REACTIONS OF STAPHYLOCOCCAL ANTIGENS WITH NORMAL SERA, γG‐GLOBULINS, AND γG‐GLOBULIN FRAGMENTS OF VARIOUS SPECIES ORIGIN

Abstract

Normal sera from 14 species have been tested for activity against crude protein A. Sera from 6 species produced the protein A line in agar gel, but none of the sera gave the protein B line. Sera from 7 species, including 3 of those precipitating protein A, agglutinated tanned sheep erythrocytes sensitized with crude protein A. With a few individual exceptions, all the sera tested agglutinated Cowan I bacteria. Isolated γG‐globulins showed activities corresponding to their respective sera. The active part of the γG‐globulins in the precipitation reaction with protein A was located to Fc whereas Fab was the active part both in indirect haemagglutination and bacterial agglutination. Rabbit antiserum to Cowan I bacteria and guinea pig antiserum to crude protein A gave results similar to those of normal sera with regard to precipitation of protein A, indirect haemagglutination and bacterial agglutination. In addition both sera precipitated protein B, this ability being located to the Fab region of the γG‐globulins.