A2294-48S

Sheep Anti-Angiotensinogen (Serpin A8, AGT, SERPINA8)

Serpin A8 is a secreted, 52-62kD 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 aa peptide termed Ang/angiotensin I. This inactive peptide is further cleaved by ACE on the endothelial cell membrane to create bioactive Ang II and III. Ang II induces vascoconstriction and aldosterone release by acting on AT1 receptors, while Ang III drives aldosterone release. Ang I can be further processed by MME to generate Ang, a peptide that binds MAS1 on platelets, and promotes the release of NO, an antithrombotic agent. Mature mouse angiotensinogen is 453aa in length aa25-477. It contains Ang I aa25-34 that is cleaved to create Ang II aa25-32, Ang III aa26-32 and Ang I aa25-31. Serpin A8/Angiotensinogen may circulate in a 200kD complex with major basic protein (MBP), or as part of a larger 300kD complex with MBP and complement C3dg. There is an alternative start site 5aa upstream of the standard site. Over aa25-477, mouse serpin A8 shares 86% and 61% aa identity with rat and human serpin A8.