Contribution of Phosphate Intrinsic Binding Energy to the Enzymatic Rate Acceleration for Triosephosphate Isomerase

We report that 80% of the enzymatic rate acceleration for the prototypical proton transfer from carbon catalyzed by triosephosphate isomerase can be directly attributed to the remote phosphodianion group of the substrate (R)-glyceraldehyde 3-phosphate, and that the intrinsic binding energy of this functional group in the transition state for enzyme-catalyzed enolization is 14 kcal/mol.