CHEMOSELECTIVE REMOVAL OF PROTECTING GROUPS FROM O-GLYCOSYL AMINO-ACID AND PEPTIDE (METHOXYETHOXY)ETHYL ESTERS USING LIPASES AND PAPAIN

The selective C-terminal deprotection of O-glycopeptide (methoxyethoxy )ethyl esters is achieved under mild conditions (pH 6.6, 37 degrees C) by enzymatic hydrolysis using papain or lipase M from Mucor javanicus to give building blocks useful for chain-extending glycopeptide synth esis. On the other hand, the selective removal of acetyl protecting gr oups from the saccharide portion of glycopeptides is accomplished by a lternative enzymatic hydrolysis with lipase WG from wheat germ to furn ish model substrates for enzymatic glycosyl transfer reactions in orde r to extend the carbohydrate side chain of these conjugates.