Nature of a red cell sensitizing substance from streptococci.

Jackson, Robert W. (Purdue University, Lafayette, Ind.), and Merwin Moskowitz. Nature of a red cell sensitizing substance from streptococci. J. Bacteriol. 91:2205-2209. 1966.-A method for purifying a streptococcal antigen which sensitizes red cells to agglutination by antiserum is described. The antigen, when purified by this method, is almost exclusively composed of glycerophosphate and d-alanine. The ratio of alanine to glycerophosphate varies from 1:5 to 1:3. The glycerophosphate is polymerized and is thus a teichoic acid. The polyglycerophosphate appears to be the antigenic determinant for agglutination. d-Alanine is readily removed by mild base and appears to be necessary for the attachment of the teichoic acid to red cells. Quantitative removal of alanine does not affect the ability of the polymer to absorb antibody from serum.