Spiber Inc.

Riken Corporation

Keisuke Morita

Toshiaki Osawa

Yunosuke Abe

Junichi Sugahara

Hiroyuki Nakamura

Keiji Numata

Tetsuo Asakura

Ayumi Abe

Takehisa Maekawa

Shota Togashi

Koichi Kotaka

Yuya Sato

Kenji Kurachi

The present invention relates to a modified fibroin including a domain sequence represented by Formula 1: [(A)motif-REP]or Formula 2: [(A)motif-REP]-(A)motif, and having a serine residue content rate of less than 5.5%. [In Formula 1 and Formula 2, the (A)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)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. The plurality of (A)motifs may be the same amino acid sequence or different amino acid sequences. A plurality of REPs may be the same amino acid sequence or different amino acid sequences.]

Modified fibroin

The present invention relates to a polypeptide solution in which a 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.

Polypeptide solution, production method for polypeptide fiber, and artificial polypeptide

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%.Contraction percentage={1−(length of contracted artificial fibroin fiber/length of artificial fibroin fiber before being brought into contact with water after spinning)}×100(%)

Highly contracted synthetic fibroin fiber, production method therefor, and method for contracting synthetic fibroin fiber

The present invention relates to a modified fibroin including a domain sequence represented by Formula 1: [(A)motif-REP]or Formula 2: [(A)motif-REP]&#x2212;(A)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.

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.

Production method for insoluble recombinant protein aggregate

A polypeptide porous body of the present invention is a porous body of a polypeptide derived from spider silk proteins. The polypeptide includes a water-insoluble polypeptide. The polypeptide porous body has an apparent density of 0.1 g/cmor less. A method for producing the polypeptide porous body includes: a solution production step in which the polypeptide is dissolved in at least one solvent selected from DMSO, DMF, and these with an inorganic salt, so as to obtain a solution of the polypeptide; a step in which the solution produced in the solution production step is substituted with a water-soluble solvent so as to obtain a polypeptide gel; and a step in which the polypeptide gel is dried. Thereby, the present invention provides a polypeptide porous body having excellent water absorbability and a polypeptide porous body suitable for application to a living body, and a method for producing the same.

Polypeptide porous body and method for producing same

A polypeptide hydrogel of the present invention is a hydrogel of a polypeptide derived from spider silk proteins, and has a moisture content of 85.0 to 99.9 mass % based on 100 mass % of the polypeptide hydrogel. A method for producing the hydrogel includes: a solution production step in which a polypeptide derived from spider silk proteins is dissolved in at least one dissolving solvent selected from the group consisting of: (A) dimethyl sulfoxide; (B) dimethyl sulfoxide with an inorganic salt; and (C) N, N-dimethylformamide with an inorganic salt, so as to obtain a solution of the polypeptide; and a substitution step in which the solution produced in the solution production step is substituted with a water-soluble solvent. Thus, the present invention provides a polypeptide hydrogel having excellent water retentivity and a polypeptide hydrogel suitable for application to a living body.

Polypeptide hydrogel and method for producing same

Polypeptide particles of the present invention are particles of a polypeptide derived from spider silk proteins, and have an average particle size of 1000 nm or less. A method for producing polypeptide particles of the present invention includes: a solution production step in which the polypeptide is dissolved in at least one solvent selected from the group consisting of DMSO, DMF, and these with an inorganic salt, so as to obtain a solution of the polypeptide; a step in which the solution produced in the solution production step is substituted with a water-soluble solvent so as to obtain an aqueous solution of the polypeptide; and a step in which the aqueous solution of the polypeptide is dried. Thereby, the present invention provides polypeptide particles suitable for application to a living body and capable of being applied to cosmetics, etc., while identifying the properties of the polypeptide particles, and a method for producing the same.

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Tsuruoka, Japan

Keisuke Morita