Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (8): 20240208.doi: 10.7503/cjcu20240208

• Physical Chemistry • Previous Articles     Next Articles

Theoretical Studies of Effect of Hydrogen Bond on Reaction of Hydroxyl Radicals and Guanine

WANG Yinghui1(), XUE Haoming2, MA Bin2, LI Zongxuan3, MA Yating2, MA Lei1, WEI Simin4()   

  1. 1.School of Science
    2.School of Civil Engineering
    3.School of Highway,Chang’an University,Xi’an 710064,China
    4.Co?construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry,Shaanxi University of Chinese Medicine,Xianyang 712083,China
  • Received:2024-04-23 Online:2024-08-10 Published:2024-05-13
  • Contact: WANG Yinghui E-mail:wangyinghui@chd.edu.cn;weismiccas@163.com
  • Supported by:
    the National Natural Science Foundation of China(22103007);the Science and Technology Youth Stars Project of Shaanxi Province, China(2023KJXX-063);the Key Research and Development Plan of Shaanxi Province, China(2024SF-YBXM-517);the Xi’an Science and Technology Plan Project, China(22GXFW0153);the Science and Technology Innovation Talent System Construction Plan of Shaanxi University of Chinese Medicine, China(2023-LJRC-03);the Innovation and Entrepreneurship Training Program for College Students, China(S202310710221);the Natural Science Foundation of Shaanxi Province, China(2024JC-YBQN-0586)

Abstract:

Hydroxyl radical(OH) is a representative reactive oxygen species(ROS) with high oxidation potential, and could lead to the indiscriminate chemical modification on DNA causing oxidative damage. Interestingly, it has documented that the reaction of OH and guanine(G) reveals hydrogen bond-dependent fashion. Due to the highly specific binding of triplex forming oligonucleotide(TFO) to target duplex DNA leading to various surroundings of G, it makes triplex DNA as a prototype model to be examined. Inspired by this, by selecting the building block of antiparallel triplex DNA-GGC motif as the substrate, a comprehensive theoretical investigation was performed to illuminate the influence of hydrogen bond on the obscure reaction of OH and G by structural analysis, HOMO calculation and mapping the energy profiles for both addition and hydrogen abstraction reactions. Results reveal that the G located in TFO is more susceptible to the attack of OH. In GGC base pair, the neutral radical G(-H2) could be formed by direct H-abstraction, where the participation of explicit water is adverse to H-abstraction from N2 of G. The electrophilic attack of OH to C8 of G resulting in 8-oxoG is the most favorable course due to the lowest energy barrier in comparison with H-abstraction pathway. And the stability of ion-pairs appears to significantly influence by hydrogen bond, which is less stable than the hydroxylated radicals different with free G. These results show clearly that the hydrogen bonds guide the reaction flux of OH and G.

Key words: Hydroxyl radical, Hydrogen bond, Antiparallel triplex DNA, Addition reaction, Hydrogen abstraction reaction

CLC Number: 

TrendMD: