title: Structural analysis of the Ss sialoglycoprotein specific for Henshaw blood group from human erythrocyte membranes.
abstract: The N-terminal structures of the MN and Ss erythrocyte membrane sialoglycoproteins (glycophorins A, B) from two Henshaw (He) blood-group heterozygotes were determined by manual sequencing of tryptic glycopeptides and various secondary fragments. No structural alteration of the MN glycoprotein could be detected. The He-specific portion of the Ss glycoprotein was found to exhibit the N-terminal sequence Trp-Ser+-Thr+-Ser+-Gly-(+ = glycosylation). Thus it differs at three positions from its normal counterpart which possesses 'N' activity and exhibits the N-terminal structure Leu-Ser+-Thr+-Thr+-Glu-. Analysis of the Ss glycoprotein from 15 He-negative erythrocyte samples did not reveal any of the three He-specific structural alterations. The presence of a glycine residue at the fifth position of the blood-group-M-active MN glycoprotein as well as in the He-specific Ss glycoprotein provides an explanation for the occurrence of antisera (anti-Me) reacting with the M and He antigens.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D004910:Erythrocyte Membrane / Q000276:immunology*; D006021:Glycophorins / Q000097:blood*; D006579:Heterozygote; D006801:Humans; D007519:Isoantigens / Q000302:isolation & purification; D008951:MNSs Blood-Group System / Q000276:immunology*; D010446:Peptide Fragments / Q000302:isolation & purification; D012795:Sialoglycoproteins / Q000097:blood*
chemical_list: D000596:Amino Acids; D006021:Glycophorins; D007519:Isoantigens; D008951:MNSs Blood-Group System; D010446:Peptide Fragments; D012795:Sialoglycoproteins