A Revised Structure for the Disialosyl Globo-Series Gangliosides of Human Erythrocytes and Chicken Skeletal Muscle

Disialosyl globo-series gangliosides have previously been isolated from chicken skeletal muscle (E. L. Hogan, R. D. Happel, and J.-L. Chien (1982) Adv. Exp. Med. Biol. 152, 273-278; S. Dasgupta, J.-L. Chien, E. L. Hogan, and H. van Halbeek (1991) J. Lipid Res. 32, 499-506) and human erythrocytes (S. K. Kundu, B. E. Samuelsson, I. Pascher, and D. Marcus (1983) J. Biol. Chem. 258, 13857-13866). In both cases, the structure of this ganglioside was proposed to be NeuAcα2 → 3(NeuAcα2 → 6)Galβ1 → 3GalNAcβ1 → 3Galα1 → 4Galβ1 → 4Glcβ1 → 1Cer (V3NeuAcV6NeuAcGb5Cer). We have reinvestigated the human erythrocyte antigen and now propose an alternative structure differing in the location of the NeuAcα2 → 6 residue: NeuAcα2 → 3Galβ1 → 3(NeuAcα2 → 6)GalNAcβ1 → 3Gal α1 → 4Galβ1 → 4Glcβ1 → 1Cer (V3NeuAcIV6NeuAcGb5Cer). This novel structure is supported by results of 1H-NMR spectroscopy, negative ion fast atom bombardment mass spectrometry, and methylation linkage analysis with capillary gas chromatography-mass spectrometry in both electron impact and chemical ionization modes. Furthermore, based on new results from negative ion fast atom bombardment mass spectrometry and linkage analysis, we propose that the chicken skeletal muscle antigen also has this revised structure, differing only in ceramide composition. The terminal tetrasaccharide of these gangliosides is identical to that of GD1α NeuAcα2 → 3Galβ1 → 3(NeuAca2 → 6)GalNAcβ1 → 4Galβ1 → 4Glcβ1 → 1Cer(IV3NeuAcIII6NeuAcGg4Cer), previously identified in a rat ascites hepatoma cell line (T. Taki, Y. Hirabayashi, H. Ishikawa, S. Ando, K. Ken, Y. Tanaka, and M. Matsumoto (1986) J. Biol. Chem. 261, 3075-3078) and a murine lymphoma cell line with low metastatic potential (K. Murayama, S. B. Levery, V. Schirrmacher, and S. Hakomori (1986) Cancer Res. 46, 1395-1402), although they appear to be immunologically distinct.