Chen Xudong, Zhou Yan, Qu Peng, Zhao Xin Sheng
Beijing National Laboratory for Molecular Sciences, and Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
J Am Chem Soc. 2008 Dec 17;130(50):16947-52. doi: 10.1021/ja804628x.
Thermodynamics and dynamics of DNA hybridization/dehybridization at a terminal of a DNA duplex are investigated using steady-state fluorescence and fluorescence correlation spectroscopy (FCS). We introduce two pairs of dyes with different characteristic distances in fluorescence resonance energy transfer (FRET) to investigate the same process. The phenomenal discrepancy in the experimental observations between our two FRET pairs is incompatible with the traditional two-state model. We propose a so-called stretched exponential zipper (SEZ) model to successfully analyze the experimental data, through which the fundamental behavior of base-by-base hybridization/dehybridization is revealed. The dynamic parameters of the activation energy of single base-pair reaction derived from the two FRET pairs are consistent. The enthalpy change and entropy change of single base-pair formation are in agreement with theoretical prediction.
利用稳态荧光和荧光相关光谱（FCS）研究了DNA双链末端DNA杂交/解杂交的热力学和动力学。我们引入了在荧光共振能量转移（FRET）中具有不同特征距离的两对染料来研究同一过程。我们的两对FRET实验观察结果中的显著差异与传统的两态模型不相符。我们提出了一种所谓的拉伸指数拉链（SEZ）模型来成功分析实验数据，通过该模型揭示了逐个碱基杂交/解杂交的基本行为。从两对FRET得出的单碱基对反应活化能的动力学参数是一致的。单碱基对形成的焓变和熵变与理论预测相符。
