ENZYMATIC-SYNTHESIS OF PARA-NITROPHENYL 3(5)-O-BETA-N-ACETYLGLUCOSAMINYL-ALPHA-MALTOPENTAOSIDE BY LYSOZYME - A NOVEL SUBSTRATE FOR HUMAN AMYLASE ASSAY

Transglycosylation from di-N-acetylchitobiose to the 3-position at the nonreducing end glucosyl group of p-nitrophenyl α-maltopentaoside was regioselectively induced through the use of hen egg-white lysozome. The enzyme formed p-nitrophenyl 35-O-β-N-acetylglucosaminyl-α-maltopentaoside (5% of the enzyme-catalyzed net decreased of p-nitrophenyl α-maltopentaoside) from di-N-acetylchitobiose as a donor and p-nitrophenyl α-maltopentaoside as an acceptor. The rate of the transglycosylation depended on the concentration of substrate, the temperature and the pH. The hydrolytic actions of human pancreatic and salivary α-amylase on this derivative were examined. The maltopentaoside derivative was shown to be useful as a substrate for α-amylase assay through a coupled reaction involving α-D-glucosidase and glucoamylase. © 1990.