The blood group U antigen is not located on glycophorin B.
Erythrocytes from twelve individuals with the S-s-U- phenotype and from ten with the S-S-U+ phenotype were analyzed and compared to control cells with S+/s+U+ determinants. No red cell abnormality was detected in S-s-U+ or S-s-U- carriers. Sialic acid content was similar (P greater than 0.05) for S-s-U+ and S-s-U- erythrocytes (74.6 +/- 7.14 and 71.4 +/- 8.53 nmol/10(9) red blood cells, respectively) but significantly less (P less than 0.001) than controls with 89.5 +/- 11.4 nmol/10(9) red blood cells, n = 16. Fluorographs of SDS-polyacrylamide gels showed no glycophorin B in membranes from S-s-U+ and S-s-U- erythrocytes labeled with NaB3H4. Glycophorins were extracted from red cell membranes in chloroform/methanol, labeled with 125I and analyzed by SDS-polyacrylamide gel electrophoresis. Periodic acid Schiff stain and autoradiographs of these gels also showed absence of glycophorin B in both S-s-U+ and S-s-U- cells. These findings suggested that the U antigen is not located on glycophorin B. This hypothesis was tested by determining blood group antigenicity on red cell membranes and on extracted sialoglycoproteins by the hemagglutination inhibition technique. Although U and S/s activities were detected in control red cell membranes, extracted glycoproteins demonstrated S/s activity but no U activity. Together the data indicate that both S-s-U+ and S-s-U- erythrocytes lack glycophorin B and that the U antigen is not located on glycophorin B. This deletion does not seem to affect the structure-function of the red cell.
D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology*; D006021:Glycophorins / Q000032:analysis*; D006023:Glycoproteins / Q000097:blood / Q000276:immunology; D006801:Humans; D007519:Isoantigens / Q000032:analysis*; D008951:MNSs Blood-Group System / Q000276:immunology*; D008565:Membrane Proteins / Q000097:blood; D019158:N-Acetylneuraminic Acid; D010641:Phenotype; D012794:Sialic Acids / Q000097:blood; D012795:Sialoglycoproteins / Q000032:analysis*
D006021:Glycophorins; D006023:Glycoproteins; D007519:Isoantigens; D008951:MNSs Blood-Group System; D008565:Membrane Proteins; D012794:Sialic Acids; D012795:Sialoglycoproteins; D019158:N-Acetylneuraminic Acid