Chromatographic and kinetic properties of acid- and pepsin-activated inactive renin from human amniotic fluid

The Chromatographic and kinetic properties of acid- and pepsin-activated inactive renin from human amniotic fluid were determined. Acid-activated inactive renin, like inactive renin, was found to be bound to an Affi-Gel Blue affinity column. Pepsin-activated inactive renin, on the other hand, did not bind to such a column. The K_m values of endogenous active renin, acid-activated inactive renin, and pepsin-activated inactive renin with bovine substrate were 0.11, 0.12 and 0.05 μM respectively. With hog substrate, the K_m values were 0.16,0.19 and 0.10 μM respectively. These results suggest that there is a difference between the active form of renin obtained from acid activation of inactive renin and the active renin obtained after pepsin treatment.