NUCLEAR OVERHAUSER EFFECT INVESTIGATION ON GM1 GANGLIOSIDE CONTAININGN-GLYCOLYL-NEURAMINIC ACID (II(3)NEU5GCGGOSE(4)CER)

The conformational properties of the oligosaccharide chain of GM1 gang lioside containing N-glycolyl-neuraminic acid, a-Neu5Gc-(2-3)]-beta-Ga l-(1-4)-beta-Glc-(1-1)-Cer, were studied through NMR nuclear Overhause r effect investigations on the monomeric ganglioside in dimethylsulfox ide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core -bet a-GalNAc-(1-4)-[alpha-Neu5Gc-(2-3)]-beta-Gal- were found to fix the re lative orientation of the three saccharides, while the glycosidic link age of the terminal beta-Gal- was found to be quite mobile as the beta -Gal-(1-3)-beta-GalNAc- disaccharide exists in different conformations . These results are similar to those found for two GM1 gangliosides co ntaining N-acetyl-neuraminic acid and neuraminic acid [1].