2 PEAKS IN PH-DEPENDENCE OF RENIN-ANGIOTENSINOGEN REACTION

The pH dependence of the reaction of purified recombinant human renin with purified recombinant sheep angiotensinogen was not a typical bell -shape but had two peaks, pH 6.4 and 8.9, The pH dependence of the rea ction of human renin with human, hog, and rat angiotensinogens partial ly purified from plasma had a peak with a shoulder containing two peak s close together. These findings indicate that the reaction of renin w ith angiotensinogen involves at least two amino acid residues other th an the two aspartic acid residues known to be involved and occurs at a cidic pH and basic pH by two different pairs of these amino acid resid ues.