The Properties of Ribonuclease: a Study in Binding and Kinetics

The interaction between pancreatic ribonuclease and calf thymus DNA is studied as a function of kinetics and binding. It is found that native and denatured DNA bind strongly to RNase, and that the ratio. Kden/Knat = 5.7. It is also shown that at approximately equal concentrations of RNA and DNA, denatured DNA inhibits RNase hydrolysis of RNA by 83%, and native DNA inhibits by 43%. A gel method is found to be unsatisfactory for studying the binding of RNase to pyrimidine oligonucleotides; equilibrium dialysis is then tried, and the KB for the interaction between RNase and dinucleoside monophosphate is found to be approximately equal to 9. The kinetics of RNase activity is discussed and an experiment proposed for studying the enzyme's mechanism.