Inhibition of angiotensin-converting enzyme by selenoneine

Selenoneine is a selenium-containing compound that exhibits strong radical-scavenging activity. Here we present a novel function of selenium in which selenoneine exhibits inhibitory activity against angiotensin-converting enzyme (ACE). ACE activity was strongly inhibited by selenoneine as compared to a typical peptide that decreases blood pressure in vitro. Kinetics analysis suggested that selenoneine inhibits ACE by competitive inhibition via the binding of selenoneine to zinc in the active center of ACE.