Deprotonation of Guanine Radical Cation in G-Quadruplex: A Combined Experimental and Theoretical Study
文献类型：期刊论文
| 作者 | Wang Yinghui1,2; Jie Jialong1,2; Zhao Hongmei1,2; Bai Yu1; Qin Peixuan3; Song Di1,2 |
| 刊名 | ACTA CHIMICA SINICA
 |
| 出版日期 | 2018-06-15 |
| 卷号 | 76期号:6页码:475-482 |
| 关键词 | G-quadruplex Guanine Radical Cation Deprotonation Reaction Activation Energy Potential Energy Profile |
| ISSN号 | 0567-7351 |
| DOI | 10.6023/A17120557 |
| 英文摘要 | G-Quadrupex can be a promising candidate as molecular electronic device due to the ability of transferring hole. Extensive studies have reported that fast deprotonation of guanine radical cation (G(center dot+)) to form a neutral radical G(-H)(center dot) is the most important reaction in competition with hole transfer in DNA, hindering potential applications of DNA in molecular electronics. We thus carry out joint experimental and theoretical studies on deprotonation of G(center dot+) in human telomere G-quadruplex AG(3)(T(2)AG(3))(3) by using nanosecond laser flash photolysis and quantum chemical calculations. Upon 355 nm laser photolysis of Na2S2O8, instantaneously generated SO4 center dot- radical oxidizes G base in the G-quadruplex to G(center dot+). In the time-resolved absorption spectra that record the reaction of G-quadruplex with SO4 center dot- at different temperatures, the transient absorptions of G(N(2)-H)center dot featured by absorption band at 640 nm are observed. It turns out that the G-quadruplex deprotonation product is G(N(2)-H)center dot and the deprotonation site is thereby validated to be amino proton. To obtain the activation energy of the G(center dot+) deprotonation in G-quadruplex, the N(2)-H deprotonation rate constants at different temperatures varying from 280 to 300 K in steps 5 K are measured at a high G-quadruplex concentration, where the deprotonation has been proved to be the rate-limiting step in our previous work. Based upon Arrhenius equation, the deprotonation activation energy of G(center dot+) in G-quadruplex is determined to be 20.0 +/- 1.0 kJ/mol. Further, the potential energy profile for the G(center dot+) deprotonation in G-quadruplex is calculated at M062X/6-31G(d) level by carefully taking into account hydration environment of G(center dot+) in G-quadruplex. The calculated energy bather of 26.4 kJ/mol matches with the measured activation energy value, indicating the calculated potential energy profile can describe the deprotonation process of G(center dot+) in the G-quadruplex. These theoretical and experimental results provide valuable dynamics information and mechanistic insights for potential applications of DNA structures in electronic device. |
| 语种 | 英语 |
| WOS记录号 | WOS:000442409600008 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/42375]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Song Di |
| 作者单位 | 1.Chinese Acad Sci, BNLMS, Inst Chem, Beijing 100190, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Beijing Sanfan Middle Sch, Beijing 100088, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang Yinghui,Jie Jialong,Zhao Hongmei,et al. Deprotonation of Guanine Radical Cation in G-Quadruplex: A Combined Experimental and Theoretical Study[J]. ACTA CHIMICA SINICA,2018,76(6):475-482. |
| APA | Wang Yinghui,Jie Jialong,Zhao Hongmei,Bai Yu,Qin Peixuan,&Song Di.(2018).Deprotonation of Guanine Radical Cation in G-Quadruplex: A Combined Experimental and Theoretical Study.ACTA CHIMICA SINICA,76(6),475-482. |
| MLA | Wang Yinghui,et al."Deprotonation of Guanine Radical Cation in G-Quadruplex: A Combined Experimental and Theoretical Study".ACTA CHIMICA SINICA 76.6(2018):475-482. |
入库方式： OAI收割
来源：化学研究所
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