The proficiency of a thermophilic chorismate mutase enzyme is solely through an entropic advantage in the enzyme reaction.

ABSTRACT: A study of the Thermus thermophilus chorismate mutase (TtCM) is described by using quantum mechanics (self-consistent-charge density-functional tight binding)/molecular mechanics, umbrella sampling, and the weighted histogram analysis method. The computed free energies of activation for the reactions in water and TtCM are comparable to the experimental values. The free energies for formation of near attack conformer have been determined to be 8.06 and 0.05 kcal/mol in water and TtCM, respectively. The near attack conformer stabilization contributes approximately 90% to the proficiency of the enzymatic reaction compared with the reaction in water. The transition state (TS) structures and partial atom charges are much the same in the enzymatic and water reactions. The difference in the elect

SUBMITTER: Zhang X 

PROVIDER: S-EPMC1317962 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature