Capsular polysaccharide of Clostridium perfringens Hobbs 10

Abstract

A capsular polysaccharide was isolated from a strain of C. perfringens Hobbs 10 type A by cold water extraction of whole, heavily encapsulated cells. The water soluble polymer was isolated by alcohol precipitation and purified by treatment with chloroform butanol, cetytrimethylammonium bromide, and column gel permeation chromatography by using Bio Gel A 5m agarose. The formation of a single precipitin line, when the isolated polysaccharide was reacted with its homologous antisera by double diffusion in gel, was considered a criterion of immunochemical purity. The purified polymer appeared as a single peak when eluted from diethylaminoethyl Sephadex with a linear gradient of NaCl. The polysaccharide was composed of glucose, galactose, galactosamine, and iduronic acid in a molar ratio of 4.1:5.1.7:1, respectively. These constituents accounted for 83% of the dry weight. The polysaccharide appeared to have a molecular weight of 40,000 and exhibited aggregation up to 120,000. A trace of peptide material could not be removed during purification.