The Influence of the Terminal Phosphorothioate Diester Bond on the DNA Oxidation Process. An Experimental and Theoretical Approach

Molecules

Boleslaw T. Karwowski¹ 

[1] Food Science Department, Medical University of Lodz, ul. Muszynskiego 1, 90-151 Lodz, Poland; E-Mail

关键词: phosphorothioate;    DNA damage;    UVA radiation;    oxidation process;    charge transfer;   

DOI  :  10.3390/molecules200712400

来源: mdpi

【 摘 要 】

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 [R_P] 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 [S_P] AQ-PS-dG and AQ-PO-dG. Moreover, the energy gap between HOMO and LUMO, indicated the radical stabilisation properties of [R_P] AQ-PS-dG, which can hinder the charge transfer through ds-DNA.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.