title: Effect of zinc and calcium ions on the production of alpha-toxin and proteases by Clostridium perfringens.
abstract: Clostridium perfringens produced at least three distinct proteases in a synthetic medium containing calcium. Two of them, thiol and ethylenediaminetetraacetic acid disodium salt-sensitive proteases, appeared at an early stage of growth, but the other one, perhaps being identical to the one produced in a calcium-deficient medium, appeared at a late stage. The production of these proteases depended on Ca2+ but not on Zn2+ in the medium. Alpha-toxin, perhaps being a zinc-containing metalloenzyme, was rather resistant to the proteases, but toxin, produced in a zinc-deficient medium or deprived of zinc with ethylenediaminetetraacetic acid disodium salt, was very sensitive. By adding Zn2+, the toxin lacking zinc may have been converted to the zinc-containing metalloprotein that is resistant to proteases. This may explain why alpha-toxin activity increased progressively in a zinc-containing medium in spite of simultaneous production of potent proteases and why it disappeared rapidly in a zinc-deficient medium.
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology*; D002413:Cations, Divalent; D003016:Clostridium perfringens / Q000201:enzymology / Q000378:metabolism*; D008667:Metalloproteins / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D011485:Protein Binding; D015032:Zinc / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D001427:Bacterial Toxins; D002413:Cations, Divalent; D008667:Metalloproteins; D010447:Peptide Hydrolases; D015032:Zinc; D002118:Calcium