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

Authors : Çağlar BAYAR

Pages : 31-40

Doi:10.46239/ejbcs.1225044

View : 23 | Download : 26

Publication Date : 2023-06-27

Article Type : Research Paper

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