Abstract：
The interaction between di-n-butyl phthalate (DBP) and bovine serum albumin (BSA) in physiological Tris-HCl buffer at pH 7.4 was investigated by fluorescence quenching technique. By analyzing the fluorescence spectrum and intensity, it was observed that the DBP had a strong ability to quench the intrinsic fluorescence of BSA through a static quenching procedure. The binding constants K and the number of binding sites n of DBP with BSA were calculated to be 0.11 × 102 L·mol-1 and 0.52 at 298 K, respectively. The thermodynamic parameters of enthalpy change (ΔH) and entropy change (ΔS) were also calculated to be positive showing that hydrophobic forces might play a major role in the binding of DBP to BSA. The binding process was spontaneous in which Gibbs free energy change (ΔG) was negative. The distance (r) between the donor (BSA) and acceptor (DBP) was calculated to be 2.02 nm based on Forster\'s non-radiative energy transfer theory, which indicated that the energy transfer from BSA to DBP occurs with a high possibility. The synchronous fluorescence, three-dimensional fluorescence, and circular dichroism (CD) spectra showed that the binding of di-n-butyl phthalate to BSA induced conformational changes in BSA. The interaction between DBP and BSA can help researchers better understand the nature of poisons and serve people in the right way with first aid and detoxification.
摘要：
通过荧光猝灭技术研究了邻苯二甲酸二正丁酯（DBP）与牛血清白蛋白（BSA）在pH7.4的生理Tris-HCl缓冲液中的相互作用。通过分析荧光光谱和强度,观察到DBP具有通过静态猝灭程序猝灭BSA的固有荧光的强能力。在298K时，DBP与BSA的结合常数K和结合位点数n分别为0.11×102L·mol-1和0.52，分别。焓变（ΔH）和熵变（ΔS）的热力学参数也被计算为正，表明疏水性力可能在DBP与BSA的结合中起主要作用。结合过程是自发的，其中吉布斯自由能变化（ΔG）为负。根据Forster的非辐射能量转移理论，计算供体（BSA）和受体（DBP）之间的距离（r）为2.02nm。这表明从BSA到DBP的能量转移具有很高的可能性。同步荧光，三维荧光，圆二色性（CD）光谱表明，邻苯二甲酸二正丁酯与BSA的结合诱导了BSA的构象变化。DBP和BSA之间的相互作用可以帮助研究人员更好地了解毒药的性质，并以正确的方式为人们提供急救和排毒服务。
