Hydrolase-catalyzed beta-mannosylations

Transmannosylations catalysed by beta-mannosidase from snail viscera or bet a-galactosidase from Aspergillus oryzae were accomplished with 4-nitropheny l beta-D-mannopyranoside as donor substrate. With suitable hydrophobic acce ptor molecules preferentially beta 1-4-linked disaccharides were obtained. The activities of both glycosidases in buffer cosolvent mixtures were deter mined, and conditions for their immobilization were elaborated and optimize d. A model of the enzymic transfer mechanism is suggested.