4.4.1.23 Co2+ the inactive and Zn-deficient form of enzyme is activated by addition of ZnCl2 or CoCl2 393831 4.4.1.23 Zn Zn plays a key role in activating an organic thiol substrate for nucleophilic attack on an alkyl-donating substrate, removal of Zn results in loss of catalytic activity, the inactive and Zn-deficient form of enzyme is activated by addition of ZnCl2 or CoCl2. Thermodynamic characterization of the interaction of CoM with an enzyme-bound Zn center 393831 4.4.1.23 Zn2+ the inactive and Zn-deficient form of enzyme is activated by addition of ZnCl2 or CoCl2 393831