Renin (REN)

Renin is a member of the aspartyl proteinase family produced largely in part by the juxtaglomerular cells in the kidney.Renin differs from the other members of this class by having a pH optimum near neutral pH region with native substrates instead of 2.0 to 3.4 This more neutral pH optimum allows it to be functional in the plasma.

Renin also has very high selectivity for substrate due to quite long peptide recognition on either side of the peptide bond undergoing cleavage. An octapeptide substrate was the minimum length to be cleaved by renin. Renin plays a crucial role in the regulation of blood pressure and salt balance through the cleavage of angiotensinogen, which is the only known physiological substrate of renin.