Hydrogen donor-acceptor fluctuations from kinetic isotope effects: a phenomenological model.

ABSTRACT: Kinetic isotope effects (KIEs) and their temperature dependence can probe the structural and dynamic nature of enzyme-catalyzed proton or hydride transfers. The molecular interpretation of their temperature dependence requires expensive and specialized quantum mechanics/molecular mechanics (QM/MM) calculations to provide a quantitative molecular understanding. Currently available phenomenological models use a nonadiabatic assumption that is not appropriate for most hydride and proton-transfer reactions, while others require more parameters than the experimental data justify. Here we propose a phenomenological interpretation of KIEs based on a simple method to quantitatively link the size and temperature dependence of KIEs to a conformational distribution of the catalyzed reaction. This mod

SUBMITTER: Roston D 

PROVIDER: S-EPMC3448806 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature