Angiotensin II-generating enzymes

The renin--angiotensin system (RAS) is a system of enzymes and hormones that regulate blood pressure and electrolyte and fluid homeostasis in mammals. Angiotensin II (Ang-II) is one of the most important and well-known components of RAS. It is formed from the protein precursor angiotensinogen by the sequential actions of proteolytic enzymes. The classic pathway of Ang-II generation includes a reaction catalyzed by angiotensin-converting enzyme (ACE). However, there are alternative pathways for the generation of Ang-II. In this paper, possible routes of formation of Ang-II in the human body are reviewed. Various Ang-II-generating enzymes (tonin, cathepsin G, chymase, etc.) and their properties are considered. The classification of these enzymes is also considered.