Angiotensin-converting enzyme is a zinc metallopeptidase that plays roles in blood pressure regulation and fertility. The catalytic activities of angiotensin converting enzymes include the production of the potent vasopressor angiotensin II from angiotensin I, and the inactivation of the vasodilatory peptide bradykinin. Zace1 is a new form of human zinc metallopeptidase, which includes one zinc-dependent catalytic domain containing the motif “HEXXH” and one downstream “EX(I/V)X(D/S)” motif.