[Structure-functional features of homologous domains of angiotensin-converting enzyme].

Somatic angiotensin-converting enzyme (ACE) consists of two homologous domains, each of them containing an active site. Differences in substrate specificities and affinity to inhibitors of the active sites of the two domains of bovine ACE are described. The ACE domains demonstrate different thermostability, and the reasons for this difference are analyzed. A structural model of the ACE domains is suggested, which allows us to reveal the structural subdomain important for the protein stability and localize the hydrophobic and the carbohydrate-binding sites.