SOLID-PHASE ENZYMATIC-SYNTHESIS OF A LEWIS A TRISACCHARIDE USING AN ACCEPTOR REVERSIBLY BOUND TO SEPHAROSE

The disaccharide 2-aminoethyl (1-->3)-2-acetamido-2-deoxy-beta-D-gluco pyranoside was reacted with thiobutyrolactone to give a disaccharide w ith a thiol group on the aglycone. This disaccharide was reacted with activated Thiopropyl Sepharose, which gave a disaccharide bound to Sep harose via a disulphide bond. Enzymatic fucosylation, using GDP-fucose and partially purified human milk fucosyltransferase, gave a trisacch aride in good yield, which was cleaved from Sepharose by treatment wit h mercaptoethanol or dithiothreitol.