Solvatochromic Effect for the Denaturation and Mutation Processes in DNA: Computational Study
The influence of the environment on the proton transfer between nucleotide bases has crucial importance for denaturation and mutation processes in DNA. For quantitative description of these processes, activation (ΔE#) and reaction (ΔE) energies of the proton transfer as well as lactam-lactim (KT LL) and amino-imino (KT AI) tautomeric equilibrium constants by the quantum-chemical DFT method are calculated. It is shown that decrease in the environment polarity (Er) due to mixing of ethanol with water (solvatochromic effect) leads to a decrease in the activation energy of the proton transfer and to an increase of the mutation frequency (vm), and at the same time to the tendency of DNA to denaturation. Hence, energy and kinetic characteristics of the proton transfer may be used for quantitative estimation of a solvatochromic effect in DNA. The validity of the solvatochromic effect is confirmed by the bathochromic shift of the DNA absorption band in the UV spectrum.
Keywordssolvatochromic effect DNA denaturation mutation DFT calculations
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