Model calculations for the base-pairing specificity of mutagenic exocyclic DNA adduct 1,N 6-ethenoadenine

Abstract

1,N 6-ethenoadenine (eA) has been studied more extensively due to highly fluorescent and mutagenic nature. We report the model calculations for the base-pairing specificity of mutagenic 1,N 6-ethenoadenine adduct. To shed insight into mutagenic process of DNA damage based on geometrical characteristics, electronic properties, B3LYP, M06, B97D, and wB97XD methods have been employed for these model calculations. Single point energy calculation at MP2/6-311++G** levels on corresponding B3LYP, M06, B97D, wB97XD-optimized geometries have also been carried out to better estimate the hydrogen-bonding strengths. The polarisable conductor calculation model (CPCM-UAKS) that accounts for the overall polarizability of the solvent has also been employed. The computed reaction enthalpy values concluded that both guanine and thymine are most favorable candidates to be misincorporated to 1,N 6-ethenoadenine adduct, which also in good agreement to experimental report (Leonard, Biochemistry 33: 4755–4761, 79).