Spiber Inc.

Shinya Murata

Kaori Sekiyama

Mizuki Ishikawa

Kazuhide Sekiyama

Ryota Sato

Junichi Sugahara

Kazuko Otomo

Sugahara Junichi

A film of the present invention contains a polypeptide derived from spider silk proteins. The decomposition temperature of the film is 240 to 260&#xb0; C. The film absorbs ultraviolet light having a wavelength of 200 to 300 nm and has a light transmittance of 85% or more at a wavelength of 400 to 780 nm. The film is transparent and colorless in a visible light region. A method for producing a film of the present invention includes: dissolving a polypeptide derived from spider silk proteins in a dimethyl sulfoxide solvent to prepare a dope; and cast-molding the dope on a surface of a base. Thus, the present invention provides a spider silk protein film that can be formed easily and has favorable stretchability, and a method for producing the same.

Spider silk protein film, and method for producing same

An artificial polypeptide fiber of the present invention is an artificial fiber containing a polypeptide as a main component, and has a stress of 350 MPa or more and a toughness of 138 MJ/mor more. A method for producing an artificial polypeptide fiber of the present invention is a method for producing the artificial polypeptide fiber obtained by spinning a spinning solution () containing a polypeptide derived from natural spider silk proteins and performing drawing of at least two stages. The drawing of at least two stages includes a first-stage drawing () in wet heat and a second-stage drawing () in dry heat. Thereby, the present invention provides high-toughness artificial polypeptide fibers having favorable stress and rupture elongation, and a method for producing the same.

Artificial polypeptide fiber and method for producing the same

A polypeptide solution of the present invention is a polypeptide solution in which a polypeptide derived from natural spider silk proteins is dissolved in a solvent. The solvent contains at least one selected from the following (i)-(iii): (i) DMSO; (ii) DMSO with an inorganic salt; and (iii) DMF with an inorganic salt. Further, in the present invention, an artificial polypeptide fiber is obtained by: using the polypeptide solution as a dope solution; and extruding the dope solution from a spinneret into a desolvation bath so as to eliminate the solvent from the dope solution and form a fiber to produce an undrawn yarn. Moreover, in the present invention, a polypeptide is purified by subjecting the polypeptide solution to heat treatment and thereafter removing an undissolved substance therefrom. Thus, the present invention provides the polypeptide solution whose solute has high solubility and solvent itself is low cost, and that allows dissolution at high temperatures and has high safety: a method for producing an artificial polypeptide fiber: and a method for purifying a polypeptide.

Polypeptide solution, artificial polypeptide fiber production method and polypeptide purification method using same

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Tsuruoka, Japan

Shinya Murata