Angiotensin Converting Enzyme (ACE) is a zinc metallopeptidase enzyme that catalyzes the conversion of angiotensin I to angiotensin II, a key step in the renin-angiotensin-aldosterone system (RAAS) regulating blood pressure and fluid balance. This purified enzyme preparation is used in biochemical research, enzyme activity assays, inhibitor screening, and studies of cardiovascular physiology. It exhibits high specific activity (≥2.0 units/mg protein) and is supplied as an off-white to beige powder, confirmed by infrared spectroscopy to match the expected structure. Applications include in vitro studies of RAAS pathways, development of antihypertensive drugs, and investigation of renal and cardiac functions.