The formation and properties of cobalt (III) carbonic anhydrase

Cobalt (III) bovine carbonic anhydrase B was prepared by the oxidation of the corresponding cobalt (II) enzyme with hydrogen peroxide. The cobalt (III) enzyme was found to be inactive towards the hydration of carbon dioxide and the hydrolysis of p-nitrophenyl acetate. The oxidation reaction is considerably slowed down in the presence of various anion and sulfonamide inhibitors of carbonic anhydrase. The oxidation products have characteristic absorption spectra indicating direct binding of the anion inhibitors to the metal ion in the cobalt (III) carbonic anhydrase.