Clostridium oedematiens η-antigen, an enzyme decomposing tropomyosin

Abstract

Certain crude toxins of C. oedematiens decompose tropomyosin and myosin. The decomposition of tropomyosin takes place in 3 stages characterized by (1) rapid decrease in viscosity; (2) production of particles soluble in trichloroacetic acid but not diffusible through cellophane; (3) slow production of diffusible particles. The viscosity-reducing action is due to a sulfhydryl-activated enzyme, which was named a tropomyosinase, whose action is inhibited by homologous antisera. The enzyme does not attack collagen, nor hemolyze the red blood cells of sheep and horses. It is activated by cysteine, glutathione and thiolacetate, but not by thiosulfate. It is not inhibited by soy-bean trypsin inhibitor. By neutralization tests with selective antisera, this tropomyosinase was identified as a specific antigen which was designated, in accordance with the nomenclature of Oakley et al. (1947), as C. oedematiens n-antigen. It was found in crude toxins of C. oedematiens type B and C. haemolyticum, but not in C. oedematiens type A nor in C. welchii, C. septicum or Corynebacterium diphtheriae toxins.