| Abstrakt: |
Binding TS in preference to S and increasing TΔS by freezing out motions in E·S and E·TS have been accepted as the driving forces in enzymatic catalysis; however, the smaller value of ΔG for a one-substrate enzymatic reaction, as compared to its nonenzymatic counterpart, is generally the result of a smaller value of ΔH. Ground-state conformers (E·NACs) are formed in enzymatic reactions that structurally resemble E·TS. E·NACs are in thermal equilibrium with all other E·S conformers and are turnstiles through which substrate molecules must pass to arrive at the lowest-energy TS. TS in E·TS may or may not be bound tighter than NAC in E·NAC. |
