Effect of some Chemical Agents on Renin Activity in vitro

Abstract

The effect of different chemical reagents on renin has been investigated. After treatment of hog renin with acetic anhydride, 1-fluoro-2,4-dinitrobenzene, diazobenzene sulfonic acid and phenyl isocyanate, the enzymic activity assayed both biologically and chemically was depressed, whereas no effect occurred after treatment with diisopropyl fluorophosphate, p-chloromercuribenzoate and after dialysis against EDTA. Human renin, too, is inactivated by acetylation, diazo coupling and dinitrobenzoylation. The results indicate that one or several amino groups of the renin molecule are essential for enzymic activity.

Nitrophenyl Esterase Activity in Renin Preparations

“…The esterase activity was stable for several days at 4 °C, while most of the renin activity disappeared within a day unless the fractions were frozen. Another way of distinguishing between the esterase and renin activities is by testing the effects of inhibitors on the two reactions Reinharz et al [7] have investigated the effects of several common protein reagents on renin and have assayed the treated renin by both bioassay and chemical assay. Table III shows our results and those of Reinharz et al [7] for comparison.…”

“…All experiments were carried out using 0.7 mg/ml stock solution of the commercial renin in 0.05 mol/1 phosphate at pH 5.6 according to the pro cedure of Reinharz et al [7] with the exception that we used PMSF instead of DFP [8].…”

Purification of renin and prorenin.

“…It did not seem to belong to a known type of proteases since it was refractory to known types of group-specific protease inhibitors such as diisopropyl fluorophosphate (for serine protease), 1213 metal chelators (for metalloenzymes), 12 or the thiol-specific reagents p-chloromercuribenzoate (for cysteine proteases). 13 It looked as if it had very narrow substrate specificity limited to one specific leucyl peptide bond present only in the angiotensinogen molecule. Such unusual properties made renin a highly tantalizing subject for a biochemist.…”

“…/>-chloromercuri-benzoate, 13 or EDTA, 12 precluded the possibility of renin being serine-, cysteine-, or metallo-protease. However, its affinity to pepstatin (albeit weak) 25 - 29 suggested the possibility that it belongs to the acid (aspartyl) protease family.…”

Dithiothreitol Augments Renin Activity by an Action on Renin Substrate

“…Furthermore, treatment of renin with dithiothreitol (DTT, Cleland's reagent) did not influence its pressor potency, as determined by direct assay in the rat (1). Hog renin was also reported to be resistant to treatment with p-chloromercuribenzoate (PCMB) and iodoacetamide (2). Human renin acting on hog substrate has similar properties since it was not inhibited by iodoacetamide, merthiolate, or phenylmercuriacetate (3).…”