Abstract: Provided is a side-by-side type composite fiber having a latent crimping ability, including a first component containing a modified fibroin and a second component containing a structural protein, in which the first component and the second component are joined to each other.

Abstract: Provided is a molded article of a composition comprising a polypeptide, wherein the polypeptide is at least one kind selected from the group consisting of natural spider silk protein and polypeptides derived from natural spider silk protein.

Abstract: The present invention relates to a method for manufacturing a protein fiber, the method including a step of bringing a spinning raw liquid containing a spider silk protein and a solvent into contact with a coagulation liquid to coagulate the spider silk protein, in which the coagulation liquid contains a ketone.

Abstract: An object of the present invention is to provide a method for efficiently manufacturing a protein crimped staple from protein filaments at a low cost. A manufacturing method for a protein crimped staple according to the present invention includes: a) preparing an artificial fibroin filament containing a modified fibroin; b) cutting the artificial fibroin filament to obtain an artificial fibroin staple; and c) performing crimping by bringing the artificial fibroin filament into contact with an aqueous medium to crimp the artificial fibroin filament before the cutting or bringing the artificial fibroin staple into contact with an aqueous medium to crimp the artificial fibroin staple after the cutting.

Abstract: The present invention aims at providing a blended yarn with which a knitted or woven body, wherein a decrease in tension and stiffness due to moistness is reduced, can be manufactured, even in a case where the blended yarn is used for the manufacture of the knitted or woven body; a knitted or woven body of the same; and a method for manufacturing the knitted or woven body. The blended yarn according to the present invention comprises a modified fibroin fiber and a regenerated cellulose fiber.

Abstract: The present invention relates to a production method for a protein molded article, including: dissolving a protein in a solvent containing formic acid at a temperature of 40° C. or higher and lower than 80° C. to obtain a protein solution; and molding a protein molded article using the protein solution.

Abstract: An object of the present invention is to provide a method for efficiently separating insoluble bodies of a recombinant protein from a recombinant cell expressing a target recombinant protein as insoluble bodies in the cell. The present invention provides a method for producing a recombinant protein aggregate by separating insoluble bodies of a recombinant protein from a recombinant cell expressing the recombinant protein as insoluble bodies in the cell, including disrupting the recombinant cell, aggregating the insoluble bodies of the recombinant protein, and separating the resulting aggregate.

Abstract: A method for producing a fibroin-like protein is described. A fibroin-like protein is produced by culturing Escherichia coli having a gene encoding the fibroin-like protein in a medium, inducing expression of the gene encoding the fibroin-like protein, and collecting the fibroin-like protein, wherein the cell proliferation after inducing the expression is reduced.

Abstract: Disclosed is an expression cassette comprising, in a 5? to 3? direction of a sense strand, a promoter, and a first nucleic acid, a terminator and a second nucleic acid operably linked to the promoter, wherein the first nucleic acid and the second nucleic acid each contain at least one gene.

Abstract: A method for producing a fibroin-like protein is described. A fibroin-like protein is produced by culturing Escherichia coli having a gene encoding the fibroin-like protein in a medium, inducing expression of the gene encoding the fibroin-like protein, and collecting the fibroin-like protein, wherein the cell proliferation after inducing the expression is reduced.

Abstract: The present invention relates to a method for producing a double-stranded DNA fragment having a desired nucleotide sequence through dual asymmetric PCR (DA-PCR). The method comprises: (1) providing a plurality of oligonucleotides (sense oligonucleotides) each corresponding to a part of a sense strand of the double-stranded DNA fragment and a plurality of oligonucleotides (antisense oligonucleotides) each corresponding to a part of an antisense strand of the double-stranded DNA fragment and mixing together the oligonucleotides with equal concentrations, DNA polymerase, and dNTP to prepare a reaction mixture solution; (2) performing PCR by using the reaction mixture solution from step (1); (3) adding a primer set capable of amplifying the double-stranded DNA fragment of full length to the reaction mixture solution from step (2); and (4) performing PCR by using the reaction mixture solution from step (3).

Abstract: The present invention relates to a modified fibroin including a domain sequence represented by Formula 1: [(A)n motif-REP]m or Formula 2: [(A)n motif-REP]m-(A)n motif, in which the domain sequence has an amino acid sequence with a reduced content of a glutamine residue equivalent to an amino acid in which one or a plurality of glutamine residues in REP are deleted or substituted with other amino acid residues, as compared with a naturally occurring fibroin. [In Formula 1 and Formula 2, (A)n motif represents an amino acid sequence consisting of 4 to 27 amino acid residues, and the number of alanine residues with respect to the total number of amino acid residues in the (A)n motif is 80% or more. REP represents an amino acid sequence consisting of 10 to 200 amino acid residues. m represents an integer of 10 to 300. A plurality of (A)n motifs may be the same amino acid sequence or different amino acid sequences.

Abstract: The present invention relates to a polypeptide solution in which polypeptide including an amino acid sequence derived from type I keratin that belongs to Cluster Ia is dissolved in a solvent including a formic acid or a solvent including an aprotic polar agent having a dipole moment of 3.0 D or more and an inorganic salt.

Abstract: A composite material 100 is obtained by laminating and tightly adhering a fabric 60 containing fibers made of spider silk fibroin and a synthetic resin film 50 having a tensile elongation equal to or greater than that of the fabric 60.

Abstract: The present invention relates to a protein molded article including a protein, in which an ionic liquid is included inside the protein molded article. The present invention also relates to a production method of the protein molded article, including a step of adding the ionic liquid to a molding material of the protein molded article. Further, the present invention relates to a protein solution including a protein, an ionic liquid, and a solvent. Further, the present invention also relates to a protein molded article plasticizer including an ionic liquid.

Abstract: The present invention relates to a method for manufacturing a protein fiber, including an extension and contraction step of contracting or extending a protein raw fiber containing a protein by bringing the protein raw fiber into contact with a liquid or vapor; and a drying step of drying the protein raw fiber that has undergone the extension and contraction step while adjusting a length of the protein raw fiber to an arbitrary length.

Abstract: The present invention relates to a highly contracted artificial fibroin fiber including a modified fibroin, in which a contraction percentage defined by the following equation exceeds 7%.

Abstract: One aspect of the present invention is a microbial growth inhibitor comprising xanthurenic acid.

Abstract: The present invention relates to a method for recovering protein, which recovers a target protein from a mixture containing the target protein and a material different from the target protein, the method including a dissolution step of dissolving either the target protein or the material by applying pressure while heating to a solution for dissolution containing the mixture and a polar solvent, and a separation step of separating an obtained solution.

Abstract: The present invention relates to a protein composition formed of dry matter of a dispersion in which a protein is dispersed in a stabilizer solution, in which the stabilizer includes at least one type selected from the group consisting of a catechol-based stabilizer, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-4-methoxyphenol, and 6,6?-di-tert-butyl-4,4?-butylidenedi-m-cresol.