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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (18): 2155-2158. 上一篇    

研究简报

氧化苦参碱与牛血清白蛋白相互作用的热力学研究

徐香玉 孙祥军 刘 敏 孙得志* 李林尉*   

  1. (聊城大学化学化工学院 聊城 252059)
  • 投稿日期:2009-01-08 修回日期:2009-03-20 发布日期:2009-12-31
  • 通讯作者: 孙得志

Thermodynamic Study on Interaction of Oxymatrine with Bovine Serum Albumin

Xu, Xiangyu Sun, Xiangjun Liu, Min Sun, Dezhi* Li, Linwei*   

  1. (College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059)
  • Received:2009-01-08 Revised:2009-03-20 Published:2009-12-31
  • Contact: Sun, Dezhi

被引次数

32

在298.15 K下, 应用等温滴定量热法和圆二色谱法研究了氧化苦参碱(OMT)与牛血清白蛋白(BSA)的相互作用, 并讨论了二者结合过程热力学性质的改变. 研究结果表明, BSA大分子上存在可结合OMT分子的两类位点. OMT分子与第一类位点相结合时, 结合过程的平衡常数、标准摩尔焓变和标准摩尔吉布斯自由能变分别为 ＝(2.14±0.31)×105, ＝(－1.07±0.50) kJ•mol－1, ＝(－30.4±0.4) kJ•mol－1, 最大可结合位点数为 N1＝(10.0±0.2), 该过程是以熵驱动为主的焓熵协同驱动过程. OMT 分子与第二类位点相结合时, ＝(6.84±0.32)×103, ＝(1.91±0.03) kJ•mol－1, ＝(－21.9±0.4) kJ•mol－1, N2＝(25.0±0.3), 该过程是熵驱动过程. 圆二色谱测试结果表明, 两类结合过程中, OMT与BSA的相互作用均导致了蛋白质二级结构构象及不同结构单元相对含量的变化.

关键词: 等温滴定量热法, 圆二色光谱, 氧化苦参碱, 牛血清白蛋白

The interaction of oxymatrine (OMT) with bovine serum albumin (BSA) was investigated by using nano-watt-scale isothermal titration calorimetry and circular dichroism (CD) spectrometry at 298.15 K. Changes of thermodynamic functions corresponding to the binding process were obtained and discussed. The results indicated that there were two classes of binding sites between BSA and OMT molecules. When the drug molecule binding to the first class of sites, the binding constant the standard changes of enthalpy and Gibbs free energy are (2.14±0.31)×105, (－1.07±0.50) kJ•mol－1 and (－30.4±0.4) kJ•mol－1, respectively. The possible largest number of binding site (N1) is (10.0±0.2). This type of binding is an enthalpy-entropy synergically driven process. On the second class of binding sites, the binding constant the standard changes of enthalpy and Gibbs free energy are (6.84±0.32)×103, (1.91±0.03) kJ•mol－1 and (－21.9±0.4) kJ•mol－1, respectively. The possible largest number of binding site (N2) is (25.0±0.3). This type of binding is an entropy driven process. The CD spectra showed that both the conformation and the relative contents of secondary structure units of BSA were changed by the two types of binding processes.

Key words: isothermal titration calorimetry, circular dichroism spectrometry, oxymatrine, bovine serum albumin