title: Affinity purification and characterization of protease-susceptible antigen I of Streptococcus mutans.
abstract: An antigenic component (antigen I) of the cell surface of Streptococcus mutans has been purified from culture supernatants and shown to be immunologically identical to the protease-susceptible moiety of antigen I/II. Ion-exchange and gel filtration chromatography failed to yield a physicochemically homogeneous product. Immunoasbsorbent chromatography on single and tandem columns containing immobilized antibodies to antigens I/II and II yielded identical products which were homogeneous in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and which when injected into rabbits induced monospecific antisera to antigen I. This antigen consisted of approximately 70% protein. Its molecular weight was estimated as 150,000, and the isoelectric point was estimated to be 5.1. Immunofluorescence microscopy using monospecific antiserum to antigen I showed that a similar antigen was present on cells of S. mutans serotypes a, c, d, e, f, and g, but not b.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000302:isolation & purification*; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D007106:Immune Sera / Q000494:pharmacology; D007164:Immunosorbents / Q000494:pharmacology; D009055:Mouth / Q000382:microbiology; D010447:Peptide Hydrolases / Q000494:pharmacology*; D011817:Rabbits; D013295:Streptococcus mutans / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D007106:Immune Sera; D007164:Immunosorbents; D010447:Peptide Hydrolases