ACE2, also known as angiotensin-converting enzyme 2, is an integral membrane protein and a zinc metalloprotease of the ACE family that also includes somatic and germinal ACE. ACE2 cleaves angiotensin 1 to angiotensin 1-9 and angiotensin 2 to angiotensin 1-7 as a carboxypeptidase. It may be an important regulator of heart function and have a protective role in acute lung injury. Recombinant mouse ACE2, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.