Angiotensin-converting enzyme (ACE, peptidyl dipeptidase A) is well known as a key enzyme involved in regulation of blood pressure. Regulation of blood pressure is the main but not the only ACE function. This enzyme is also involved in the regulation of a range of other physiological processes including control of cells proliferation. Particular role of the enzymein a given process is determined by its localization and its action on regulatory peptides. Structural peculiarities of angiotensin-converting enzyme and its gene polymorphism related to its physiological function are discussed. ACE molecule consists of two large homologous domains (N- and C-domains), differingin their catalytical properties. These differences are suggested to be physiologicaly impotant. Endogenous substrates specific for each of these domains and natural active single-domain ACE forms were revealed. An association between the ACE gene polymorphism and plasma ACE levels, as well as with an increased risk of various cardiovascular and renal diseases was observed.
