Interpretation of pH Profiles

The use of pH studies to determine chemical mechanisms of action of enzyme-catalyzed reactions is probably their most important application in enzymology 

Which pH profiles do we look at, if we want to use the pH studies to determine the chemical mechanism The pH profiles that will be of the most value will be (Cleland, 1970, 1982)  

The Ki values in these profiles represent the equilibrium dissociation constants from the enzyme form present under the reaction conditions. The pKt values seen in these profiles are thus the correct ones in either the molecule which combines with the enzyme, or the enzyme form it combines with. Correct pKg values are seen, and such profiles are good candidates for temperature variation or solvent perturbation studies to identify the groups involved. 

These profiles usually have the following forms  

Combination of Eqs. (14.60) and (14.61) gives the pH dependence of the apparent hgand dissociation constant (7)  

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