Characterization of GMID in Mouse Spleen1 Kyoko NAKAMURA, Yasuhiro HASHIMOTO, Minoru SUZUKI,

Two GMib gangliosides (IV-sialosylgangliotetraosylceramide) containing either N-glycolylneuraminic acid or JV-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, sus-ceptibility to sialidase and immunobinding activity toward anti-gangliotetraosylcer-amide antibody. The structure of GMib containing iV-glycolylneuraminic acid was further confirmed by methylation analysis. GMI gangliosides containing either N-glycolylneuraminic acid or iV-acetylneuraminic acid were also purified and chara-cterized by thin layer chromatography, sugar analysis and sialidase treatment. As a result, the presence of four kinds of monosialoganglioside with a gangliotetraosyl core structure, GMi(NeuAc), GMiCNeuGc), GMib(NeuAc), and GMib(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 sialosylneolactotetraosyIceramide(NeuGc)