ACE2 contains a potential 17-amino acid N-terminal signal peptide and a putative 22-amino acid C-terminal membrane anchor. It is the only known mammalian homologue of the zinc-metallopeptidase angiotensin-converting enzyme (ACE), a critical regulator of the reninangiotensin system. ACE2 has a more restricted tissue distribution than ACE, being found predominantly in the heart, kidneys, and testes although low levels have been detected in a variety of tissues (PMID:15983030). The calculated molecular weight of ACE2 is 92kDa but it migrates to 120kDa due to N-glycosylation (PMID:16166094). It has 2 isoforms produced by alternative splicing. This antibody is specific to ACE2.