Cellulase-catalysed glycosylation reactions: simple route towards a highly selective synthesis of oligosaccharides

Abstract

Cellulase (EC 3.2.1.4) can be used for the enzyme-catalysed synthesis of oligosaccharides in a mixed buffer/organic solvent system. Besides glucopyranosides and cellooligosaccharides, non -glucosidic saccharides and modified glucoses as glycosyl acceptors also react with β-lactosyl fluoride as glycosyl donor. The reaction proceeds in a completely stereo- and regio-specific manner, giving rise to coupling products having β(1→4) glycosidic bonds exclusively. Based on these results, a model for the active site of cellulase (Trichoderma viride) and the orientation of the donor and acceptor therein is proposed.