Renin (angiotensinogenase) which hydrolyzes angiotensinogen is a component of the renin-angiotensin system (RAS) that regulates vasoconstriction and blood pressure. Angiotensinogen 1-14 (DRVYIHPFHLLVYS) may be used as a substrate for renin. A variety of renin substrates may be built around the minimal sequence His-Pro-Phe-His-Leu-Leu-Val-Tyr (HPFHLLVY).