Schistosoma mansoni cercarial glycolipids are dominated by Lewis X and pseudo-Lewis Y structures

The oligosaccharide structures of glycolipids from cercariae of the human blood fluke, Schistosoma mansoni, were analyzed in the form of their corresponding, pyridylaminated oligosaccharides by methylation analysis, partial hydrolysis, exoglycosidase treatment, on-target exoglyco-sidase cleavage and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The six, dominant chemical structures present have been determined as: GalNAc(beta1-4)Glc1-ceramide; GlcNAc(beta1-3)Gal-NAc(beta1-4)Glc1-ceramide; Gal(beta1-4)GlcNAc(beta1-3)Gal-NAc(beta1-4)Glc1-ceramide; Gal(beta1-4)[Fuc(alpha1-3)]Glc-NAc(beta1-3)Gal-NAc(beta1-4)Glc1-++ +ceram ide (Lewis X pentasaccharide structure); Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)Glc-NAc(beta1-3)GalNAc(beta 1-4)Glc1-ceramide (Lewis X hexa-saccharide structure); and, Fuc(alpha1-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)GalNAc(beta1-4 )Glc1-ceramide (pseudo-Lewis Y hexasaccharide structure). These structures belong to the characterized schisto-series of protostomial glycosphingolipids. The Lewis X and pseudo-Lewis Y glyco-lipids are stage-specifically expressed by the cercarial life-cycle stage, and not by the adult or egg.