title: Type-specific immunogenicity of a chemically synthesized peptide fragment of type 5 streptococcal M protein.
abstract: We determined the antigenic specificity and protective immunogenicity of two chemically synthesized peptides of type 5 streptococcal M protein. The synthetic peptides, designated S-M5(1-20) and S-M5(20-40), represent the amino-terminal amino acid sequence of the native pepsin-extracted M5 molecule, which is known to contain at least one heart cross-reactive epitope. Initial studies showed that neither of the synthetic peptides was able to bind purified heart-reactive M5 antibodies. In addition, S-M5(1-20), but not S-M5(20-40), contained type-specific antigenic determinants as measured by enzyme-linked immunosorbent inhibition assays. When covalently linked to tetanus toxoid, S-M5(1-20), but not S-M5(20-40), evoked significant levels of type-specific, opsonic (and presumably protective) antibodies in rabbits without evoking heart cross-reactive antibodies.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins; D000939:Epitopes / Q000276:immunology; D006801:Humans; D009206:Myocardium / Q000276:immunology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology*; D011817:Rabbits / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology
chemical_list: D000906:Antibodies; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D000939:Epitopes; D010446:Peptide Fragments; D013745:Tetanus Toxoid; C014689:streptococcal M protein