino acid identity" refers to the percentage of identical amino acids in one polypeptide relative to the total number of amino acids in the other polypeptide, after the amino acid sequences of two polypeptides have been aligned and, if necessary, gaps have been introduced into either amino acid sequence to maximize the degree of amino acid agreement between the two polypeptides. This percentage of amino acid identity can be easily determined using known programs such as the homology search program BLAST (Basic local alignment search tool; Altschul, SF et al, J. Mol. Biol., 215, 403-410, 1990).

[0049] The species from which fibroin proteins are derived in this specification are not particularly limited. For example, species belonging to the silkworms may be included.

[0050] In this specification, "silky organisms" refers to a general term for organisms that have silk glands and are capable of spinning or secreting silk. Examples include silkworms and organisms belonging to the order Araneae.

[0051] In this specification, "silkworm" refers to a general term for insects that possess silk glands and are capable of spinning silk. Specifically, it refers to species from the orders Lepidoptera, Hymenoptera, Neuroptera, Trichoptera, etc., that are primarily capable of spinning silk during the larval stage for nesting, cocooning, or migration. Silkworms are defined as insects that are capable of spinning silk, and include those that spin silk at any stage of development, such as larvae and adults. For example, in the order Lepidoptera, this includes species belonging to families such as Bombycidae, Saturniidae, Psychidae, Brahmaeidae, Eupterotidae, Lasiocampidae, Archtiidae, and Noctuidae, which are capable of spinning large amounts of silk. Specifically, for example, silkworms (B. mori) and mulberry silkworms (B. mandarina) belonging to the genus Bombyx, the pearl silkworm (S. cynthia) and the Eri silkworm (S. cynthia ricini) belonging to the genus Samia, the Japanese oak silkworm (A. yamamai) and the Japanese silkworm (A. pernyi) belonging to the genus Antheraea, and the small Japanese oak silkworm (S. yamamai) belonging to the genus Saturnia. This includes species belonging to the genera Acanthopsyche, Anatolopsyche, Bacotia, Bambalina, Canephora, Chalioides, Dahlica, Diplodoma, Eumeta, Eumasia, Kozhantshikovia, Mahasena, Nipponopsyche, Paranarychia, Proutia, Psyche, Pteroma, Siederia, Striglocyrbasia, Taleporia, Theriodopteryx, and Trigonodoma, which are all members of the Psychidae family. In particular, silkworms, which are the larvae of the silkworm moth, and bagworms, which are the larvae of moths belonging to the Psychidae family, are suitable as silkworms. Specific examples of bagworm moths include the giant bagworm moth (Eumeta japonica), the small bagworm moth (Eumeta minuscula), and the moss bagworm moth (Nipponopsyche fuscescens).

[0052] Examples of organisms belonging to the order Araneae include species belonging to the families Araneidae, Nephilidae, Tetragnathidae, Theridiidae, and Linyphiidae. Specific examples include the Araneus genus species Araneus ventricosus, Araneus uyemurai, Araneus diadematus, and Araneus maccacus; the Argiope genus Araneus amoena; the Caerostris genus Caerostris darwini; and the Nephila genus Nephila species Nephila clavata, Nephila clavipes, and Nephila pilipes.

[0053] In this specification, fibrous proteins such as those derived from silkworm silk, spider silk, and bagworm silk can be suitably used.

[0054] In this specification, "bagworm silk" refers to silk derived from bagworms.

[0055] In this specification, "silk" refers to protein-based threads derived from insects and spiders, which are spun by their larvae and adults for purposes such as nesting, movement, anchoring, cocooning, and prey capture. The term "silk" in this specification includes monofilaments, spun fibers, and aggregated fibers.

[0056] In this specification, "spun silk fibers" refer to silk threads in their spun state in the case of bagworms and silkworms, and threads in their secreted state in the case of spiders. The spinned silk fibers of bagworms and silkworms are composed of difilaments, which are pairs of two single fibers. This form is based on the fact that during spinning, two single fibers extruded from the silk thread sacs located on the left and right sides of the bagworm or silkworm, through the spinning opening, are bound together by a sericin-like adhesive substance.

[0057] In this specification, "single fiber" refers to the smallest unit of fiber components, a filament, and is also called a monofilament. Single fibers are mainly composed of fibroin-like proteins that make up silk threads. When a spun fiber is composed of multiple single fibers, for example, adhesive substances can be removed by scouring the spun fiber to obtain single fibers.

[0058] In this specification, "composite fiber" refers to a fiber composed of multiple fiber bundles, also known as a multifilament. This is so-called raw silk, and in principle is composed of multiple single fibers, but in this specification, it also includes cases where it is composed of multiple single fibers and spinning fibers, or multiple spinning fibers. Composite fibers in this specification also include mixed fibers made by mixing multiple types of silk yarn (for example, multiple types of bagworm silk; multiple types of silkworm silk; multiple types of spider silk; silk composed of two or more of bagworm silk, silkworm silk, and spider silk). Composite fibers in this specification include not only twisted yarn fibers but also untwisted yarn fibers.

[0059] Silk threads can include scaffolding silks and nesting silks, but in this specification, silk threads include both. "Scaffolding silks" are silk threads spun or secreted by insects or spiders for movement, and they function as scaffolding to prevent them from falling from branches, leaves, etc., during movement. "Nesting silks," on the other hand, are silk threads that make up nests, and are spun or secreted to bind leaf fragments or twig fragments together, or to construct the nest or the inner wall of the nest, which is the living area.

[0060] Specific examples of fibroin proteins include α-helix-β-turn / sheet coexisting fibroin H-chain proteins such as the bagworm fibroin H-chain protein.

[0061] In this specification, "α-βt / s coexisting FibH (α-helix-β-turn / sheet coexisting fibroin H-chain protein)" refers to a fibroin H-chain protein characterized by containing one or more α-helix-forming sequences and β-turn-forming sequences in a single FibH molecule. Due to this characteristic, α-βt / s coexisting FibH has the property of allowing α-helix and β-turn to coexist in stable molecular forms within the peptide chain in aqueous solution, and allowing α-helix and β-sheet structures to coexist in stable molecular forms within the peptide chain in polypeptide coagulated molded products.

[0062] An "α-helix" is a secondary structure in polypeptides that forms a right-handed helical structure. The pitch per helix is ​​0.54 nm, and hydrogen bonds are formed between the imino group of the first amino acid residue and the carbonyl group of the fourth amino acid residue in a peptide chain of four consecutive amino acid residues, with 3.6 amino acid residues per turn.

[0063] In this specification, "β-turn" refers to a secondary structure in polypeptides in which a single molecular chain is bent and forms a sheet structure through intramolecular hydrogen bonding.

[0064] A "β-sheet structure" is a secondary structure in polypeptides in which at least two to three parallel β-chains (β-strands) are bonded laterally by intermolecular hydrogen bonds, forming a pleated sheet structure that is twisted as a whole. Substances that have a β-sheet structure within their molecule may be insoluble in water.

[0065] In this specification, "α-helix-forming sequence" refers to an amino acid sequence that, in whole or in part, forms an α-helix in an aqueous solution or a polypeptide coagulated molded article. For example, an amino acid sequence represented by (A)n (where n is an integer ≥ 6) is an example, specifically the amino acid sequence shown in Sequence ID No. 1. Another example is an amino acid sequence represented by (GGX)n (where X is an alanine residue (A) or a tyrosine residue (Y), and n is an integer ≥ 1) is an example, specifically the amino acid sequence shown in Sequence ID No. 2. The helix formed by (GGX)n corresponds to a "31-helix," which has a helix pitch slightly longer than that of an α-helix, but in this specification, the "31-helix" is also included as a structure of the α-helix.

[0066] In this specification, "β-turn-forming sequence" refers to an amino acid sequence that, in whole or in part, forms a β-turn in an aqueous solution, and in whole or in part, forms a β-sheet structure in a polypeptide coagulated molded product. Thus, this β-turn-forming sequence can form different secondary structures in an aqueous solution and in a polypeptide coagulated molded product. Examples of amino acid sequences exhibiting such characteristics include the amino acid sequence represented by (GX)n (where X is an alanine residue (A) or a serine residue (S), and n is an integer ≥ 3), specifically the amino acid sequence shown in Sequence ID No. 3. Also, the amino acid sequence represented by (GAGAGX)n (where X is a serine residue or a tyrosine residue, and n is an integer ≥ 1), specifically the amino acid sequence shown in Sequence ID No. 4. However, exceptionally, in the wild-type silkworm fibroin H chain protein, the (GX)n and (GAGAGX)n sequences do not form a β-sheet structure in the polypeptide coagulated molded product, but instead form a water-soluble crystalline structure consisting of an aggregate of β-turns called the Silk-I type.

[0067] α-βt / s coexisting FibH is defined as having at least one α-helix-forming sequence and one β-turn-forming sequence in its amino acid sequence, regardless of their position or number. For example, in the amino acid sequence of α-βt / s coexisting FibH, the α-helix-forming sequences and β-turn-forming sequences may be arranged in separate, consecutive clusters, or they may be arranged in alternating consecutive sequences. Furthermore, the α-helix-forming sequences and β-turn-forming sequences may be randomly distributed within the amino acid sequence of α-βt / s coexisting FibH.

[0068] In natural FibH, the α-helix-forming sequence and the β-turn-forming sequence may be contained within the repeating unit of the central region, or they may be contained outside of the repeating unit, such as the N-terminal region and / or the C-terminal region.

[0069] An example of artificial FibH having a structure in which α-βt / s coexist is mutant bagworm FibH.

[0070] In this specification, "mutant bagworm fibroin H chain protein (mutant bagworm FibH)" refers to a mutant FibH based on bagworm FibH, which is a mutant FibH obtained by introducing amino acid mutations into the amino acid sequence of wild-type bagworm FibH, and / or a chimeric FibH obtained by fusing the amino acid sequences of two or more different insects, including bagworms, and which has the structure of α-βs / t coexisting FibH.

[0071] Mutant bagworm FibH contains one or more repeat units in its amino acid sequence. Examples of specific amino acid sequences that constitute one repeat unit in bagworm FibH include the amino acid sequences shown in SEQ ID NOs. 5-13, amino acid sequences in which one or more amino acids are added, deleted, or substituted in the amino acid sequences shown in SEQ ID NOs. 5-13, or amino acid sequences that have 90% or more, 93% or more, 95% or more, 97% or more, 98% or more, or 99% or more amino acid identity with the amino acid sequences shown in SEQ ID NOs. 5-13 are amino acid sequences of repeat units unique to wild-type bagworm FibH of the giant bagworm moth, which has the α-βt / s coexisting FibH configuration.

[0072] Specific examples of mutant bagworm FibH include the amino acid sequence shown in SEQ ID NO: 14, which contains four repeat units consisting of the amino acid sequences shown in SEQ ID NOs: 5 to 13; the amino acid sequence in which one or more amino acids are added, deleted, or substituted in the amino acid sequence shown in SEQ ID NO: 14; or the amino acid sequence having 90% or more amino acid identity with the amino acid sequence shown in SEQ ID NO: 14. The amino acid sequence shown in SEQ ID NO: 14 is an amino acid sequence consisting of a part of the wild-type bagworm FibH of the giant bagworm moth.

[0073] An example of a specific base sequence that encodes the amino acid sequence shown in Sequence ID No. 14 is the base sequence shown in Sequence ID No. 15.

[0074] As mutant or artificial fibroin proteins, chimeric (hybrid) fibroin proteins can be used, which are a combination of fibroin protein from one species and fibroin protein from another species. For example, chimeric FibH can be used, which is a combination of FibH from a bagworm and FibH from another insect. A specific example of such a chimeric FibH is the bagworm FibH of the giant bagworm moth and the silkworm FibH, which consists of the amino acid sequence shown in Sequence ID No. 22. In this chimeric FibH, positions 1 to 153 and 466 to 524 are amino acid sequences derived from the silkworm FibH, and positions 156 to 463 contain amino acid sequences derived from the giant bagworm FibH. In the case of chimeric FibH, it may possess the physical properties of the FibH of each of the species from which it is derived. Furthermore, FibH may consist of an amino acid sequence in which one or more amino acids are added, deleted, and / or substituted in the amino acid sequence shown in SEQ ID NO: 14, or an amino acid sequence having 90% or more amino acid identity with the amino acid sequence shown in SEQ ID NO: 22. An example of a specific nucleotide sequence encoding the amino acid sequence shown in SEQ ID NO: 22 is the nucleotide sequence shown in SEQ ID NO: 23.

[0075] Another example of a mutant bagworm FibH is a terminal mutant bagworm FibH, which contains a mutation in either the N-terminal region, the C-terminal region, or both of the wild-type bagworm FibH.

[0076] The aforementioned mutation, if it is a deletion, may involve the complete deletion of either the N-terminal region or the C-terminal region, or both, or a partial deletion. Here, "partial" refers to one or two or more consecutive or discontinuous amino acids from the amino acid sequence constituting a specific amino acid region (here, the N-terminal region and / or C-terminal region), and less than the total number of amino acids. Preferably, this corresponds to the number of amino acids that may cause loss of function in the terminal region. For example, this could include 5, 8, 10, 12, 15, 18, or 20 or more consecutive or discontinuous amino acids. In the terminal mutant bagworm FibH, either the N-terminal region or the C-terminal region, or both, may be deleted.

[0077] In addition to deletions, mutations may also include the addition or substitution of one or more amino acids. The amino acids to be added or substituted are not particularly limited, but amino acids that may lose the function of their terminal region are preferred.

[0078] Specific examples of terminal region mutant bagworm FibH include the amino acid sequences shown in SEQ ID NOs: 16-18. SEQ ID NO: 16 is the amino acid sequence of terminal region mutant bagworm FibHΔC, which is a mutant bagworm FibH having the amino acid sequence shown in SEQ ID NO: 14, but with the entire C-terminal region deleted. SEQ ID NO: 17 is the amino acid sequence of terminal region mutant bagworm FibHΔN, which is a mutant bagworm FibH having the amino acid sequence shown in SEQ ID NO: 14, but with the entire N-terminal region deleted. SEQ ID NO: 18 is the amino acid sequence of terminal region mutant bagworm FibHΔN / C, which is a mutant bagworm FibH having the amino acid sequence shown in SEQ ID NO: 14, but with both the N-terminal and C-terminal regions completely deleted. Furthermore, for example, the protein may be one in which the terminal region of the mutant bagworm FibH is deleted. Examples of such proteins include the terminal-region mutant bagworm FibHΔC, which has the amino acid sequence shown in SEQ ID NO: 24 and has the entire C-terminal region deleted.

[0079] Examples of specific base sequences of genes encoding terminal region mutant bagworm FibH include the terminal region mutant bagworm FibHΔC gene shown in SEQ ID NO: 19, the terminal region mutant bagworm FibHΔN gene shown in SEQ ID NO: 20, and the terminal region mutant bagworm FibHΔN / C gene shown in SEQ ID NO: 21.

[0080] Polypeptides such as fibrous proteins in this specification may be produced by the organism from which they originate, synthesized by other means, or a combination thereof. For example, methods other than those of which the polypeptide originates include chemical synthesis and synthesis by organisms other than the organism from which the polypeptide originates (including cells and microorganisms).

[0081] In this specification, "microorganism" refers to a single-celled organism, encompassing both eukaryotic single-celled organisms (such as yeast) and prokaryotes. Typically, prokaryotes are included. The type of microorganism is not limited; any microorganism commonly used in the field of genetic engineering is acceptable. For example, Escherichia coli is suitable. Unless otherwise specified, in this specification, "microorganism" refers to a transformed organism (genetically modified microorganism) that has been made capable of expressing the target polypeptide through genetic engineering.

[0082] 1-3. Process The method of this embodiment includes a heat stretching process as an essential process, and a solidification process and a pre-molding process as optional processes. Each process will be described below.

[0083] 1-3-1. Solidification Step This step is an optional step of the method according to this embodiment, and is a step of preparing a solidified molded product from a solution containing polypeptide.

[0084] The coagulation method is not particularly limited, as long as it can make polypeptides such as fibrous proteins (e.g., fibroin proteins) visible as solids. For example, any coagulation method known in the art can be used. Examples include desolvation treatment, exposure to a coagulant, and changes in solvent composition (ionic strength, salt concentration, pH, etc.).

[0085] In this specification, "solvent removal treatment" refers to a process of removing a solvent (e.g., water) from a doping solution in order to coagulate a polypeptide. Specific solvent removal treatments are not limited, but drying is one example.

[0086] "Doping solution" refers to a solution in which the raw material polymer is dissolved. In this specification, "doping solution" specifically refers to a solution in which polypeptides (such as fibroin proteins) that serve as raw materials for polypeptide-insolubilized molded articles are dissolved as raw material polymers. In this specification, "doping solution" is used synonymously with "solution containing polypeptides."

[0087] The drying method is not particularly limited, as long as it can reduce the amount of solvent in the doping solution. Examples include natural drying by exposure to the outside air, dehumidification drying by sealing in a sealed container with a desiccant, sun drying, ventilation drying by blowing hot air, heat drying, far-infrared drying, low-temperature drying, moist drying while maintaining humidity, vacuum drying by degassing, freeze-drying, or a combination thereof. All of these techniques are well known and can be carried out according to conventional methods. For example, natural drying and moist drying can be suitably performed. In addition, drying can be carried out under wind-blocking conditions as needed.

[0088] Drying conditions vary depending on the method used and are not particularly limited. For example, when moist drying is performed under windproof conditions, the ambient temperature can be set to the temperature conditions exemplified in the heat stretching process of this embodiment. Also, for example, processing can be carried out under relative humidity conditions such as 20% to 100%, 30% to 90%, 40% to 90%, 50% to 90%, 60% to 90%, and 60% to 100%. The processing period is not particularly limited, but for example, it can be 1 to 20 days, 5 to 20 days, 10 to 20 days, 10 to 17 days, 10 to 15 days, 10 to 14 days, 12 to 20 days, 12 to 17 days, 12 to 16 days, and 14 to 20 days.

[0089] Examples of coagulants include lower alcohols (methanol, ethanol, propanol, etc.), polyhydric alcohols (glycerin, ethylene glycol, polyethylene glycol, etc.), acetone, dimethyl sulfoxide, tetrahydrofuran, diethyl ether, acetonitrile, N,N-dimethylformamide, N-methyl-2-pyrrolidone, 1,4-dioxane, or solutions containing these. When the coagulant is a solution containing a lower alcohol or acetone, its concentration may be, for example, 10% to 98%, 20% to 97%, 30% to 96%, 40% to 95%, 50% to 90%, 60% to 85%, or 70% to 80% of the lower alcohol in the coagulant.

[0090] The temperature of the coagulant used in this process is not particularly limited, but it can be above the freezing point of the coagulant and below 40°C, above the freezing point of the coagulant and below 30°C, above the freezing point of the coagulant and below 20°C, above the freezing point of the coagulant and below 15°C, above the freezing point of the coagulant and below 10°C, above the freezing point of the coagulant and below 7°C, above the freezing point of the coagulant and below 5°C, -3°C to 10°C, -3°C to 7°C, -3°C to 5°C, 0°C to 10°C, 0°C to 7°C, 0°C to 5°C, etc.

[0091] Additional optional processing may be performed during this process. While there are no specific limitations on the specific processing, examples include dilution, mixing, concentration of the dope solution, addition of chemicals, or combinations thereof.

[0092] For example, the doping solution can be adjusted to a predetermined concentration before coagulation. The concentration of the doping solution used for coagulation is not particularly limited, but for example, it may be 0.1% or more, 0.5% or more, 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 5.5% or more, 6% or more, 6.5% or more, or 7% or more in terms of mass % of polypeptide relative to the mass of the aqueous solution (hereinafter the same applies in this specification). Alternatively, for example, it may be 40% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 9% or less, 8% or less, 7.5% or less, or 7% or less. Specific concentration ranges include, for example, 0.1% to 40%, 0.5% to 40%, 1% to 40%, 3% to 40%, 5% to 40%, 5.5% to 40%, 6% to 40%, 6.5% to 40%, 7% to 40%, 0.1% to 20%, 0.5% to 20%, 1% to 20%, 3% to 20%, 5% to 20%, 5.5% to 20%, 6% to 20%, 6.5% to 20%, 7% to 20%, 0.5% to 10%, 1% to 10%, 3% to 10%, 5% to 10%, 5.5% to 10%, 6% to 10%, 6.5% to 10%, 7% to 10%, etc.

[0093] 1-3-2. Pre-molding process The "pre-molding process" is an optional step of the method according to this embodiment, and is a process of molding the solidified product into a desired shape to produce the molded solidified product. Typically, this process is performed simultaneously with the solidification process.

[0094] This process can be carried out, for example, when the shape of the solidified molded product in this embodiment is fixed.

[0095] The molding method used in this process can be any method known in the manufacturing fields of synthetic resins, chemical fibers, and metal molding, which is used to obtain solids of a desired shape. When obtaining a solidified molded product of a desired shape during solidification from the doping liquid, this process is performed simultaneously with the solidification process. Furthermore, by using, for example, the method exemplified in the molding process of the second embodiment, the solidified molded product obtained in the solidification process can be molded without dissolving it.

[0096] The specific method varies depending on the desired shape and is not particularly limited, but preferably a method that does not involve stretching is used. The specific method also varies depending on the type of desired shape and is not particularly limited, but for example, wet and / or dry molding methods can be suitably used.

[0097] If the desired shape is fibrous, for example, a fiber molding method can be used. Known fiber molding methods include dry fiber molding, wet fiber molding, molten fiber molding, emulsion fiber molding, and gel fiber molding. For example, dry fiber molding or wet fiber molding can be suitably used.

[0098] The "dry fiber forming method" is a method in which a doping liquid is extruded from a die into heated air, and the solvent is evaporated to form fibers.

[0099] The "wet fiber forming method" is a method of forming fibers by extruding a doping solution into a suitable coagulant.

[0100] Methods for forming the film include, for example, solution casting, wet film formation, compression molding, and extrusion molding, as well as methods used for coating.

[0101] The "solution casting method" is a method of forming a film by pouring a doping solution onto a smooth surface, allowing it to adhere to the surface, and then evaporating the solvent by heating or other means. The smooth surface can be the surface of a petri dish, a drum (casting drum), or a smooth stainless steel belt. Furthermore, a mold can be placed on the smooth surface to achieve the desired shape if necessary.

[0102] "Wet film formation" is a method of forming a film by extruding a doping solution into a suitable coagulant.

[0103] "Compression molding" is a molding method in which a dope liquid is poured into a female mold and then compressed and solidified in a male mold.

[0104] The coating method typically involves bringing a coating liquid into contact with the surface of an object. A mold can be used as the object and a doping solution as the coating liquid in this process. Examples of contact methods include nozzle flow, spray, dip, roll, and spin methods.

[0105] In addition to the various methods described above, injection molding and other methods can be used to form the material into a plate shape.

[0106] "Injection molding" is a molding method in which a dope liquid is poured into a mold and allowed to solidify.

[0107] Furthermore, molding may be performed by methods such as 3D printing. The molding method in this case is not particularly limited, but methods such as fused deposition modeling can be used. In addition to these methods, various molding methods described in the molding process of the second embodiment can also be used.

[0108] The shape of the solidified molded product is not particularly limited. For example, any shape commonly used for the resin before stretching is acceptable. For example, it can be rod-shaped, fibrous, flat (film-shaped (including sheet-shaped), plate-shaped, etc.), other granular (convex, polyhedral, spherical, columnar, conical, pellet-shaped or granular, etc.), or a combination thereof.

[0109] The size of the solidified molded product, such as its dimensions or length, and its thickness or maximum diameter, is not particularly limited.

[0110] 1-3-3. Heat stretching process The "heat stretching process" is an essential step of the method of this embodiment, and the solidified molded product derived from a polypeptide solution is stretched with a heat stretching constant V h This is a process of stretching at a temperature of 500°C and a speed of 500 mm / s or higher. If a solidification process is performed, this process can be carried out simultaneously or afterward. Similarly, if a pre-molding process is performed, this process can be carried out simultaneously or afterward. For example, if a solidification process and / or a pre-molding process are performed, this process can be carried out after either of those processes.

[0111] Heat spreading constant V h The temperature T during stretching is s and the stretching speed V during stretchings , and using a predetermined temperature T0, it is defined by the following equation II: V h = (T s -T0) × V s (II) (wherein, T s indicates the temperature during stretching, T0 indicates a predetermined temperature, and V s (This indicates the stretching speed during extension.)

[0112] The predetermined temperature T0 is preferably 145°C. The heat constant in this case is V. h V is defined by the following equation I. h = (T s -145) × V s (I) (where T s V indicates the temperature during stretching. s (This indicates the stretching speed during extension.)

[0113] Heat spreading constant V hThe specific value is not limited, but for example, 500°C / mm / s or higher, 550°C / mm / s or higher, 600°C / mm / s or higher, 700°C / mm / s or higher, 800°C / mm / s or higher, 900°C / mm / s or higher, 1000°C / mm / s or higher, 1100°C / mm / s or higher, 1150°C / mm / s or higher, 1180°C / mm / s or higher, 1182°C / mm / s or higher, 1185°C / mm / s or higher, 1190°C / mm / s or higher, 1200°C / mm / s or higher, 1300°C / mm / s or higher, 1400 ℃・mm / s or more, 1500℃・mm / s or more, 1600℃・mm / s or more, 1700℃・mm / s or more, 1800℃・mm / s or more, 1900℃・mm / s or more, 1950℃・mm / s or more, 1960℃・mm / s or more, 1965℃・m m / s or more, 1970℃・mm / s or more, 2000℃・mm / s or more, 2200℃・mm / s or more, 2400℃・mm / s or more, 2500℃・mm / s or more, 2550℃・mm / s or more, 2560℃・mm / s or more, 2570℃・mm / s 2600℃・mm / s or higher, 2700℃・mm / s or higher, 2720℃・mm / s or higher, 2725℃・mm / s or higher, 2726℃・mm / s or higher, 2730℃・mm / s or higher, 2800℃・mm / s or higher, 3000℃・mm / s or higher, 3200℃・mm / s or more, 3400℃・mm / s or more, 3500℃・mm / s or more, 3550℃・mm / s or more, 3560℃・mm / s or more, 3564℃・mm / s or more, 3565℃・mm / s or more, 3570℃・mm / s or more, 360 The temperature can be 0°C / mm / s or higher, 3700°C / mm / s or higher, 3750°C / mm / s or higher, 3770°C / mm / s or higher, 3775°C / mm / s or higher, 3778°C / mm / s or higher, 3779°C / mm / s or higher, 3780°C / mm / s or higher, 3800°C / mm / s or higher, 4000°C / mm / s or higher, 4500°C / mm / s or higher, 5000°C / mm / s or higher, 5100°C / mm / s or higher, 5200°C / mm / s or higher, 5240°C / mm / s or higher, or 5242°C / mm / s or higher.Also, for example, 18000℃・mm / s or less, 16000℃・mm / s or less, 15000℃・mm / s or less, 13000℃・mm / s or less, 11000℃・mm / s or less, 10000℃・mm / s or less, 9000℃・mm / s or less, 8000℃・mm / s or less, 7000℃・mm / s or less, 6500℃・mm / s or less, 6400℃・mm / s or less, 6000℃・mm / s or less, 5500℃・mm / s or less, 5400℃・mm / s or less, 5300℃・mm / s or less, 5250℃・mm / s or less, 5245℃・mm / s or less, 5244℃・mm / s or less, 5243℃・mm / s or less, 5242℃・m m / s or less, 5240℃・mm / s or less, 5200℃・mm / s or less, 5000℃・mm / s or less, 4500℃・mm / s or less, 4000℃・mm / s or less, 3800℃・mm / s or less, 3790℃・mm / s or less, 3780℃・mm / s or less, 3775℃・mm / s or less, 3770℃・mm / s or less, 3700℃・mm / s or less, 3600℃・mm / s or less, 3570℃・mm / s or less, 356 5℃・mm / s or less, 3564℃・mm / s or less, 3500℃・mm / s or less, 3400℃・mm / s or less, 3300℃・mm / s or less, 3200℃・mm / s or less, 3100℃・mm / s or less, 3 The minimum heat constant should be 000°C / mm / s or less, 2900°C / mm / s or less, 2800°C / mm / s or less, 2750°C / mm / s or less, 2730°C / mm / s or less, 2726°C / mm / s or less, 2725°C / mm / s or less, 2700°C / mm / s or less, 2600°C / mm / s or less, 2580°C / mm / s or less, 2575°C / mm / s or less, 2570°C / mm / s or less, or 2500°C / mm / s or less.

[0114] Specific ranges for the thermal constant include, for example, 500°C / mm / s to 18000°C / mm / s, 550°C / mm / s to 18000°C / mm / s, 600°C / mm / s to 18000°C / mm / s, 800°C / mm / s to 18000°C / mm / s, 1000°C / mm / s to 18000°C / mm / s, 1185°C / mm / s to 18000°C / mm / s, 1950°C / mm / s to 18000°C / mm / s, 1960°C / mm / s to 18000°C / mm / s, and 1965°C / mm / s to 18000°C / mm / s. , 2500℃・mm / s to 18000℃・mm / s, 2550℃・mm / s to 18000℃・mm / s, 2560℃・mm / s to 18000℃・mm / s, 2570℃・mm / s to 18000℃・mm / s, 3550℃・mm / s to 18000℃・mm / s or less, 3560℃・mm / s or more and 18000℃・mm / s or less, 3564℃・mm / s or more and 18000℃・mm / s or less, 3600℃・mm / s or more and 18000℃・mm / s or less, 500℃・mm / s or more and 15000℃・mm / s or less, 550℃・mm / s or more and 1500 0℃・mm / s or less, 600℃・mm / s or more and 15000℃・mm / s or less, 800℃・mm / s or more and 15000℃・mm / s or less, 1000℃・mm / s or more and 15000℃・mm / s or less, 1185℃・mm / s or more and 15000℃・mm / s or less, 1950℃・mm / s or more 15000℃・mm / s or less, 1960℃・mm / s or more and 15000℃・mm / s or less, 1965℃・mm / s or more and 15000℃・mm / s or less, 2500℃・mm / s or more and 15000℃・mm / s or less, 2550℃・mm / s or more and 15000℃・mm / s or less, 2560℃・m m / s or more and 15000℃ / mm / s or less, 2570℃ / mm / s or more and 15000℃ / mm / s or less, 3550℃ / mm / s or more and 15000℃ / mm / s or less, 3560℃ / mm / s or more and 15000℃ / mm / s or less, 3564℃ / mm / s or more and 15000℃ / mm / s or less, 3 600℃・mm / s to 15000℃・mm / s, 500℃・mm / s to 10000℃・mm / s, 550℃・mm / s to 10000℃・mm / s, 600℃・mm / s to 10000℃・mm / s, 800℃・mm / s to 10000℃・mm / s,1000℃・mm / s or higher, 1185℃・mm / s or higher, 1950℃・mm / s or higher, 1960℃・mm / s or higher, 1965℃・mm / s or higher, 2500℃・mm / s or higher, 2550℃・mm / s or higher, 2560℃・mm / s or higher, 2570℃・mm / s or higher, 3550℃・mm / s or higher Above 10000℃・mm / s and below, 3560℃・mm / s and above 10000℃・mm / s and below, 3564℃・mm / s and above 10000℃・mm / s and below, 3600℃・mm / s and above 10000℃・mm / s and below, 500℃・mm / s and above 6400℃・mm / s and below, 550℃・mm / s and above 6400℃・mm / s and below, 600℃・mm / s and above 6400℃・mm / s and below, 800℃・mm / s and above 6400℃・mm / s and below, 1000℃・mm / s and above 6400℃・mm / s and below, 1185℃・mm / s and above 6400℃・mm / s and below, 1950℃・mm / s and below. Temperatures above 6400℃ / mm / s and below, 1960℃ / mm / s and below, 1965℃ / mm / s and below, 2500℃ / mm / s and below, 2550℃ / mm / s and below, 2560℃ / mm / s and below, 2570℃ / mm / s and below, 3550℃ / mm / s and below, 3560℃ / mm / s and below, 3564℃ / mm / s and below, 3 600℃・mm / s or higher, 6400℃・mm / s or lower; 500℃・mm / s or higher, 6000℃・mm / s or lower; 550℃・mm / s or higher, 600℃・mm / s or higher, 6000℃・mm / s or lower; 800℃・mm / s or higher, 6000℃・mm / s or lower; 1000℃・mm / s or higher, 6000℃・mm / s or lower; 1185℃・mm / s or higher, 6000℃・mm / s or lower; 1950℃・mm / s or higher, 6000℃・mm / s or lower; 1960℃・mm / s or higher, 6000℃・mm / s or lower; 1965℃・mm / s or higher, 6000℃・mm / s or lower.2500℃・mm / s or higher than 6000℃・mm / s, 2550℃・mm / s or higher than 6000℃・mm / s, 2560℃・mm / s or higher than 6000℃・mm / s, 2570℃・mm / s or higher than 6000℃・mm / s, 3550℃・mm / s or higher than 6000℃・mm / s, 3560℃・mm / s or higher than 6000℃・mm / s, 3564℃・mm / s or higher than 6000℃・mm / s, 3600℃・mm / s or higher than 6000℃・mm / s, 500℃・mm / s or higher than 5500℃・mm / s, 550℃・mm / s or higher than 5500℃・mm / s 600℃・mm / s or higher, 800℃・mm / s or higher, 1000℃・mm / s or higher, 1185℃・mm / s or higher, 1950℃・mm / s or higher, 1960℃・mm / s or higher, 1965℃・mm / s or higher, 2500℃・mm / s or higher, 2550℃・mm / s or higher, 2560℃・mm / s or higher. 2570℃・mm / s or higher than 5500℃・mm / s, 3550℃・mm / s or higher than 5500℃・mm / s, 3560℃・mm / s or higher than 5500℃・mm / s, 3564℃・mm / s or higher than 5500℃・mm / s, 3600℃・mm / s or higher than 5500℃・mm / s, 500℃・mm / s or higher than 5300℃・mm / s, 550℃・mm / s or higher than 5300℃・mm / s, 600℃・mm / s or higher than 5300℃・mm / s, 800℃・mm / s or higher than 5300℃・mm / s, 1000℃・mm / s or higher than 5300℃・mm / s, 11 85℃・mm / s or higher, 1950℃・mm / s or higher, 1960℃・mm / s or higher, 1965℃・mm / s or higher, 2500℃・mm / s or higher, 2550℃・mm / s or higher, 2560℃・mm / s or higher, 2570℃・mm / s or higher, 3550℃・mm / s or higher, 3560℃・mm / s or higher.The temperature can be set to 3564°C / mm / s or more and 5300°C / mm / s or less, or 3600°C / mm / s or more and 5300°C / mm / s or less, etc.

[0115] The temperature during stretching refers to the temperature of the environment to which the solidified molded product is exposed during stretching. Specifically, for example, if dry stretching is performed in this process, it refers to the temperature of the atmosphere surrounding the solidified molded product; if wet stretching is performed, it refers to the temperature of the liquid in which the solidified molded product is immersed.

[0116] There are no specific temperature limitations, but examples include 150°C or higher, 160°C or higher, 170°C or higher, 180°C or higher, 185°C or higher, 190°C or higher, 191°C or higher, 192°C or higher, 193°C or higher, 194°C or higher, 195°C or higher, 195.4°C or higher, 195.5°C or higher, 196°C or higher, 199°C or higher, 200°C or higher, 205°C or higher, 210°C or higher, 211°C or higher, 212°C or higher, 213°C or higher, 214°C or higher, 214.5°C or higher, and 214.9°C or higher. Furthermore, for example, temperatures below 300°C, 290°C, 270°C, 250°C, 240°C, 230°C, 220°C, 219°C, 218°C, 217°C, 216°C, 215°C, 214°C, 213°C, 210°C, 205°C, 200°C, 199°C, 198°C, 197°C, and 196°C are acceptable.Specific temperature ranges include, for example, 150°C to 300°C, 160°C to 300°C, 170°C to 300°C, 180°C to 300°C, 190°C to 300°C, 195°C to 300°C, 196°C to 300°C, 200°C to 300°C, 205°C to 300°C, 210°C to 300°C, 150°C to 270°C, 160°C to 270°C, 170°C to 270°C, 180°C to 270°C, and 19 0℃ to 270℃, 195℃ to 270℃, 196℃ to 270℃, 200℃ to 270℃, 205℃ to 270℃, 210℃ to 270℃, 150℃ to 250℃, 160℃ to 250℃ Lower, 170℃ to 250℃, 180℃ to 250℃, 190℃ to 250℃, 195℃ to 250℃, 196℃ to 250℃, 200℃ to 250℃, 205℃ to 250℃, 210℃ to 25 0℃ or less, 150℃ or more and 230℃ or less, 160℃ or more and 230℃ or less, 170℃ or more and 230℃ or less, 180℃ or more and 230℃ or less, 190℃ or more and 230℃ or less, 195℃ or more and 230℃ or less, 196℃ or more and 230℃ or less, 200℃ Above 230℃, above 205℃ below 230℃, above 210℃ below 230℃, above 150℃ below 220℃, above 160℃ below 220℃, above 170℃ below 220℃, above 180℃ below 220℃, above 190℃ below 220℃, 1 Examples include temperatures between 95°C and 220°C, 196°C and 220°C, 200°C and 220°C, 205°C and 220°C, 210°C and 220°C, 150°C and 215°C, 160°C and 215°C, 170°C and 215°C, 180°C and 215°C, 190°C and 215°C, 195°C and 215°C, 196°C and 215°C, 200°C and 215°C, 205°C and 215°C, and 210°C and 215°C.

[0117] As described in the definition section, the stretching speed during stretching refers to the difference between the feed speed and the tension speed during stretching, typically the difference between the feed speed and the winding speed during stretching. There are no specific limits on the stretching speed, but examples include 10 mm / s or more, 15 mm / s or more, 20 mm / s or more, 25 mm / s or more, 30 mm / s or more, 35 mm / s or more, 36 mm / s or more, 37 mm / s or more, 38 mm / s or more, 39 mm / s or more, 40 mm / s or more, 45 mm / s or more, 50 mm / s or more, 51 mm / s or more, 52 mm / s or more, 53 mm / s or more, 55 mm / s or more, 60 mm / s or more, 65 mm / s or more, 70 mm / s or more, 71 mm / s or more, 72 mm / s or more, 73 mm / s or more, 74 mm / s or more, and 75 mm / s or more. Furthermore, for example, any stretching speed of 200 mm / s or less, 150 mm / s or less, 125 mm / s or less, 120 mm / s or less, 110 mm / s or less, 100 mm / s or less, 90 mm / s or less, 80 mm / s or less, 79 mm / s or less, 78 mm / s or less, 77 mm / s or less, 76 mm / s or less, 75 mm / s or less, 70 mm / s or less, 60 mm / s or less, 55 mm / s or less, 54 mm / s or less, 53 mm / s or less, or 52 mm / s or less is acceptable. Specific stretching speed ranges include, for example, 10 mm / s to 200 mm / s, 20 mm / s to 200 mm / s, 30 mm / s to 200 mm / s, 35 mm / s to 200 mm / s, 40 mm / s to 200 mm / s, 50 mm / s to 200 mm / s, 55 mm / s to 200 mm / s, 60 mm / s to 200 mm / s, 70 mm / s to 200 mm / s, 75 mm / s to 200 mm / s, 10 mm / s to 150 mm / s, and 20 mm / s to 150 mm / s. , 30mm / s to 150mm / s, 35mm / s to 150mm / s, 40mm / s to 150mm / s, 50mm / s to 150mm / s, 55mm / s to 150mm / s, 60mm / s to 150mm / s, 70mm / s and above 150mm / s or less, 75mm / s or more and 150mm / s or less, 10mm / s or more and 120mm / s or less, 20mm / s or more and 120mm / s or less, 30mm / s or more and 120mm / s or less, 35mm / s or more and 120mm / s or less, 40mm / s or more and 120mm / s or less,50mm / s to 120mm / s, 55mm / s to 120mm / s, 60mm / s to 120mm / s, 70mm / s to 120mm / s, 75mm / s s to 120mm / s, 10mm / s to 100mm / s, 20mm / s to 100mm / s, 30mm / s to 100mm / s, 35mm / s to 10 0mm / s or less, 40mm / s or more and 100mm / s or less, 50mm / s or more and 100mm / s or less, 55mm / s or more and 100mm / s or less, 60mm / s or more and 100mm / s Below, 70mm / s to 100mm / s, 75mm / s to 100mm / s, 10mm / s to 90mm / s, 20mm / s to 90mm / s, 30mm Examples include 1 / s to 90 mm / s, 35 mm / s to 90 mm / s, 40 mm / s to 90 mm / s, 50 mm / s to 90 mm / s, 55 mm / s to 90 mm / s, 60 mm / s to 90 mm / s, 70 mm / s to 90 mm / s, 75 mm / s to 90 mm / s, 10 mm / s to 80 mm / s, 20 mm / s to 80 mm / s, 30 mm / s to 80 mm / s, 35 mm / s to 80 mm / s, 40 mm / s to 80 mm / s, 50 mm / s to 80 mm / s, 55 mm / s to 80 mm / s, 60 mm / s to 80 mm / s, 70 mm / s to 80 mm / s, 75 mm / s to 80 mm / s, etc.

[0118] The stretching method in this process may be either dry stretching or wet stretching, but wet stretching is preferred.

[0119] In the case of wet stretching, the type of liquid used to immerse the solidified molded product is not particularly limited. For example, wet stretching can be performed in an oil bath or a water bath. In the case of an oil bath, the type of oil used is not particularly limited, as long as it is a non-volatile oil that is liquid at the stretching temperature. For example, non-volatile oils commonly used in the art can be used. Specific examples of oils include mineral oils, animal and vegetable oils, synthetic lubricants (fatty acid esters, polyethers, silicone oils, etc.), and other oils commonly used as lubricants or mixtures thereof. In the case of a water bath, the solvent is water or an aqueous solution. When using an aqueous solution, the solute is not particularly limited. For example, solutes commonly used in the art can be used.

[0120] When this process is performed simultaneously with the solidification process, typically the same liquid is used in both processes.

[0121] The stretching method in this process can be appropriately selected depending on the shape of the target insolubilized molded product, and is not particularly limited. For example, if the insolubilized molded product is in the form of a film, either uniaxial stretching or biaxial stretching may be used, and in the case of biaxial stretching, it may be sequential biaxial stretching or simultaneous biaxial stretching. Furthermore, if necessary, multi-stage stretching can be performed in this process.

[0122] The feeding and stretching (winding, etc.) of the solidified molded product may be performed in reverse rotation. In the case of reverse rotation, stretching in this process is performed by pulling both sides of the solidified molded product in opposite directions. In this case, the stretching speed is calculated as described in the definition section by treating one of the stretches as a negative speed feeding.

[0123] Other conditions are not particularly limited. For example, the stretching ratio can be set to any value based on the stretching conditions described above. Specifically, it can be, for example, 2 times or more, 2.5 times or more, 3 times or more, 3.5 times or more, 4 times or more, 4.5 times or more, 5 times or more, etc. Also, for example, it can be 10 times or less, 9 times or less, 8 times or less, 7 times or less, 6 times or less, 5 times or less, etc. A specific range for the stretching ratio can be, for example, 2 times or more and 10 times or less, 3 times or more and 8 times or less, 3 times or more and 7 times or less, 3 times or more and 6 times or less, 3 times or more and 5 times or less, etc.

[0124] Heating and stretching can be performed one or more times additionally. This process may be performed multiple times, and heating and / or stretching may be performed under other conditions. Heating and / or stretching under other conditions can be performed, for example, before and / or after this process. When heating and / or stretching is performed multiple times, the conditions for each process may be the same, or they may differ in one or more heating and / or stretching processes.

[0125] The shape of the insolubilized molded product obtained as a result of this process is not particularly limited, but it can be, for example, a stretched yarn or a stretched film.

[0126] 2. Method for Manufacturing Immobilized Molded Articles 2-1. Overview The second aspect of the present invention is a method for manufacturing polypeptide immobilized molded articles. The method of this aspect includes a heat stretching step as an essential step. According to the method of this aspect, the fibroin molded article described in the third aspect can be manufactured.

[0127] 2-2. Process The method of this embodiment includes a heat stretching step as an essential step, and includes a polypeptide synthesis step, a purification step, a dissolution step, a solidification step, a pre-molding step, and a molding step as optional steps. Each step will be described below.

[0128] 2-2-1. Polypeptide Synthesis Step This step is an optional step of the method according to this embodiment, and is a step of synthesizing a polypeptide that will be used as a raw material for a polypeptide-insolubilized molded article.

[0129] In this process, any polypeptide synthesis method known in the art can be used, and the specific method is not particularly limited. For example, as described in the first embodiment, a silkworm or spider or other silkworm capable of synthesizing fibrous proteins such as fibroin protein, or a microorganism, can be used to synthesize crude fibrous protein (e.g., crude fibroin protein).

[0130] In particular, when using silkworms, the silkworms used may be natural organisms or organisms that have undergone genetic modification or other processing. When using silkworms, crude fibrous protein may be recovered by collecting the silk spun or secreted from the organism, or it may be recovered directly from the lumen of the silk gland.

[0131] When microorganisms are used, genetically modified microorganisms are typically used, and the crude fibrous protein is recovered from the culture medium in which the microorganisms grow and / or from within the microbial cells.

[0132] 2-2-2. Purification Step This step is an optional step of the method according to this embodiment, and is a step of purifying the polypeptide that will be used as a raw material for polypeptide-insolubilized molded articles from the synthesized crude polypeptide. This step can be performed simultaneously with or after the polypeptide synthesis step.

[0133] This process can be carried out, for example, when the crude polypeptide contains a large amount of impurities.

[0134] In this process, any polypeptide purification method known in the art can be used, and the specific method is not particularly limited. If crude fibroin protein is recovered as silk yarn in the polypeptide synthesis process, it can be purified, for example, by using a method commonly used for scouring silk yarn.

[0135] Furthermore, for example, if crude polypeptide is recovered from the lumen of a silk gland or from microorganisms, chromatographic methods such as gel filtration chromatography, ion exchange column chromatography, affinity chromatography, reversed-phase column chromatography, hydrophobic chromatography, chromatographic focusing, and HPLC, as well as electrophoretic methods such as ammonium sulfate fractionation, ultrafiltration, immunoadsorption, solvent extraction, desalting, precipitation with organic solvents, isoelectric focusing, or combinations thereof can be used.

[0136] 2-2-3. Dissolution Step This step is an optional step of the method according to this embodiment, and is a step of dissolving the polypeptide in a solvent to prepare a dope solution. When the polypeptide synthesis step is performed, this step can be performed simultaneously with or after it.

[0137] This process can be carried out, for example, when a polypeptide insoluble in water is used. Such polypeptides also include solidified molded articles.

[0138] If the crude polypeptide does not contain many impurities or if a polypeptide of sufficient purity is available, the crude polypeptide can be used directly in this process. Furthermore, if the impurities in the crude polypeptide are insoluble in the solvent used in this process, and are removed by this process, the purification process can be performed simultaneously with this process. Alternatively, for example, the purification process may be performed after preparing the dope solution in this process.

[0139] The solvent for the doping solution can be any solvent commonly used in the art, and is not particularly limited. For example, polar or nonpolar organic solvents, aqueous solvents such as water or aqueous solutions, or combinations thereof, preferably polar solvents, can be used.

[0140] Specific examples of polar organic solvents include dimethyl sulfoxide, N-methylmorpholine N-oxide (NMMO), N-methylmorpholine (NMM), 1-butyl-3-methylimidazolium chloride (BMIMCl), 1,5-diazabicyclo[4.3.0]non-5-enium acetate, dioxane, hydrazine, N,N-dimethylformamide, N,N-dimethylacetamide, 1,1,1,3,3,3-hexafluoro-2-propanol, methanol, ethanol, propanol, formic acid, or combinations thereof.

[0141] Furthermore, the doping solution may contain inorganic salts, and the specific types are not particularly limited. Examples include halides (such as sodium iodide), nitrates, perchlorates, cyanates, thiocyanates, urea, guanidine salts (such as guanidine hydrochloride, guanidine sulfate, guanidine thiocyanate, etc.), or combinations thereof, that contain metal ions such as alkali metal ions or alkaline earth metal ions, or ammonium ions as cations. Specific examples of nitrates include lithium nitrate, strontium nitrate, nickel nitrate, calcium nitrate, cobalt nitrate, zinc nitrate, magnesium nitrate, ferrous nitrate, manganese nitrate, chromium nitrate, ferric nitrate, and aluminum nitrate. Specific examples of thiocyanates include potassium thiocyanate, sodium thiocyanate, lead thiocyanate, copper thiocyanate, lithium thiocyanate, barium thiocyanate, strontium thiocyanate, nickel thiocyanate, calcium thiocyanate, cobalt thiocyanate, zinc thiocyanate, magnesium thiocyanate, ferrous thiocyanate, manganese thiocyanate, chromium thiocyanate, ferric thiocyanate, and aluminum thiocyanate. When using an aqueous solvent, an aqueous solution containing these inorganic salts as a solute (such as an aqueous solution of thiocyanate) can be used.

[0142] The concentration of the inorganic salt is not particularly limited. For example, it may be a saturated solution or an unsaturated solution.

[0143] Other dissolution conditions such as temperature and time vary depending on the solvent and inorganic salt used, and are not particularly limited. Examples of temperatures include freezing temperatures (below 0°C), refrigeration temperatures (0°C to 10°C), low temperatures (10°C to 20°C), cool places (1°C to 15°C), room temperature (15°C to 25°C), ambient temperature (1°C to 30°C), lukewarm temperatures (30°C to 40°C), 40°C to 100°C, 60°C to 100°C, 80°C to 100°C, 40°C to 80°C, and 60°C to 80°C. Examples of times include 1 minute or more, 5 minutes or more, 10 minutes or more, 30 minutes or more, 50 minutes or more, 60 minutes or more, 2 hours or more, 6 hours or more, 12 hours or more, 18 hours or more, 24 hours or more, 2 days or more, 5 days or more, and 1 week or more.

[0144] 2-2-4. Solidification Process This process is an optional step of the method in this embodiment and is a process for preparing a solidified molded product from the dope liquid. If a dissolution process is performed, this process can be performed simultaneously with or after it. The specific details of this process are the same as those described for the solidification process in the first embodiment.

[0145] 2-2-5. Pre-molding process The "pre-molding process" is an optional step of the method according to this embodiment, and is a process of molding the solidified product into a desired shape to produce the molded solidified product. Typically, this process is performed simultaneously with the solidification process.

[0146] This process can be carried out, for example, when it is required to change the shape of the solidified molded product, which is the raw material for this embodiment. The specific details of this process are the same as those described in the pre-molding process in the first embodiment.

[0147] 2-2-6. Heat stretching process The "heat stretching process" is an essential step of the method of this embodiment, and the solidified molded product derived from a polypeptide-containing solution (doping solution) is stretched with a heat stretching constant V h This is a process of stretching at a temperature of 500°C and a speed of 500 mm / s or higher. If a solidification process is performed, this process can be carried out simultaneously with or after it. If a pre-molding process is performed, this process can be carried out simultaneously with or after it. For example, if a solidification process and / or a pre-molding process are performed, this process can be carried out after either process. This process may be carried out in accordance with the description in the first embodiment.

[0148] 2-2-7. Molding Process The "molding process" is an optional step of the method according to this embodiment, and is a process of molding the insolubilized molded product into a desired shape to produce a polypeptide insolubilized molded product. This process can be performed simultaneously with or after the heat stretching process.

[0149] The method used in this process is widely known in fields such as the manufacturing of synthetic resins and chemical fibers, and can be appropriately selected according to the type of molded product to be manufactured. The type of molded product is not particularly limited, but examples include the shapes exemplified for solidified molded products in the first embodiment. Furthermore, this process can be appropriately selected according to the type of final product. The type of final product is not particularly limited, but examples include the products exemplified in the third embodiment.

[0150] If the desired shape is obtained as a result of stretching a solidified molded product, this process is performed simultaneously with the heat stretching process through a stretching treatment.

[0151] When this process is performed separately from the stretching process, it is preferable that the molding is carried out without dissolving the insolubilized molded product.

[0152] Any known molding method from the fields of resin processing or metal processing can be used. Examples include, but are not limited to, vacuum forming, bonding / welding, lamination, cutting, punching, bending, or combinations thereof.

[0153] "Vacuum forming" is a method of forming a softened, sheet-like, insoluble molded product into the shape of the mold by bringing it into contact with a mold and then reducing the pressure in the gap between the mold and the solidified product.

[0154] "Adhesion and welding" refers to a molding method in which multiple insolubilized molded products are joined together using an adhesive or by softening the bonding area.

[0155] "Lamination molding" is a method of forming products by laminating insolubilized molded products in sheet form or other shapes and then softening them by applying pressure, heating, etc.

[0156] "Cutting" refers to a method of shaping insolubilized molded products by cutting and removing material. This includes methods such as water jet machining.

[0157] "Die-cutting" is a molding method that involves pressing a die against an insolubilized molded product.

[0158] "Bending" is a molding process that involves softening an insolubilized molded product by applying pressure or heating, then bending it, and finally solidifying it.

[0159] 2-3. Effects According to the method of this embodiment, an immobilized molded article with a low swelling shrinkage rate and low shrinkage due to wetting can be produced without the need for additional processing after stretching. An immobilized molded article produced by the method of this embodiment (for example, provided by a molding process) has a predetermined swelling shrinkage rate, for example, as described for a fibroin immobilized molded article in the third embodiment.

[0160] 3. Immobilized Molded Articles 3-1. Overview The third aspect of the present invention is an immobilized molded article. The immobilized molded article of the present invention is characterized by a low swelling shrinkage rate.

[0161] 3-2. Structure The structure of the insolubilized molded articles of the present invention will be described below. The insolubilized molded articles of the present invention are broadly classified into polypeptide insolubilized molded articles and fibroin insolubilized molded articles. Each structure will be described in detail below.

[0162] (1) Polypeptide-insolubilized molded article The polypeptide-insolubilized molded article in this embodiment is an insolubilized molded article produced by the manufacturing method described in the second embodiment.

[0163] The shape of the immobilized molded product in this embodiment is not particularly limited. For example, it can be the shape exemplified in the pre-molding step in the first embodiment. The polypeptide immobilized molded product can be provided as, for example, a thin film molded product, a fine particle molded product, or a fiber molded product.

[0164] Depending on the purpose and application, additives may be added as appropriate. In that case, the additives are preferably used in a range that does not impair the low swelling and shrinkage rate exhibited by the insolubilized molded product in this embodiment.

[0165] The applications of the immobilized molded product in this embodiment are not particularly limited. The immobilized molded product in this embodiment exhibits a low swelling and shrinkage rate, and its dimensions do not change easily even when wet. Therefore, it can be used, for example, in applications where it may get wet and where it is preferable for its dimensions to remain constant, such as base materials such as FRP materials, reinforcing materials such as FRP materials, outdoor products, clothing, food packaging, waterproof films, building films (glass films, etc.), wrapping films for cars and flowers, sutures, medical sheets (bandages, regenerative medicine base materials, etc.), protective films, etc.

[0166] The swelling and shrinkage rate exhibited by polypeptide-insolubilized molded articles is, for example, within the range described later for fibroin-insolubilized molded articles.

[0167] (2) Fibroin-insolubilized molded product: This is an insolubilized molded product made from a fibroin protein solution and exhibiting a predetermined swelling and shrinking rate.

[0168] The origin of the fibroin protein used here is not particularly limited, but for example, fibroin protein derived from silkworms or spiders, especially silkworms such as bagworms, can be suitably used.

[0169] "Specified swelling and shrinkage rate" refers to a swelling and shrinkage rate of less than 20%. Specifically, the swelling and shrinkage rate should be, for example, 19% or less, 18% or less, 17% or less, 16.5% or less, 16.3% or less, 16.2% or less, 16% or less, 15.5% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10.5% or less, 10% or less, 9.5% or less, 9% or less, 8.9% or less, 8.8% or less, 8.7% or less, 8.5% or less, 8% or less, 7% or less, 6% or less, 5.5% or less, 5.4% or less, 5.3% or less, etc.

[0170] For example, the swelling-shrinkage rate is measured by immersing a 150 mm long test specimen, marked at two points with a distance of 100 mm between them, in ultrapure water (approximately 25-27°C) for 5 minutes. The difference in distance between the marks before and after immersion (ΔL) is then divided by the distance between the marks before immersion (100 mm), and the result is expressed as a percentage of this value. Therefore, it is sufficient if the measured value falls within the range mentioned above.

[0171] If the immobilized molded product is a flat shape such as a film, woven fabric, or knitted fabric, the dimensional change rate may be used instead of the swelling shrinkage rate. The measurement method in this case is not particularly limited, but for example, it can be measured by Method A (room temperature water immersion method) of JIS L 1096. In this case, for example, even if the dimensional change rate of a woven or knitted fabric is not within the above range, if the swelling shrinkage rate of the raw material yarn falls within the above range, the raw material yarn is included in the immobilized molded product of the present invention.

[0172] The shape, additives, and uses shall be in accordance with the description for polypeptide-insolubilized molded products.

[0173] <Example 1. Relationship between stretching conditions and wettability> (Objective) To investigate the effect of stretching conditions on wettability.

[0174] (Method) 1. Preparation of the dope solution As the raw material fibroin protein, a protein having the amino acid sequence of Sequence ID No. 24, which is a mutant bagworm FibH, was used. This protein is a protein in which the C-terminus of a mutant FibH gene newly constructed in WO2020 / 235692 has been deleted, based on the base information of the giant bagworm FibH gene identified in Japanese Patent No. 6990413.

[0175] An expression vector designed by inserting a nucleic acid fragment containing the base sequence encoding this protein into a pET26b(+) vector (Novagen) was introduced into E. coli BLR(DE3) strain (Novagen). The gene-modified E. coli was inoculated into LB medium and OD 600 The cells were incubated at 37°C until the concentration reached 0.7. After incubation, isopropyl-β-thiogalactopyranoside (IPTG: Fujifilm Wako Pure Chemical Industries, Ltd.) was added to a final concentration of 1 mM to induce protein expression, and induction culture was carried out at 20°C for 22 hours.

[0176] After induction culture, the bacterial cells were recovered as a precipitate by centrifugation. The recovered bacterial cells were mixed with lithium solution, and the soluble fraction was separated and purified to purify the mutant bagworm FibH. The specific method was carried out according to the description in Japanese Patent Application Publication No. 2022-145193.

[0177] 2. Preparation of Undrawn Yarn: Undrawn yarn was obtained using a wet fiber molding apparatus with a 7% aqueous solution of the mutant bagworm FibH as the doping solution. The wet fiber molding apparatus consisted of a 1 mL Terumo syringe (Terumo Corporation, SS-01T) filled with the doping solution and a Terumon bevel needle 22G x 1 1 / 2 A device (Terumo Corporation, NN-2238N) was used, with the needle tip placed in a coagulant (60% ethanol aqueous solution, 5°C). The doping solution was delivered from the syringe by pushing the plunger using a Legato 101 (KDS Corporation) to achieve a delivery rate of 4 μL / min, and the thread was wound using a winding device set to a rotation speed of 4 mm / s.

[0178] 3. The undrawn yarn obtained after stretching was stretched using an oil bath stretching apparatus set to the conditions shown in Table 1 below. The stretching ratio was 4 times under all conditions.

[0179]

[0180] The heat-sustaining constant Vh (°C・mm / s) was calculated using the following formula I. h = (T s -145) × V s (I)

[0181] 4. Wetting Shrinkage Test: The drawn yarn obtained under each drawing condition was cut into 150 mm lengths, and two marks were made on the drawn yarn with tape so that the distance between the marks was 100 mm (L0). The entire drawn yarn was immersed in ultrapure water (approximately 25-27°C) for 5 minutes, then the yarn was removed from the water bath and dried for 5 minutes. The distance between the marks after drying (L0) d The following measurements were taken, and the swelling-shrinkage rate (%) was calculated based on the following formula: Swelling-shrinkage rate (%) = (L0 - L0) d ) / L0 × 100

[0182] The immersion time and drying time were determined based on preliminary experiments that confirmed the yarn's shrinkage had reached a sufficient equilibrium.

[0183] (Results) The results are shown in Figures 1 and 2. Figure 1 shows the stretching temperature T s (°C) and stretching speed V s This figure shows the relationship between (mm / s) and swelling shrinkage rate (%). Figure 2 shows the relationship between the stretching temperature Ts (°C) and stretching speed V s The thermal constant V calculated from (mm / s) h This figure shows the results of plotting the same data as in Figure 1 for (°C・mm / s) and swelling / shrinkage rate (%). The values ​​in each circle in Figure 1 correspond to the values ​​on the vertical axis of each point in Figure 2.

[0184] As shown in Figure 1, the lower the stretching speed (horizontal axis) and the lower the temperature (vertical axis), the greater the swelling shrinkage rate (size of the circle), resulting in a yarn that is less resistant to wetting. Conversely, as the stretching speed and temperature increase, the swelling shrinkage rate decreases, suggesting that a fiber that is more resistant to wetting can be obtained.

[0185] Furthermore, as shown in Figure 2, the constant of heat of extension V h The temperature (°C・mm / s) and swelling / shrinkage rate (%) show a strong correlation, and the heat constant V h It was suggested that the higher the temperature (°C・mm / s) under which the stretching is performed, the more wett-resistant the resulting fiber will be. All publications, patents, and patent applications cited herein are incorporated herein by direct reference.

Claims

1. A method for producing a polypeptide-insolubilized molded article, wherein the solidified molded article derived from a polypeptide solution is given a heat-adjusting constant V shown in formula I. h The manufacturing method comprising a heat stretching step in which the material is stretched under conditions of 500°C・mm / s or higher. [Equation 1] V h = (T s -145) × V s (I) (where T s V indicates the temperature during stretching. s (This indicates the stretching speed during extension.) 2. The aforementioned heat extension constant V h The manufacturing method according to claim 1, wherein the temperature is 600°C・mm / s or more and 18000°C・mm / s or less.

3. Temperature T during stretching s The manufacturing method according to claim 1 or 2, wherein the temperature is 150°C or higher and 250°C or lower.

4. The stretching speed V during said stretching s is 30 mm / s or more and 150 mm / s or less, the production method according to claim 1 or 2.

5. The manufacturing method according to any one of claims 1 to 4, wherein the stretching ratio in the heat stretching step is 3 times or more and 7 times or less.

6. The manufacturing method according to any one of claims 1 to 5, wherein the stretching is wet stretching.

7. The manufacturing method according to any one of claims 1 to 6, further comprising a solidification step of solidifying a polypeptide-containing solution by desolvent treatment before the heat stretching step to produce a solidified molded product.

8. The method for producing a polypeptide according to any one of claims 1 to 7, wherein the polypeptide comprises a fibroin protein.

9. The manufacturing method according to claim 8, wherein the fibroin protein is derived from bagworm silk.

10. The manufacturing method according to any one of claims 1 to 9, wherein the polypeptide-insolubilized molded product is a drawn yarn.

11. A fibroin-insolubilized molded product made from a fibroin protein solution, having a swelling-shrinkage rate of 19% or less.

12. A polypeptide-insolubilized molded article produced by the manufacturing method described in any one of claims 1 to 10.

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