BIOCHEMICAL AND IMMUNOCHEMICAL ANALYSIS OF CELL-WALL PROTEIN-COMPONENTS ISOLATED FROM GROUP-A STREPTOCOCCI BY A SPARING CHEMICAL METHOD

To study the protein components of the cell wall of group A streptococ ci, type M 29, a special preparative method was developed (extraction with 1 M hydroxylamine solution, pH 6.0, and subsequent purification). Altogether six protein fractions were obtained. The isolated proteins were found to be a heterogeneous group of molecules, consisting of 25 -40 individual proteins with molecular weights ranging between 13 and 94 kD. The study of the protein fractions thus obtained in the immunod iffusion test with rabbit antiserum to the initial protein preparation revealed that these proteins contained type-specific components, 3-6 type-nonspecific protein antigens common with protein antigens of M 1 and M 12, as well as one protein antigen common with type M 1. Fc rece ptor was shown to be absent. The detected type-nonspecific protein ant igens were partially separated by ion-exchange chromatography and some of them could be purified from the admixtures of nucleic acids and gr oup-specifci polysaccharide.