Electric-field induced mutation of DNA: a theoretical investigation of the GC base pair

It is known that intense external electric fields affect the proton transfer (PT) reactions in simple chemical systems, such as hydrated chlorhydric acid or formic acid dimer. Accordingly, electric fields might be used to modulate the PT reactions responsible for the spontaneous mutation mechanism in DNA. In this contribution, we investigate the effect of these fields on the tautomeric equilibria of the guanine-cytosine (GC) base pair in order to gain further insight into this hypothesis. This task is performed with both density functional theory (DFT) and second-order Moller-Plesset (MP2) approaches. Our results demonstrate that electric fields not only drastically alter the rate constants of PT but also tune the mechanism of the PT reactions in the GC base pair.