Two ACEs in the pack

A study published in the online version of Circulation Research describes the discovery of ACE-related carboxypeptidase (ACE2) — the first human homologue of the protein ACE (angiotensin-converting enzyme). ACE2 was identified by scientists at Millennium Pharmaceuticals in Massachusetts, and is significant because it is restricted to the heart, kidneys and testes, potentially offering a specific target for drug treatment of hypertension and congestive heart failure.

ACE2 was identified during Millennium's ongoing search for novel genes related to heart failure, which involves sequencing thousands of tissue biopsies from its 'human heart failure ventricle' cDNA library. ACE and ACE2 have only 42% similarity; ACE2 is not inhibited by lisinopril or captopril, and produces an angiotensin peptide whose function is currently unknown. "The organ and cell-specific expression of ACE2 and its unique cleavage of key vasoactive peptides suggest an essential role for ACE2 in the local renin–angiotensin system of the heart and kidney," ...