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Updated: Apr 15, 2026

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
Computational study of a model system of enzyme-mediated [4+2] cycloaddition reaction
Evgeniy G Gordeev1, Valentine P Ananikov1
1Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow, Russia.
Abstract:
A possible mechanistic pathway related to an enzyme-catalyzed [4+2] cycloaddition reaction was studied by theoretical calculations at density functional (B3LYP, O3LYP, M062X) and semiempirical levels (PM6-DH2, PM6) performed on a model system. The calculations were carried out for the key [4+2] cycloaddition step considering enzyme-catalyzed biosynthesis of Spinosyn A in a model reaction, where a reliable example of a biological Diels-Alder reaction was reported experimentally. In the present study it was demonstrated that the [4+2] cycloaddition reaction may benefit from moving along the energetically balanced reaction coordinate, which enabled the catalytic rate enhancement of the [4+2] cycloaddition pathway involving a single transition state. Modeling of such a system with coordination of three amino acids indicated a reliable decrease of activation energy by ~18.0 kcal/mol as compared to a non-catalytic transformation.
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