title: Blood group MNSs-active sialoglycoproteins of the human erythrocyte membrane.
abstract: The human erythrocyte membrane contains at least four different PAS-staining sialic acid-rich glycoproteins. The major sialoglycoprotein, which carries blood group M or N antigen activity, has been extensively characterized. The Ss antigens are located on a minor sialoglycoprotein, which also has "N' activity. The amino acid sequence at positions 1 and 5 of these glycoproteins correlates with the presence of M or N antigen activity. Little is known about the other minor sialoglycoproteins (beta and gamma). Membranes from erythrocytes of type (En(a-)Fin lack the major MN-active sialoglycoprotein; those from S-s-erythrocytes lack normal Ss-active sialoglycoproteins, although they contain an abnormal component that may be an altered Ss glycoprotein. Mk Mk cells lack both the MN- and Ss-active glycoproteins. These sialoglycoprotein-deficient cells are found in apparently healthy individuals. The sera of individuals with sialoglycoprotein-deficient cells may contain antisialoglycoprotein antibody, which has properties similar to those of auto-anti-Pr. Miltenberger Class III, IV, and VI erythrocytes have abnormal Ss-active sialoglycoproteins. Component beta appears altered in Miltenberger Classes I and II. These abnormalities may account for the unique serological properties of Class I, II, III, IV, and VI erythrocytes. Membranes from erythrocytes of type EnU K/Mk, Miltenberger Class V, and Ph contain abnormal sialogylcoproteins that may result from fusion of the genes that give rise to the Mn-and Ss-active sialoglycoproteins. If this is so, then the genes giving rise to the MN and Ss glycoproteins must be adjacent on the same chromosome.
mesh_terms: D000906:Antibodies; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000032:analysis*; D004912:Erythrocytes / Q000032:analysis* / Q000145:classification; D014644:Genetic Variation; D006801:Humans; D008951:MNSs Blood-Group System / Q000235:genetics; D010503:Periodic Acid-Schiff Reaction; D010641:Phenotype; D012795:Sialoglycoproteins / Q000097:blood* / Q000172:deficiency / Q000502:physiology
chemical_list: D000906:Antibodies; D008951:MNSs Blood-Group System; D012795:Sialoglycoproteins