Molecular modeling and thermodynamics of the interaction between DNA base pairs and radon originated ionizing alpha radiation

Ionizing alpha radiation (He2+) is known to adversely affect human DNA, but the biochemical reasoning not clear yet. Relatedly, present computational study was conducted investigating effects of ionizing onto Watson-Crick type DNA base pairs (nucleotides) Adenine-Thymine (AT’) and Guanine-Cytosine (GC’). The long-range cation (He2+)−π interactions were modeled for this purpose. A hybrid DFT functional M06-2X used with 6-31G(d,p) 6-311G(d) basis sets at unrestricted level. results showed that severely changed considered pairs’ hydrogen bond lengths their interaction enthalpies Gibbs free energies, however, more drastic changes observed in GC’ rather than AT’. This observation also supported by frontier molecular orbital analyses performed. favored form He2+ complexes (oxidize) AT’ consequently these had exothermic energies (formed spontaneously) It could be highlighted modeling proposed would contribute elucidation uncertainty field.