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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (18): 1727-1732. 上一篇    下一篇

研究论文

百草枯与牛血清白蛋白结合作用的荧光光谱

颜承农*,1，张华新1，刘义2，梅平1，李克华1，童金强1   

  1. (1长江大学化学与环境工程学院 荆州 434020)
    (2武汉大学化学与分子科学学院 武汉 430072)
  • 投稿日期:2004-12-27 修回日期:2005-05-20 发布日期:2010-12-10
  • 通讯作者: 颜承农

Fluorescence Spectra of the Binding Reaction between Paraquat and Bovine Serum Albumin

YAN Cheng-Nong*,1, ZHANG Hua-Xin1, LIU Yi2, MEI Ping1, LI Ke-Hua1, TONG Jin-Qiang1   

  1. (1 College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020)
    (2 College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072)
  • Received:2004-12-27 Revised:2005-05-20 Published:2010-12-10
  • Contact: YAN Cheng-Nong

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被引次数

142 | 47

在模拟动物体生理条件下, 用荧光光谱和紫外-可见吸收光谱法研究了在不同温度下, 百草枯(PQ)与牛血清白蛋白(BSA)结合反应的光谱行为. 试验发现, PQ对BSA有较强的荧光猝灭作用. 用Stern-Volmer和Lineweaver-Burk方程分别处理试验数据, 发现BSA与PQ发生反应生成了新的复合物, 属于静态荧光猝灭, 发生分子内的非辐射能量转移. 根据F?rster的偶极-偶极非辐射能量转移理论计算出结合位置距离212位色氨酸残基2.07 nm. 由Lineweaver-Burk方程求出了不同温度下反应时复合物的形成常数KLB (297 K: 2.035×104 L•mol－1; 304 K: 3.256×104 L•mo－1; 311 K: 2.889×104 L•mol－1)及对应温度下结合反应的热力学参数(⊿HØ＝18.50 kJ•mol－1;⊿SØ＝144.7 J•K－1/145.2 J•K－1/141.0 J•K－1; ⊿GØ＝－24.50 kJ•mol－1/－25.66 kJ•mol－1/－25.36 kJ•mol－1), 证明二者主要靠疏水作用力结合. 同时用三维荧光光谱及同步荧光光谱法探讨了PQ对BSA构象的影响, 为预防和医治PQ中毒提供了重要依据.

关键词: 百草枯, 牛血清白蛋白, 结合反应, 热力学参数, 吸收光谱, 三维荧光光谱

Under the imitated physiological condition of animal body, the binding of paraquat to bovine serum albumin (BSA) was studied by fluorescence spectrum and ultra-violet spectrum. It was shown that this compound has a quite strong ability to quench the fluorescence launching from BSA. After analyzing the fluorescence quenching data according to Stern-Volmer equation and Lineweaver-Burk double-reciprocal equation, we found that BSA had reacted with paraquat and formed a certain new compound. The quenching belonged to static fluorescence quenching, with non-radiation energy transfer happening within single molecule. The binding locality was an area 2.07 nm away from tryptophan residue-212 in BSA based on F?rster’s non-radiation energy transfer mechanism. According to Lineweaver-Burk equation, KLB (297 K: 2.035×104 L•mol－1; 304 K: 3.256×104 L•mo－1; 311 K: 2.889×104 L•mol－1), the forming constants of the compound at different temperatures and the thermodynamic parameters (⊿HØ＝18.50 kJ•mol－1; ⊿SØ＝144.7 J•K－1/145.2 J•K－1/141.0 J•K－1; ⊿GØ＝－24.50 kJ•mol－1/－25.66 kJ•mol－1/－25.36 kJ•mol－1) at correspondence temperatures were obtained. The latter shows that binding power between them is mainly the hydrophobic interaction. The effect of paraquat on the conformation of BSA was analyzed by three-dimensional fluorescence spectra, contour spectra and synchronous spectra, and some useful information was offered for preventing animals from infecting paraquat and curing those who had caught it.

Key words: paraquat, bovine serum albumin, binding reaction, thermodynamic parameter, absorption spectra, three-dimensional fluorescence spectra