Steady-state kinetic study of action of ribonuclease A, involving a conformational change between 30 and 40.degree.C

Abstract

The steady-state kinetics of the reaction of [bovine pancreatic] RNase A with cyclic cytidine 2'',3''-phosphate as substrate were investigated as a function of temperature at pH 5 and ionic strength 0.1 M. A conformational change near 32.degree. C may be involved in the rate-limiting step of the reaction mechanism. This conformational change may be the same one that was observed in studies of the free enzyme and of enzyme-inhibitor complexes near the same temperature.