Two molecular forms of Clostridium perfringens alpha-toxin associated with lethal, hemolytic and enzymatic activities.

The ƒ¿-toxin of Clostridium perfringens (werchii) contains both the lethal and hemolytic activities. It was identified as phospholipaseC (EC 3.1.4.3) catalyzing the hydrolysis of lecithin to a diglyceride and phosphorylcholine (Macfarlane and Knight, 1941). Pastan et al. (1968) separated the phospholipaseC of C. perfringens into two fractions, one preferentially hydrolyzing sphingomyelin to ceramide and phosphorylcholine and the other lecithin. By isoelectric focusing, Bernheimer et al. (1968) also resolved the phospholipaseC into two molecular forms having enzymatic (eggyolk reaction) and hemolytic activities. In these reports, however, no attempts were made to correlate phospholipaseC activity with the lethal toxicity. It seemed justified, therefore, to clarify whether the ƒ¿-toxin is separable into two fractions with respect to the lethal toxicity and, if so, whether both fractions are associated with the hemolytic and enzymatic activities. In this communication we report a complete separation by isoelectric focusing of the lethal toxicity of the ƒ¿-toxin into two parts, ƒ¿1and ƒ¿2-toxins, having hemolytic, lecithin-hydrolyzing and sphingomyelin-hydrolyzing activities as well as the antitoxin-binding power. Crude ƒ¿-toxin was prepared from a culture filtrate of C. perfringens PB6K