Isolation and Characterization of Rat Intestinal 1, 3-α-D-Glucosaccharide Hydrolase

Abstract

A glucosidase having specificity towards α-(1→2)-, α-(1→3)-, and α-(1→4)-D-glucosidic linkages, was solubilized from the rat small intestinal mucosa by papain treatment. The glucosidase was purfied in a highly homogeneous state by successive chromatographies on DEAE-Sephacel and Sepharcyl S-400 columns. The molecular weight of purified enzyme was 300,000, as estimated by Sephacryl S-400 gel filtration, and its isoelectric point was found to be 4.5.

The purified enzyme hydrolyzed kojibiose, nigerose, O-α-D-glucopyranosyl-(1→3)-O-α-D-glucopyranosy-(1→4)-O,α-D-glucopyranose ( elsinotriose ), maltose, maltotriose and amylose at a relative hydrolysis rate of 26, 18, 65, 100, 98, and 4, respectively. However, α, α-trehalose, panose, sucrose, isomaltose, maltitol and p-nitrophenyl α-D-glucopyranoside were not hydrolyzed.