Characterization of the oligosaccharide structures on bee venom phospholipase A2

Abstract The N -linked oligosaccharide structurs on bee venom phospholipase A 2 were investigated. The oligosaccharides on purified phospholipase A 2 were released by hydrazinolysis and labeled in vitro by reduction with NaB 3 H 4 . Following purification, the labeled oligosaccharides were characterized by size exclusion chromatography in combination with digestion with specific glycosidases. Linkage positions were determined by methylation analysis. Four types of structures were identified on the molecule, all of which were of truncated high-mannose type and none of which contained any α-(1 → 2)-linked mannose residues. The majority of the structures were Man 3 oligosaccharides with (43%) or without (38%) a fucose residue linked α-(1 → 6) to the reducing N -acetylglucosamine. The remaining 19% of the oligosaccharides on the molecule were identified as a Man 5 oligossacharide without core fucose (9.6%) and a core-fucosylated Man 4 structure (9.2%).