title: Structures of Miltenberger class I and II specific major human erythrocyte membrane sialoglycoproteins.
abstract: The N-terminal structures of the Miltenberger (Mi-) blood group class I and II specific human MN erythrocyte membrane sialoglycoproteins were determined by manual sequencing of tryptic glycopeptides and various secondary fragments. The Mi-I and Mi-II active glycoproteins were found to exhibit a threonine leads to methionine and threonine leads to lysine exchange, respectively, at position 28 which prevents N-glycosylation of asparagine 26. Due to the absence of the N-glycosidic oligosaccharide chain, the monomeric form of the Mi-I and Mi-II specific glycoproteins possesses a slightly increased sodium dodecyl sulfate/polyacrylamide gel electrophoretic mobility, in comparison to its normal counterpart. Serological studies suggest that antibodies, specific for Mi-I or Mi-II red cells, react with the structurally altered region of the MN glycoprotein.
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification; D001798:Blood Proteins / Q000145:classification; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000032:analysis*; D006801:Humans; D008951:MNSs Blood-Group System; D010446:Peptide Fragments / Q000302:isolation & purification; D012795:Sialoglycoproteins / Q000097:blood* / Q000145:classification
chemical_list: D000596:Amino Acids; D001798:Blood Proteins; D008951:MNSs Blood-Group System; D010446:Peptide Fragments; D012795:Sialoglycoproteins