Kinetic studies of rat renin and tonin on purified rat angiotensinogen
- 1 February 1984
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Biochemistry and Cell Biology
- Vol. 62 (2-3) , 137-142
- https://doi.org/10.1139/o84-020
Abstract
Kinetic studies of highly purified rat renin and rat tonin on completely purified angiotensinogen and angiotensin-tetradecapeptide synthetic renin substrate were performed. The Michaelis–Menten constant (Km) for renin, determined at the optimum pH, was 2.8 ± 0.03 μM for angiotensinogen and 28.8 ± 2.69 μM for angiotensin-tetradecapeptide renin substrate. The Km of purified rat tonin was determined as 0.66 ± 0.18 μM for angiotensinogen and 2.33 ± 0.42 μM for angiotensin tetradecapeptide. In comparison with renin, tonin shows higher affinity with respect to angiotensinogen, but the turnover number of natural substrate molecules observed with renin (0.87 s−1) is more than 3700 times higher than that of tonin (2.3 × 10−4 s−1). Renin shows higher affinity to angiotensin tetradecapeptide than tonin, but similar turnover numbers of 2.8 and 10.0 s−1 are observed for hydrolysis of angiotensin tetradecapeptide by renin and tonin, respectively.This publication has 0 references indexed in Scilit: