[Immunochemical analysis of the cytoplasmic fraction of group A streptococci]

The immunochemical and chromatographic analysis of a cytoplasmic preparation, obtained from group A (type 5) streptococcus by the mechanical disintegration of microbial cells with subsequent centrifugation, was carried out. The gel filtration of cytoplasm on Sephadex G-100 allowed to observe the distinct separation of the material into 2 fraction. The serological study of sera from patients with rheumatism and chronic tonsillitis, as well as hyperimmune rabbit sera, indicated that the antigenic activity of the cytoplasmic preparations was almost completely determined by the high-molecular fraction. The rechromatography of this fraction on a column packed wtih DEAE cellulose resulted in the isolation of 2 immunologically active subfractions.