Stepwise transfer of α-d-Galp-(1→3)-β-d-Galp-(1→4)-β-d-GlcpNAc sequences to 3-OH and 6-OH of distal galactose residues in bi-, tri-, and tetra-antennary asialo-glycans of N-linked complex type

The hydroxyl groups 3 and 6 of distal galactose units in bi-, tri-, and tetra-antennary asialo-glycans of N-linked complex type were substituted stepwise by transferase reactions with the sequence α-d-Galp-(1→3)-β-d-Galp-(1→4)-β-d-GlcpNAc. The products of each transferase reaction were purified chromatographically and the structures were confirmed by 1H NMR spectroscopy Molecular weights of the final products were determined by matrix-assisted laser-desorption mass spectrometry (MALDI-MS).