Angiotensin converting enzyme 2 (ACE-2), also known as ACEH (ACE homolog), is an integral membrane protein and a zinc metalloprotease of the ACE family. The predicted human ACE-2 protein sequence consists of 805 amino acids, including a N-terminal signal peptide, a single catalytic domain, a C-terminal membrane anchor, and a short cytoplasmic tail. ACE-2 cleaves angiotensins I and II as a carboxypeptidase.
ACE-2 also serves as the receptor for the SARS-CoV and SARS-CoV-2 viruses. Binding of the S1 domain of the SARS Coronavirus Spike protein to ACE-2 initiates viral entry into the host cell. Recently, this interaction between SARS-CoV-2 and ACE-2 has become an area of intense therapeutic interest to develop treatments against COVID-19.