Capsular polysaccharide of Clostridium perfringens Hobbs 9

Several closely related capsular polysaccharides were isolated from a strain of Clostridium perfringens Hobbs 9 type A by extraction of encapsulated cells with cold 0.85% NaCl. The soluble polymers were precipitated with alcohol and purified by (NH4)2SO4 fractionation, enzymatic digestion with papain and ribonuclease, and chromatography on diethylaminoethyl-Sephadex A25. The polysaccharides were composed mainly of glucose, galactose, and galactosamine. The major fraction contained these constituents (representing 77% of the dry weight) in a molar ratio of 1:1.6:1.1. All of the fractions contained phosphate and peptide material that was not removed during purification. The polysaccharides were closely related but not identical as indicated by double-diffusion-in-gel experiments. Immunoelectrophoresis in agarose demonstrated that the polysaccharides had identical mobilities and that no resolution into additional fractions occurred. The immunological activity of all the purified polysaccharides was destroyed by periodate oxidation but was unaffected by protease.