摘要 |
Mutant glycosidases in which the amino acid in the active site that serves as the acid, base or acid/base-catalyst is converted from a carboxylic acid to some other amino acid (for example to a simple alkyl, as in alanine or glycine) can catalyze the reaction of a thiosugar acceptor and an activated donor to form a thioglycoside. The "thioglycoligases" represent a novel class of mutant enzymes, and represent a first aspect of the invention. Thioglycoligases can be used in accordance with the method of the invention to couple a thiosugar acceptor and an activated donor to form a thioglycoside. By selection of the donor and acceptor species, as well as the specific enzyme employed, thioglycosides of different structure and stereochemistry can be obtained. |