Ganglio-N-tetraosylceramide (GA1) of bovine and human brain. Molecular characterization and presence in myelin.

During our studies of bovine brain neutral glycosphingolipids (Ngsl's), we have purified a compound that co-migrates on thin-layer chromatogram with standard GA1 (purified by acid hydrolysis of GM1) and close to penta- (nLc5Cer) glycosylceramide from bovien erythrocytes. The structure of the purified Ngsl from brain has been established by permethylation and by stepwise exoglycosidase hydrolysis. 600 MHz 1H NMR spectroscopy of the oligosaccharide obtained from the Ngsl after endoglycoceramidase hydrolysis confirms the structure as ganglio-N-tetraosylceramide (GgOse4Cer or GA1) as Gal beta 1----3GalNAc beta 1----4Gal beta 1----4Glc beta 1----1Cer. We have identified GA1 in bovine, rat and human brain and myelin by TLC-immunostaining with monospecific anti-GA1 antiserum.