Incompatible blood-group A determinants in tumoral mucins. Isolation of oligosaccharides having a 2-acetamido-2-deoxy-alpha-D-galactopyranosyl group at the non-reducing end.
Two glycopeptide fractions were obtained from pseudomyxomatous mucins secreted by an ovarian cystadenocarcinoma from a female having blood-group B, and by an appendix tumor from a male having blood-group O. The carbohydrate and amino acid content of these fractions suggests the presence of numerous carbohydrate side-chains linked through O-glycosyl bonds to a peptide core rich in threonine and proline. The two glycopeptide fractions exhibit compatible B- and H-blood-group activities. They are reactive towards Dolichos biflorus lectin and human anti-A agglutinins, and so exhibit an incompatible A activity. Alkali-borohydride degradation of Pronase-digested glycopeptides gave dialyzable oligosaccharides that were purified and shown to possess 2-acetamido-2-deoxygalactitol at the terminal reducing-end. 2-Acetamido-2-deoxyglucose, galactose, fucose, and neuraminic acid were absent, or present, in variable proportions. Four oligosaccharides containing 2-acetamido-2-deoxy-D-galactose residues were reactive towards Dolichos biflorus lectin and human anti-A agglutinins, indicating the presence, at the nonreducing end, of a 2-acetamido-2-deoxy-alpha-D-galactopyranosyl group, responsible for blood-group A activity.
D000017:ABO Blood-Group System / Q000276:immunology*; D000116:Acetylgalactosamine / Q000032:analysis*; D000596:Amino Acids / Q000032:analysis; D003536:Cystadenocarcinoma / Q000276:immunology*; D000939:Epitopes / Q000032:analysis*; D005260:Female; D005688:Galactosamine / Q000031:analogs & derivatives*; D006801:Humans; D009077:Mucins / Q000276:immunology*; D009844:Oligosaccharides / Q000032:analysis; D010051:Ovarian Neoplasms / Q000276:immunology*
D000017:ABO Blood-Group System; D000596:Amino Acids; D000939:Epitopes; D009077:Mucins; D009844:Oligosaccharides; D005688:Galactosamine; D000116:Acetylgalactosamine