title: Specificity of anti-Mg antibody--a study with synthetic peptides and glycopeptides.
abstract: The specificity of a human anti-Mg antibody has been evaluated by agglutination-inhibition assays using several peptides and glycopeptides structurally related to the N-terminal end of glycophorin A, which were obtained by chemical synthesis. We have shown that the anti-Mg antibody is strongly inhibited by pentapeptides containing a leucine residue at their N-terminal end. Glycosylations of these peptides at positions 2, 3 and 4 by N-acetylgalactosamine and/or galactose-beta 1-3-N-acetylgalactosamine units abolish the biological activity, as well as the masking of the leucine residue by addition of N-acetylglycine. The results demonstrate also that the presence of an asparagine residue at position 4 of the pentapeptides (or glycopeptides) is not a requirement for Mg specificity and suggest that the antibody recognizes primarily a nonglycosylated peptide structure with an N-terminal leucine residue.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D006020:Glycopeptides / Q000138:chemical synthesis / Q000276:immunology*; D006021:Glycophorins / Q000276:immunology*; D006031:Glycosylation; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D008951:MNSs Blood-Group System / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology*; D011817:Rabbits; D012795:Sialoglycoproteins / Q000276:immunology*
chemical_list: D000906:Antibodies; D000939:Epitopes; D006020:Glycopeptides; D006021:Glycophorins; D008951:MNSs Blood-Group System; D010446:Peptide Fragments; D012795:Sialoglycoproteins