Occurrence of nickel in carbon monoxide dehydrogenase from Clostridium pasteurianum and Clostridium thermoaceticum.

The carbon monoxide (CO) dehydrogenase activity band from Clostridium pasteurianum was shown to contain nickel by in situ activity staining of polyacrylamide gels. However, the majority of the nickel in cell extracts was found to electrophorese independently of CO dehydrogenase. Comparative analysis with Clostridium thermoaceticum demonstrated that, although the majority of nickel was accounted for in CO dehydrogenase in anaerobic extracts, the metal dissociated from the enzyme when inactivated by oxidation.