A New Extended Globoglycolipid Carrying the Stage Specific Embryonic Antigen-1 (SSEA-1) Determinant in Mouse Kidney1

Two neutral glycolipids carrying the stage specific embryonic antigen-1 (SSEA-1) and SSEA-3 determinants, respectively, were purified from mouse kidney by a combination of column chromatographies and droplet counter-current chromatog-raphy. The structures of the glycolipids (GL-X and GL-Y) were determined by means of GLC, 1H-NMR spectroscopy, negative-ion fast atom bombardment mass spectrometry, a methylation study, and sequential degradation. GL-X was demon-strated to be galactosyl/?l-3globotetraosylceramide, the structure of which had already been characterized to be that of SSEA-3 by Kannagi et al. ((1983) /. Biol. Chem. 258, 8934-8942). GL-Y was a new glycolipid containing fucose, galactose, glucose, iV-acetylgalactosamine, and Ar-acetylg]ucosamine in a molar ratio of 1: 4: 1: 1: 1. The methylation study results indicated that it contained 3 mol of terminal sugars composed of 2 mol of galactose and 1 mol of fucose with two branching points at N-acetylgalactosamine and Ar-acetylglucosamine. From the data obtained by 'H-NMR spectroscopy, mass spectrometry, and a binding assay using an anti-SSEA-1 monoclonal antibody (PM81) cloned by Ball et al. ((1983) /. Immunol. 130, 2937-2941), we propose the structure of GL-Y to be Gal/?l-4GlcNAc/31-6GalNAc/?l-3Ga]al-4Gal/?l-4Glc/Sl-ceramide