链霉菌分解角蛋白的生化机制研究

对弗氏链霉菌Ｓ－２２１变种分解角蛋白的生化机制进行了初步研究。该菌在角蛋白底物作用下诱导产生胞外角蛋白酶。它是一种复合蛋白酶，含有二硫键还原酶和多肽水解酶等多种酶活性组分，其中，二硫键还原酶是分解角蛋白的关键酶，二硫键还原酶首先作用于角蛋白中的二硫键，使角蛋白高级结构解体形成变性角蛋白，然后变性角蛋白在多肽水解酶的共同作用下逐步水解成多肽，寡肽和游离氨基酸，使角蛋白彻底分解。在角蛋白分解过程中，角蛋白中的硫也随之转化成巯基化合物，Ｈ２Ｓ和硫酸盐３种含硫化合物存在于分解产物中。

Study on the Biochemical Mechanism of Degrading Keratinsby Streptomyces fradiae *

The biochemical mechanism of degrading keratins by S.fradiae var S-221 was primarily studied.On the condition that substrate,keratins.exists,S.fradiae var S-221 is induced to produce exo-keratinase,which is a multiproteinasr,containing disulfide bonds reductase,which is a key enzyme degrading keratins,then,with polypeptidic hydrolytase,graduately hydrolyzates denatured keratins into polypeptides,oligopeptides and free amino acids,so that keratins have been decomposed completely.Sulfur in the keratins was transfered into sulfhydryl compounds,H 2S and sulfates in the course of keratinolysins.