1. Characterization of blood group ABO(H)-active gangliosides in type AB erythrocytes and structural analysis of type A-active ganglioside variants in type A human erythrocytes
- Author
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Yasunori Kushi, Kiyohiro Watanabe, Shizuo Handa, Shinobu Watarai, Toshio Ariga, Motomasa Shimizu, and Takeshi Kasama
- Subjects
Antigenicity ,Erythrocytes ,medicine.drug_class ,Molecular Sequence Data ,Biophysics ,In Vitro Techniques ,Monoclonal antibody ,Biochemistry ,Epitope ,ABO Blood-Group System ,Epitopes ,Mice ,chemistry.chemical_compound ,Column chromatography ,Gangliosides ,ABO blood group system ,medicine ,Animals ,Humans ,Molecular Biology ,Ganglioside ,Antibodies, Monoclonal ,Chromatography, Ion Exchange ,N-Acetylneuraminic Acid ,Immune complex ,Sialic acid ,Carbohydrate Sequence ,chemistry - Abstract
Several monosialogangliosides containing the type A-active epitope have been detected in type A erythrocytes on immunological analysis with a monoclonal antibody, and three of them were purified by repeated silica bead column chromatography and by scraping from the TLC plate. Two of these A-active gangliosides were characterized by methylation analysis by GC/MS, negative SIMS, MALDI-TOF/MS, proton nuclear magnetic resonance spectroscopy, and immunological assays, and their structures were concluded to be as follows. A-active ganglioside I: Download : Download full-size image A-active ganglioside II: Download : Download full-size image The reactivity of the purified gangliosides to the anti-A monoclonal antibodies (mAbs) exhibited enhancement after removal of the sialic acid. Therefore, the sialic residue has been shown to inhibit the binding to the terminal A-active epitope through the formation of an immune complex. To confirm the presence of A- (including S-A-I, -II and -III) and B-active gangliosides, the reactivity of anti-A and -B mAbs were investigated using total gangliosides from type A, -B and -AB erythrocytes on TLC plate. The results were that the gangliosides from types A and AB showed positive reaction to anti-A mAbs, whereas in the anti-B mAbs binding the gangliosides from types B and AB were positive. Thus, it revealed that A-active gangliosides were present in type A and -AB, and B-active gangliosides in types B and AB. As there was no difference in respective gangliosides on type AB erythrocytes of 22 individuals, both A- and B-active gangliosides are equally present in type AB erythrocytes. The biological significance of these A- and B-active ganglioside variants remains vague at present. As these molecules exhibit different reactivities to the anti-A mAbs, it is very likely that they can regulate the antigenicity of the A-epitope on the cell surface.
- Published
- 2001