Purification and characterization of a saliva-interacting cell-wall protein from Streptococcus mutans serotype f by using monoclonal-antibody immunoaffinity chromatography.
A rat monoclonal antibody, LO SM2, of the immunoglobulin M class, specific for a saliva receptor (SR) from Streptococcus mutans serotype f, was able to precipitate the SR from crude cell-wall-associated antigens (WEA) of this bacteria in presence of a detergent mixture. We have then used the technique of monoclonal-antibody immunoaffinity chromatography to purify the S. mutans SR. Pure SR was obtained from a crude WEA fraction with a single chromatographic step. The active SR could be eluted from the column in a highly purified form with 0.2 M-glycine/HC1, pH 2.8. The final yield was about 32% in terms of binding activity. Characterization of the SR by crossed immunoelectrophoresis, sodium dodecyl sulphate- or 4-30%-native-gradient-polyacrylamide-gel electrophoresis showed that the receptor is a single polypeptide chain of Mr approx. 74000. Native or denaturated forms of the SR adsorbed on to a solid support, such as nitrocellulose, are recognized by monoclonal antibody LO SM2, and both forms are still able to bind the ligand, saliva.
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins / Q000302:isolation & purification*; D002473:Cell Wall / Q000032:analysis; D011232:Chemical Precipitation; D002846:Chromatography, Affinity / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000302:isolation & purification; D007123:Immunoelectrophoresis, Two-Dimensional; D007163:Immunosorbent Techniques; D008854:Microscopy, Electron; D012463:Saliva; D013295:Streptococcus mutans / Q000032:analysis*
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D006023:Glycoproteins; C045564:saliva-interacting cell wall protein, Streptococcus