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Updated: Aug 3, 2026

Hot Biological Catalysis: Isothermal Titration Calorimetry to Characterize Enzymatic Reactions
Published on: April 4, 2014
A view at the millennium: the efficiency of enzymatic catalysis
1Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
Abstract:
Binding TS in preference to S and increasing TDeltaS++by freezing out motions in E X S and E X TS have been accepted as the driving forces in enzymatic catalysis; however, the smaller value of DeltaG++ for a one-substrate enzymatic reaction, as compared to its nonenzymatic counterpart, is generally the result of a smaller value of DeltaH++. Ground-state conformers (E X NACs) are formed in enzymatic reactions that structurally resemble E X TS. E X NACs are in thermal equilibrium with all other E X S conformers and are turnstiles through which substrate molecules must pass to arrive at the lowest-energy TS. TS in E X TS may or may not be bound tighter than NAC in E X NAC.
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