Abstract
Carbamyl-adenesine diphesphate (ADP) phosphoforase, an enzyme which eatalysos the synthosis and broakdown of oarbamyl phosphate (CAP), has beon purified 43-fold and obtained free of carbamyl phosphate phosphatase activity. ADP, but not. adenosine mOllophosphate, has been shown to be a sllbsLrate for the enzyme. Magnesium or manganous ions are requirod for activity. Inhibition by heavy metal cations and p-chloromorcuribenzoato indicate that, a sulpbydryl group is involved in catalysis.