| Abstract: | A new ganglioside showing choleragenoid-binding activity was purified from mouse spleen and characterized. From the results of sugar-composition analysis, enzymatic hydrolysis, a permethylation study, 1H-NMR spectroscopy, and negative-ion fast atom bombardment mass spectrometry, the structure of the ganglioside was determined to be as follows: Gal beta 1-3GalNAc beta 1-4Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1-1'ceramide 3----NeuGc alpha 2 This ganglioside contains a terminal tetrasaccharide structure identical with that of II3NeuGc alpha-Gg4Cer (GM1(NeuGc]. By means of a TLC-immunobinding assay and an enzyme-linked immunosorbent assay, the ganglioside was demonstrated to have almost the same choleragenoid-binding activity as GM1. Another ganglioside, that migrated faster than the new choleragenoid-binding ganglioside, was also purified from the same source material and identified as IV4GalNAc beta,IV3NeuGc alpha-Gg4Cer (GalNAc-GM1b(NeuGc]. Since, in the previous study, we demonstrated the existence of IV3NeuGc alpha-Gg4Cer (GM1b(NeuGc] in mouse spleen (Nakamura, K. et al. (1984) J. Biochem. 96, 949-957), the results of this study suggest that the new choleragenoid-binding ganglioside is synthesized from GM1b(NeuGc) through GalNAc-GM1b(NeuGc). |
