Two GM1b gangliosides (IV-sialosylgangliotetraosylceramide) containing either N-glycolylneuraminic acid of N-acetylneuraminic acid at the terminal galactose of gangliotetraosylceramide were found in the ICR mouse spleen. Their structures were characterized by the behavior on thin layer chromatograms, sugar composition, susceptibility to sialidase and immunobinding activity toward anti-gangliotetraosylceramide antibody. The structure of GM1b containing N-glycolylneuraminic acid was further confirmed by methylation analysis. GM1 gangliosides containing either N-glycolylneuraminic acid or N-acetylneuraminic acid were also purified and characterized by thin layer chromatography, sugar analysis and sialidase treatment. As a result, the presence of four kinds of monosialoganglioside with a gangliotetraosyl core structure, GM1(NeuAc), GM1(NeuGc), GM1b(NeuAc), and GM1b(NeuGc), were found to exist in the ICR mouse spleen. These four gangliosides accounted for about 50% of the spleen monosialoganglioside content. Additional four gangliosides in the monosialoganglioside fraction were tentatively characterized as GM3(NeuAc), GM3(NeuGc), GM2(NeuGc), and sialosylneolactotetraosylceramide(NeuGc).
Characterization of GM1b in mouse spleen. Publishing Authors By Initials