Angiotensin-converting enzyme 2–spike protein interaction

The angiotensin-converting enzyme 2 (ACE2)–spike protein interaction refers to the binding of the spike (S) glycoprotein from coronaviruses, notably SARS-CoV and SARS-CoV-2, to the ACE2 receptor on host cells. This interaction is critical for viral entry into human cells and underpins the pathogenesis of COVID-19. ACE2 acts as a carboxypeptidase in the renin–angiotensin system (RAS), converting angiotensin II into angiotensin-(1–7), thereby counteracting vasoconstriction and lowering blood pressure. Engagement by coronavirus S proteins can lead to downregulation or shedding of surface ACE2—potentially contributing to tissue injury through dysregulated angiotensin II signaling during infection.