| 摘要 |
Mutant glycosidase enzymes are formed in which the normal nucleophilic amino acid within the active site has been changed to a non-nucleophilic amino acid. These enzymes cannot hydrolyze disaccharide products, but can still form them. Using this enzyme, oligoeaccharides are synthesized by preparing a mixture of an alpha -glycosol fluoride and a glycoside acceptor molecule; enzymatically coupling the alpha -glycosol fluoride to the glycoside acceptor molecule to form a glycosol glycoside product using the mutant glycosidase enzyme; and recovering the glycosyl product. The enzymes to be used are mutant forms of human or porcine alpha -amylase or yeast alpha -glucosidose having two catalytically active amino acids with carboxylic acid side claims within the active site, in the wild-type enzyme, with one of these amino acids being replaced by a different amino acid. |
