Blood-group-ABH antigens of human erythrocytes. Quantitative studies on the distribution of H antigenic sites among different classes of membrane components.
The contribution of blood-group-active glycolipids and glycoproteins to the blood-group-ABH character of human erythrocytes was investigated. For that purpose the blood-group-H sites of human O cells were converted in vitro into group-A sites by transfer of alpha-N-acetyl-D-[14C]galactosamine residues with the aid of the blood-group-A gene-dependent alpha-N-acetylgalactosaminyl transferase prepared from human A1 plasma. Upon partition of the red cell membranes between water and organic solvent, about 5% of the label was found in the organic phase and about 20% in the water phase, thus reflecting the distribution of blood-group antigenic sites between glycosphingolipids with short carbohydrate chains and polyglycosylceramides, respectively. The fact that about 70% of the radioactivity remained tightly bound to the membranes and could only be released by treatment with pronase provided good evidence that the bulk of blood-group-H determinants is bound to glycoprotein material. Following these results it can thus be assumed that blood-group-ABH activity of human erythrocytes is determined preferentially by group-specific glycoproteins rather than glycolipids.
D000017:ABO Blood-Group System; D000939:Epitopes; D004910:Erythrocyte Membrane / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology*; D005646:Fucosyl Galactose alpha-N-Acetylgalactosaminyltransferase / Q000097:blood; D006017:Glycolipids / Q000097:blood; D006023:Glycoproteins / Q000097:blood; D006028:Glycosphingolipids / Q000097:blood; D006801:Humans; D008563:Membrane Lipids / Q000097:blood; D008565:Membrane Proteins / Q000097:blood; D011402:Pronase; D012204:Rh-Hr Blood-Group System; D014536:Uridine Diphosphate N-Acetylgalactosamine
D000017:ABO Blood-Group System; D000939:Epitopes; D006017:Glycolipids; D006023:Glycoproteins; D006028:Glycosphingolipids; D008563:Membrane Lipids; D008565:Membrane Proteins; D012204:Rh-Hr Blood-Group System; D014536:Uridine Diphosphate N-Acetylgalactosamine; D005646:Fucosyl Galactose alpha-N-Acetylgalactosaminyltransferase; D011402:Pronase