title: The Influence of the Terminal Phosphorothioate Diester Bond on the DNA Oxidation Process. An Experimental and Theoretical Approach.
abstract: In this study, the influence of the terminal phosphorothioate (PT) internucleotide bond in ds-DNA on the oxidation process was taken into consideration. The interaction of UV with the targeted oligonucleotide leads to an electron ejection and radical cation "hole" migration through the ds-DNA until it is trapped irreversibly in a suitable place. Phosphorothiate internucleotide bonds were detected in the bacterial genome; however, their role is still unclear. In this study a PAGE analysis of irradiated ds-DNA showed that the degradation rea ction was slowed down by the presence PT next to the anthraquinone moiety. Further, theoretical study shows that [RP] AQ-PS-dG can adopt a slightly lower ionisation potential energy and triplet excited state with a subsequent slightly higher adiabatic electron affinity value in comparison with [SP] AQ-PS-dG and AQ-PO-dG. Moreover, the energy gap between HOMO and LUMO, indicated the radical stabilisation properties of [RP] AQ-PS-dG, which can hinder the charge transfer through ds-DNA.
authors.affiliation: Food Science Department, Medical University of Lodz, ul. Muszynskiego 1, 90-151 Lodz, Poland. Bolek.Karwowski@wp.pl.
authors.forename: Boleslaw T
authors.initials: BT
authors.lastname: Karwowski
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D053837:DNA Cleavage / Q000528:radiation effects*; D004583:Electrons; D006151:Guanosine / Q000031:analogs & derivatives / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D054735:Phosphorothioate Oligonucleotides / Q000737:chemistry*; D055672:Static Electricity; D013816:Thermodynamics; D014466:Ultraviolet Rays
chemical_list: D000880:Anthraquinones; D054735:Phosphorothioate Oligonucleotides; D006151:Guanosine; C046215:8-hydroxyguanosine; D004247:DNA
keywords: DNA damage; UVA radiation; charge transfer; oxidation process; phosphorothioate