title: Protein antigens of Streptococcus mutans: purification and properties of a double antigen and its protease-resistant component.
abstract: A surface protein antigen of Streptococcus mutans having two sets of antigenic determinants (antigens I and II) was purified by column chromatography from culture supernatants of S. mutans serotype c. The protease-resistant component, antigen II, was purified from pronase-digested antigen I/II. The antigens were analyzed chemically and immunologically, and their physicochemical properties were investigated. Antigen I/II consisted of more than 80% protein, and its peptide chain molecular weight was estimated to be 185,000. Antigen II consisted of approximately 60% protein, with a peptide chain molecular weight of 48,000. Antisera to antigens I/II and II were raised in rabbits and used to investigate the presence of the antigens in cells of other streptococci. This indicated that not only serotype c but also serotypes e and f possessed antigen I and II determinants, whereas serotypes a, d, and g possessed a determinant related to antigen I but not one related to antigen II.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D007106:Immune Sera; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000032:analysis; D011817:Rabbits; D012703:Serotyping; D013295:Streptococcus mutans / Q000276:immunology*
chemical_list: D000596:Amino Acids; D000942:Antigens, Bacterial; D007106:Immune Sera; D010447:Peptide Hydrolases