N-ACETYLGLUCOSAMINYL DISACCHARIDE AND TRISACCHARIDE FORMATION THROUGH LYSOZYME-CATALYZED TRANSFER-REACTION

A hen egg-white lysozyme produced regioselectively 4-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-D-mannose and p-nitrophenyl 4-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-<beta)-D-mannopyranoside through a transglycosylation reaction fron N,N'-diacetylchitobiose and respectively mannose and p-nitrophenyl beta-D-mannopyranoside. These enzyme reactions were efficient enough to allow the one-pot preparation of the desired disaccharide. When p-nitrophenyl 2-acetamido-2-deoxy-alpha-D-glucopyranoside was the acceptor, the enzyme catalyzed the formation of a beta-(1-3)-linked disaccharide glycoside (p-nitrophenyl 2-acetamido-2-deoxy-3-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-alpha-D-glucopyranoside) with its beta-(1-4)-linked isomer. This is also the case for the formation of p-nitrophenyl 3-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-alpha-maltoside with p-nitrophenyl alpha-maltoside acceptor. The results show that the anomeric configuration of the glycosidic linkage in the glycosyl acceptors had a pronounced effect on the position of transglycosylation.