Molecular characterization and immunohistochemical localization of IV(4)GalNAcGgOse(4)Cer: a naturally occurring novel neutral glycosphingolipid in bovine brain

A pair of never neutral glycosphingolipids (Ngsls) has been identified in b ovine brain. Their mobilities on thin layer chromatography were slightly di fferent from a standard pentaglycosglceramide (nLcOse(5)Cer from bovine ery throcytes), The compounds were purified to homogeneity by column chromatogr aphy. Their fatty acid and base compositions, their monosaccharide composit ions and sugar linkage positions were determined by gas-liquid chromatograp hy/mass spectrometry. Carbohydrate sequence analysis by H-1 NMR spectroscop y and stepwise exoglycosidase digestion indicated the following pentaglycos yl structure for the oligosaccharide moiety of both Ngsls: GalNAc beta 1-4G al beta 1-3GalNAc beta 1-4Gal beta 1-4Glc. The two Ngsls (abbreviated as IV (4)GalNAcGgOse(4)Cer or GalNAc-GA1), differ in their ceramide compositions, having d18:0 and d18:1 sphingosine as their long chain bases. A monospecif ic polyclonal anti-GalNAc-GA1 antibody, prepared in rabbit and purified by affinity chromatography, stained the neurons of cerebral cortex and cerebel lum including Purkinje cells in adult rat brain, indicating that the novel GalNAc-GA1 is associated with cerebellar and other neurons in vertebrate ce ntral nervous system.