title: Immunochemistry of the streptococcal group R cell wall polysaccharide antigen.
abstract: The group R streptococcal group antigen has been shown to be a polysaccharide located at the surface of the cell wall of the organism. The antigen was extracted from cell walls in 0.05 n HCl or 5% trichloracetic acid at 100 C, from whole cells at room temperature in 0.85% NaCl or 0.1 m acetate (pH 5.0), and by sonic oscillation. The antigen is largely destroyed when extracted from whole cells in 0.05 n HCl at 100 C. Acetate is recommended for routine extraction. The antigen extracted by sonic treatment was separated into six immunologically active fractions on diethylaminoethyl-Sephadex. The fractions were found to possess a common antigen which exhibited similar properties on immunodiffusion and immunoelectrophoresis. The purified antigen did not react with any other streptococcal group antisera. Adsorption of group R serum with the antigen removed all antibodies against whole cell antigen extracts of R cells. Chemical and enzymatic analysis of three fractions showed that the antigen was composed of d-glucose, d-galactose, rhamnose, and glucosamine. No significant quantities of phosphorus, glycerol, ribitol, or muramic acid were present. Significant inhibition of the quantitative precipitin determination by d-galactose and stachyose indicated that galactose in terminal alpha linkage was the immunodominant hexose in the antigen. d-Glucose and d-glucosamine possessed a partial inhibitory activity. N-acetyl-d-glucosamine and l-rhamnose did not produce significant inhibition. The results indicate that the R antigen is an immunologically specific structure which serves as a reliable means of identification of these streptococci as a serological group.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D002473:Cell Wall / Q000276:immunology*; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D005690:Galactose / Q000032:analysis; D005944:Glucosamine / Q000032:analysis; D005947:Glucose / Q000032:analysis; D006868:Hydrolysis; D007106:Immune Sera; D007120:Immunochemistry; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D011233:Precipitin Tests; D011817:Rabbits / Q000276:immunology; D012210:Rhamnose / Q000032:analysis; D013291:Streptococcus / Q000254:growth & development / Q000276:immunology*; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D000942:Antigens, Bacterial; D007106:Immune Sera; D011135:Polysaccharides, Bacterial; D005947:Glucose; D005944:Glucosamine; D012210:Rhamnose; D005690:Galactose