Serpin A8 (serine?proteinase?inhibitor-clade?A #8; also angiotensinogen/ANGT) is a secreted, 52-62 kDa glycoprotein member of the clade F-subfamily, serpin superfamily of protease inhibitors.? It is expressed by neurons and hepatocytes, and undergoes extracellular cleavage by renin to create a ten amino acid (aa) peptide termed Ang/angiotensin I. ?This inactive peptide is further cleaved by ACE on the endothelial cell membrane to create bioactive Ang II.? Ang II induces vascoconstriction and aldosterone release.? Mature human Serpin A8 is 452 aa in length (aa 34-485).? It contains Ang I (aa 34-43) that is cleaved to create Ang II (aa 34-41).? Serpin A8 may circulate in a 200 kDa complex with major basic protein (MBP), or as part of a larger 300 kDa complex with MBP and complement C3dg. ?Over aa 34-485, human Serpin A8 shares 61% aa identity with mouse Serpin A8.

AGT; alpha-1 antiproteinase, antitrypsin; Angiotensin II; angiotensinogen (serpin peptidase inhibitor, clade A, member 8); Angiotensinogen; ANHU; Aogen; FLJ92595; FLJ97926; PAT; pre-angiotensinogen; serine (or cysteine) proteinase inhibitor; Serpin A8; SERPINA8angiotensin I