AMINO ACID RESIDUES IN CONSERVED REGION II INVOLVED IN SPECIFIC FUNCTION OF EUROPEAN HONEYBEE (APIS MELLIFERA) α-GLUCOSIDASE ISOZYMES

摘要

European honeybees (Apis mellifera) possess three α-glucosidase isozymes (HBG-I, HBG-II and HBG-III), all of which belong to glycoside hydrolase family 13 (GH13). In spite of their high sequence similarity, three isozymes exhibit distinct enzymatic properties in substrate specificity, transglucosylation ratio, regioselectivity, and so on. In this presentation, we demonstrate the involvement of the residues in the conserved region II, located in the proximity of nucleophile catalyst Asp223 in both HBG-II and HBG-III, in the specific characteristics of the isozymes.