Characterization of gangliosides from bovine erythrocyte membranes

Two glucosamine-containing gangliosides, sialosylhexaglycosylceramides, were isolated from bovine erythrocyte membranes. Both gangliosides were hydrolyzed by neuraminidase isolated from Clostridium perfringens to become neutral hexaglycosylceramides. Based on the results of sequential enzymatic hydrolysis and gas chromatography-mass spectrometric analyses of the methylated sugars, the structures of these two gangliosides were shown to be NeuAcalpha2 leads to 3Galbeta1 leads to 4GlcNAcbeta1 leads to 3Galbeta1 leads to 4GlcNAcbeta1 leads to 3Galbeta1 leads to 4Glc-ceramide and NeuGcalpha2 leads to 3Galbeta1 leads to 4GlcNAcbeta1 leads to 3Galbeta1 leads to 4GlcNAcbeta1 leads to 3Galbeta1 leads to 4Glc-ceramide, respectively. In addition, N-acetyl- and N-glycolylneuraminosyllacto-N-neotetraosylceramides, and N-acetyl- and N-glycolylneuraminosyllactosylceramides were also found in bovine erythrocytes. The predominant fatty acids in these two gangliosides were C 22:0 and C 24:0. C-18 sphingosine was the major base detected.