title: Purification and characterization of Clostridium perfringens iota toxin: dependence on two nonlinked proteins for biological activity.
abstract: Clostridium perfringens type E iota toxin, a dermonecrotic and lethal binary toxin, was purified to homogeneity. Each protein component of the toxin, iota a (ia) or iota b (ib), appeared as a single band by gradient or sodium dodecyl sulfate-polyacrylamide gel electrophoresis and yielded a single immunoprecipitin arc by crossed immunoelectrophoresis with homologous antiserum. Individually, ia (Mr 47,500) or ib (Mr 71,500) had little biological activity. However, when combined in equimolar amounts, there was a 64-fold increase in the guinea pig dermonecrotic titer. The biological activity of ia was heat stable (85 degrees C for 15 min), whereas ib was inactivated at 55 degrees C. Our results demonstrated that C. perfringens iota toxin required two different, nonlinked protein components for biological activity.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification; D001427:Bacterial Toxins / Q000302:isolation & purification* / Q000633:toxicity; D001681:Biological Assay; D003016:Clostridium perfringens / Q000032:analysis / Q000472:pathogenicity*; D006168:Guinea Pigs; D006358:Hot Temperature; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D046911:Macromolecular Substances