中国物理B ›› 2014, Vol. 23 ›› Issue (2): 27103-027103.doi: 10.1088/1674-1056/23/2/027103

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Damage mechanism of hydroxyl radicals toward adenine–thymine base pair

谈荣日a b c, 王东琪e, 张丰收b d f   

  1. a College of Communication and Electronics, Jiangxi Science & Technology Normal University, Nanchang 330013, China;
    b The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China;
    c Guizhou Key Laboratory for Photoelectric and Application, College of Science, Guizhou University, Guiyang 550025, China;
    d Beijing Radiation Center, Beijing 100875, China;
    e Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;
    f Center of Theoretical Nuclear Physics, National Laboratory of the Heavy Ion Accelerator of Lanzhou, Lanzhou 730000, China
  • 收稿日期:2013-10-19 修回日期:2013-11-14 出版日期:2013-12-12 发布日期:2013-12-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11025524 and 11161130520), the National Basic Research Program of China (Grant No. 2010CB832903), the Natural Science Foundation of Guizhou Province of China (Grant No. J20122141), the Fund in the framework of a Frontier of Novelty Program of the Chinese Academy of Sciences for one of the authors (Wang Dong-Qi) (Grant No. Y1515540U1), and the Research Fund for the Doctoral Program of Jiangxi Science and Technology Normal University (Grant No. 3000990110).

Damage mechanism of hydroxyl radicals toward adenine–thymine base pair

Tan Rong-Ri (谈荣日)a b c, Wang Dong-Qi (王东琪)e, Zhang Feng-Shou (张丰收)b d f   

  1. a College of Communication and Electronics, Jiangxi Science & Technology Normal University, Nanchang 330013, China;
    b The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China;
    c Guizhou Key Laboratory for Photoelectric and Application, College of Science, Guizhou University, Guiyang 550025, China;
    d Beijing Radiation Center, Beijing 100875, China;
    e Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;
    f Center of Theoretical Nuclear Physics, National Laboratory of the Heavy Ion Accelerator of Lanzhou, Lanzhou 730000, China
  • Received:2013-10-19 Revised:2013-11-14 Online:2013-12-12 Published:2013-12-12
  • Contact: Wang Dong-Qi, Zhang Feng-Shou E-mail:dwang@ihep.ac.cn;fszhang@bnu.edu.cn
  • About author:71.15.Mb; 82.30.Cf; 82.39.Pj; 87.15.Fh
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11025524 and 11161130520), the National Basic Research Program of China (Grant No. 2010CB832903), the Natural Science Foundation of Guizhou Province of China (Grant No. J20122141), the Fund in the framework of a Frontier of Novelty Program of the Chinese Academy of Sciences for one of the authors (Wang Dong-Qi) (Grant No. Y1515540U1), and the Research Fund for the Doctoral Program of Jiangxi Science and Technology Normal University (Grant No. 3000990110).

摘要: The adenine–thymine base pair was studied in the presence of hydroxyl radicals in order to probe the hydrogen bond effect. The results show that the hydrogen bonds have little effect on the hydroxylation and dehydrogenation happened at the sites, which are not involved in a hydrogen bond, while at the sites involved in hydrogen bond formation in the base pair, the reaction becomes more difficult, both in view of the free energy barrier and the exothermicity. With a 6-311++G(d,p) level of description, both B3LYP and MP2 methods confirm that the C8 site of isolated adenine has the highest possibility to form covalent bond with the hydroxyl radicals, though with different energetics: B3LYP predicts a barrierless pathway, while MP2 finds a transition state with an energy of 106.1 kJ/mol. For the dehydrogenation reactions, B3LYP method predicts that the free energy barrier increases in the order of HN9 < HN61 < HN62 < H2 < H8.

关键词: DNA damage, hydrogen bond effect, hydroxylation, dehydrogenation

Abstract: The adenine–thymine base pair was studied in the presence of hydroxyl radicals in order to probe the hydrogen bond effect. The results show that the hydrogen bonds have little effect on the hydroxylation and dehydrogenation happened at the sites, which are not involved in a hydrogen bond, while at the sites involved in hydrogen bond formation in the base pair, the reaction becomes more difficult, both in view of the free energy barrier and the exothermicity. With a 6-311++G(d,p) level of description, both B3LYP and MP2 methods confirm that the C8 site of isolated adenine has the highest possibility to form covalent bond with the hydroxyl radicals, though with different energetics: B3LYP predicts a barrierless pathway, while MP2 finds a transition state with an energy of 106.1 kJ/mol. For the dehydrogenation reactions, B3LYP method predicts that the free energy barrier increases in the order of HN9 < HN61 < HN62 < H2 < H8.

Key words: DNA damage, hydrogen bond effect, hydroxylation, dehydrogenation

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
82.30.Cf (Atom and radical reactions; chain reactions; molecule-molecule reactions) 82.39.Pj (Nucleic acids, DNA and RNA bases?) 87.15.Fh (Bonding; mechanisms of bond breakage)