Urease Activity as Influenced by Oxidation and Reduction

Abstract

The activity of crystalline urease was suppressed by oxidation, e.g., with iodine or with air in the presence of cupric ions. These reactions could be controlled so that the inactivation was reversed by treatment with such substances as H2S, HS-glutathione, thioglycollate, cysteine (not cystine). Certain metal derivatives, e.g., C6H5HgOH, C6H5CH2HgCl, CU2O, which are known to form with sulphydryl compounds characteristic derivatives (mercaptides) "extinguished" urease activity; the latter was completely regenerated by the action of HaS or HCN. Some of the phenomena in this field might perhaps be ascribed, not to changes in a supplementary activator, but to oxidation of and regeneration of the sulphydryl groups of the enzyme, itself.