【作者】 节家龙； 宋迪； 苏红梅；

【Author】 Jialong Jie;Di Song;Hongmei Su;State Key Laboratory of Molecular Reaction Dynamics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences;

【机构】 中国科学院化学研究所分子反应动力学国家重点实验室；

【摘要】 水分子不仅通过溶剂效应影响质子转移过程的热力学参数,而且有可能扮演反应过程中接收,传递,或者提供质子的角色。DNA碱基的质子转移过程往往与溶剂水分子相关。因此,深入理解溶剂水分子在DNA碱基质子转移过程中的作用将显得十分重要。我们结合理论模型和相关实验,研究了溶剂水分子参与的G碱基单电子氧化后直接脱质子到水溶液中的过程。理论上,我们分别建立了考虑PCM下3,4,和7水分子参与的脱质子模型,并且依据这三个模型预测了这个脱质子过程的能垒和速率常数。为了证明相关模型的合理性,我们设计了低温下通过LFP测量该过程速率常数和能垒的实验。通过实验值与理论值对比发现脱质子反应活性位点周围几个显性水分子的重要作用。通过这次研究,我们从机理上进一步认识了生物分子质子转移过程中溶剂水分子的重要性。更多还原

【Abstract】 Proton transfer processes in DNA bases are always related to solvent water molecules, and the water not only can alter the energetic of proton transfer processes but also have the potential to play a role as the proton donor, transporter or acceptor. Here, we performed joint theoretical modeling and experimentally studies by examining the deprontonation process of G+·. Theoretically, we established three combined microsolvation-PCM models. The energy barrier and the rate constant were predicted based on different models. In order to validate the theoretical models, we design transient UV-vis spectroscopy experiments under low-temperature conditions to measure the reaction energy barriers to compare with the calculated values. Further, the key roles played by surrounding water in deprotonation are closely examined and these finds provide a closely-coupled experimental and theoretical strategy for examining analogous proton transfer processes in aqueous water, which is ubiquitously present in biological systems.更多还原