α-Galactosidases and their applications in biotransformations

Abstract

α-d-Galactosidases (α-d-galactoside galactohydrolase, E.C. 3.2.1.22) are exoglycosidases, which in vivo catalyze the hydrolysis of simple and complex oligo- and polysaccharides containing terminal α-d-galactosyl groups. A number of industrial applications of α-d-galactosidases are known, mainly in the sugar industry, pulp and paper industry or medicine. Although α-d-galactosidases occur in all living systems, microbial and possibly plant enzymes are preferred for practical applications. The regioselectivity of glycosidases is somewhat poor. Selective protection of oligosaccharides and development of new modified donors/acceptors is a promising method to overcome this problem. Genetic engineering has enabled the creation of glycosynthases from the hydrolytic glycosidases, which are highly complementary to glycosyltransferases. The present review summarizes recent advances in the application of α-d-galactosidases in synthetic and biotransformation applications.

• α-Galactosidase
• enzyme
• transglycosylation
• purification
• application
• directed evolution
• unnatural substrates