Human Renin is a member of the aspartyl proteinase family produced largely in part by the juxtaglomerular cells in the kidney. 1 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. 2 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. Renin releases the decapeptide angiotensin I, which in turn is further converted to vasoactive hormone angiotensin II by angiotensin converting enzyme (ACE). Renin is produced as prorenin with 43 pro residues at the N-terminal of mature renin. The inactive prorenin becomes activated proteolytically by trypsin, cathepsin B, or other proteinases. Recombinant protein corresponding to Leu24-Arg406 from human Renin, expressed with a C-terminal 10-His tag in a murine myeloma cell line, NS0. Uniprot/Swiss Accession: P00797 Molecular Mass: TrhREN has the N-terminal sequence of L24 PTDTTTFKR, which corresponds to the beginning of the pro form. The 393 amino acid residue rhREN predicts a molecular mass of approximately 44kD, and migrates as 44 and 51kD doublets by SDS-PAGE under reducing conditions. Activity: Measured by its ability to cleave a fluorogenic peptide substrate, Arg-Glu(EDANS)-Ile-His-Pro-Phe-His-Pro-Phe-His-Leu-Val-Ile-His-Thr-Lys(dabcyl)-Arg. The specific activity, measured with 20uM substrate and 200ng rhREN in 100ul of the assay buffer at RT, is >20pmoles/min/ug. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
