Enzymatic synthesis of galactose-containing disaccharides employing beta-galactosidase from Bacillus circulans

Gal beta 1-->4 disaccharide structures are vital core units of the oligosac charide components of glycoconjugates. P-Galactosidase from Bacillus circul ans (E.C.3.2.1.23) catalyses the transfer of galactose from a donor structu re such as Gal beta OpNP to various GlcNAc and galactose derivatives, formi ng p1-->4 Linkages. The synthesis of several biologically relevant disaccha rides {Gal beta 1-->4GlcNAc alpha OAll (3), Gal beta 1-->4GlcNAc beta All ( 5), Gal beta 1-->Gal alpha OAll (10), Gal beta 1-->4Gal beta OAll (12), Gal beta 1-->4Gal beta SPh (14), Gal beta 1-->4Gal beta OpNP (16) and the tris accharide Gal beta 1-->4Gal beta 1-->4Gal beta OpNP (18)} has been achieved in 30-66 % yield by application of this enzyme.