Plots Of Initial Velocity Research Articles

On the interpretation of the pH variation of the maximum initial velocity of an enzyme-catalyzed reaction

1. 1. The variation of the maximum initial velocity for an enzymic reaction with pH is discussed in terms of the dissociation of two acid groups which affect the enzymic activity. 2. 2. The effect of ionic substrates upon the p K's of these groups is discussed. 3. 3. A method for calculating the p K's of the ionizable groups from plots of maximum initial velocity versus pH is developed. 4. 4. The effect of interaction between components of the buffer and the enzyme upon the values of the p K's is discussed. 5. 5. A method is suggested for the determination of the p K's of the ionizing groups in the free enzyme, in contrast to those in the enzyme-substrate complex.