Transgalactosylation Catalyzed by α-Galactosidase from Candida guilliermondii H-404

Abstract

The thermostable α-galactosidase from Candida guilliermondii H-404 synthesized self transfer products in the absence of a suitable acceptor. The main self transfer product, using melibiose as a donor substrate, was O-α-D-galactosyl-(1, 6)-O-α-D-galactosyl-(1, 6)-D-glucose. This enzyme had a wide acceptor specificity. D-Glucose, D-galactose, maltose, maltitol, and 1, 4-butandiol were the most effective acceptors in the transgalactosylation catalyzed by this enzyme. The enzyme could also transfer α-galactosyl residues to pentoses (L-arabinose, D-xylose, and D-ribose) and methyl pentoses (D-fucose and L-rhamnose). The main transfer products to lactose, maltose, and sucrose as acceptors were identified as O-α-D-galactosyl-(1, 6)-O-β-D-galactosyl-(1, 4)-D-glucose, O-α-D-galactosyl-(1, 6)-O-α-D-glucosyl-(1, 4)-D-glucose, and O-α-D-ga-lactosyl-(1, 6)-O-α-D-glucosyl-(1, 2)-β-D-fructoside (raffinose), respectively.