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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (6): 481-488. 上一篇    下一篇

研究论文

2',3'-二脱氧-2',3'-二去氢鸟嘌呤核苷构象稳定性的理论研究

何冰1, 薛英*,1,2, 郭勇1, 鄢国森1   

  1. (1四川大学化学学院 成都 610064)
    (2四川大学华西医学院生物治疗国家重点实验室 成都 610041)
  • 投稿日期:2006-06-23 修回日期:2006-09-22 发布日期:2007-03-28
  • 通讯作者: 薛英

Theoretical Study on the Conformational Stability of 2',3'-Dideoxy-2',3'-didehydroguanosine

HE Bing1; XUE Ying*,1,2; GUO Yong1; YAN Guo-Sen1   

  1. (1 College of Chemistry, Sichuan University, Chengdu 610064)
    (2 Key State Laboratory of Biotherapy, West China Medical College, Sichuan University, Chengdu 610041)
  • Received:2006-06-23 Revised:2006-09-22 Published:2007-03-28

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采用密度泛函方法在B3LYP/6-31＋G**水平上研究了2',3'-二脱氧-2',3'-二去氢鸟嘌呤核苷分子(D4G)的构象. 分别研究在气相中的孤立分子和一水合物异构体的相对稳定性和异构体之间的相互转变过程, 分析了水分子的参与对D4G异构体的相对稳定性和几何结构参数以及自然电荷的影响. 结果表明, 孤立的D4G分子在气相中存在8种稳定构象, 其中构象d4g-2是所有构象中最稳定的, 气相中D4G主要以d4g-2存在. 气相中各构象的相对稳定性为: d4g-2＞d4g-1＞d4g-5＞d4g-3＞d4g-6＞d4g-4＞d4g-8＞d4g-7. 计算得到的各构象键长和键角数据与实验值接近. 一个水分子的加入对D4G分子的构型参数有所影响, 基本不改变D4G分子各构象的稳定性顺序, 但构象转变的能垒有所提高. 氢键在分子构象中发挥了重要作用.

关键词: 2',3'-二脱氧-2',3'-二去氢鸟嘌呤核苷(D4G), 构象稳定性, 密度泛函理论, 溶剂效应

The DFT (B3LYP/6-31＋G**) method was used to study the conformations and isomerization of the isolated and monohydrated 2',3'-dideoxy-2',3'-didehydroguanosine (D4G) molecules in gas phase. The effects of one-water molecule on relative stabilities, conformational parameters and nature charges of D4G were analyzed. The results indicate that there are 8 stable conformers for D4G in gas phase. The conformer d4g-2 is the most stable form of all conformations in gas phase. The relative stability order is as follows: d4g-2＞d4g-1＞d4g-5＞d4g-3＞d4g-6＞d4g-4＞d4g-8＞d4g-7. The computational results are in good agreement with the available experimental ones. The addition of one-water molecule did not almost change the order of the relative stability and increased slightly the energy barriers of conformational isomerization of D4G. Hydrogen bonding played an important role in D4G conformations.

Key words: 2',3'-dideoxy-2',3'-didehydroguanosine (D4G), conformational stability, density functional theory, solvent effect