Title

Effects of Intense Electric Fields on the Double Proton Transfer in the Watson-Crick Guanine-Cytosine Base Pair

Source of Publication

Journal of Physical Chemistry B

Abstract

Copyright © 2018 American Chemical Society. The double proton transfer reaction in the guanine-cytosine (GC) base pair is studied, using density functional theory, to understand the chances of mutations under the effect of uniform electric fields in the order of 108 to 109 V m-1. On the basis of potential energy surfaces, reaction Gibbs energies, equilibrium constants, imaginary frequencies, forward and reverse barrier heights, tunneling-corrected rate constants, half-lives of the forward and reverse reactions, percent tautomerization, and Boltzmann distributions, it was found that fields ≥+3.60 × 109 V m-1 facilitate the mutation in the GC base pair and reduce the rectification of point mutations. Fields applied along the double proton transfer in the -x (defined in the C to G direction) direction favor the canonical over the rare tautomers. Tunneling-corrected rate constants of the forward reaction increase exponentially with stronger fields in the -x direction and follow a Gaussian curve for the reverse reaction.

Document Type

Article

First Page

8631

Last Page

8641

Publication Date

9-20-2018

DOI

10.1021/acs.jpcb.8b05053

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