| abstract |
(57) [Summary] [Purpose] A film, fiber, sponge, etc. having a thiol group that can crosslink with a peptide chain of an appropriate length that will have suitable strength when processed into film, fiber, etc. As a material for or as a microcapsule wall Provided is a keratin fragment which can be suitably used as a medical / agrochemical base material and a cosmetic base material. [Structure] Reduced keratin obtained by reducing a substance containing keratin is hydrolyzed with a proteolytic enzyme, and the proteolytic enzyme is inactivated during the hydrolysis or separated from the reaction system to stop the hydrolysis. The average molecular weight of 3,000 to 30,000 and amino acid 1 A keratin fragment with 4-16 cysteines per 00 residue is produced. |