Purification and Characterization of Novel Chitinases from Steptomyces griseus HUT 6037

概要

論文の詳細を見る
Two chitinases, C-1 and C-2,were purified form the culture superantant of Streptomyces griseus HUT 6037 by ammonium sulfate precipitation, Butyl-Toyopearl 650M chromatography, and chromatofocusing. Both enzymes had a molecular weight estimated to be 27,000 by SDS polyacrylamide gel electrophoresis, while their pIs were 7.7 and 7.3,respectively. The enzymes were active from pH 4.5 to 6.0 and their optimum temperature was 55℃. They were stable between pH 6.5 and 10.0 and at temperatures below 50℃. Chitinases C-1 and C-2hydrolyzed chitin, colloidal chitin, glycol chitin, carboxymethyl chitin, 53% deacetylated chitosan, and (GlcNAc)_<3-6>, but did not hydrolyze 96% deacetylated chitosan and (GlcN)_n. The hydrolyzates of 53% deacetylated chitosan by these enzymes were separated by CM-Sphadex C-25 column chromatography. The products were analyzed structurally to elucidate the specificity of the chitinases.The oligasaccharides isolated had GlcNAc as the nonreducing end GlcNAc or GlcN as the reducing end residues. These results indicate that enzymes cleave both the N-acetyl-β-D-glucosaminidic and the β-glucosaminidic linkages in partially N-anetylated chitosan molecules.
1995-08-25