Angiotensinogen (AGT) is part of the renin-angiotensin system (RAS), which plays an important role in blood pressure regulation, renal hemodynamics, as well as fluid and electrolyte homeostasis. It is also involved in normal and abnormal growth processes. The growth promoting actions of angiotensin have been shown in a variety of cells and tissues. This subgroup represents clade A8 of the serpin superfamily. In general, SERine Proteinase INhibitors (serpins) exhibit conformational polymorphism shifting from native to cleaved, latent, delta, or polymorphic forms. Many serpins, such as antitrypsin and antichymotrypsin, function as serine protease inhibitors which regulate blood coagulation cascades. Non-inhibitory serpins perform many diverse functions such as chaperoning proteins or transporting hormones. Serpins are of medical interest because mutants have been associated with blood clotting disorders, emphysema, cirrhosis, and dementia. A classification based on evolutionary relatedness has resulted in the assignment of serpins to 16 clades designated A-P along with some orphans.
Comment:depending on the conformational state, the RC loop is surface accessible in the active form or buried and inserted as the central beta strand in the inactive form.
Structure:2WXZ_A: Rattus norvegicus angiotensinogen RCL, only part is visible, in open conformation
Jiyao W et al.(2023). "The conserved domain database in 2023.",