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在模拟动物体生理条件下,用荧光光谱、三维荧光光谱、同步荧光光谱、紫外-可见吸收光谱等方法研究了在不同温度下,对硝基氯苯(PCNB)与牛血清白蛋白(BSA)结合反应的光谱行为。试验发现,PCNB对BSA有较强的荧光猝灭作用。用Stern-Volmer和Lineweaver-Burk方程及热力学方程分别处理试验数据,发现BSA与PCNB发生反应生成了新的复合物,属于静态荧光猝灭,得到了它们相互作用的生成常数KLB(1.557×104L/mol)、热力学参数(ΔHθ=-89.962kJ/mol,ΔSθ=-217.98J/K,ΔGθ=-23.93kJ/mol)和结合位点数(1.080)等。位点竞争实验结果显示PCNB与BSA的作用位置主要在BSA的SiteⅠ(Sub-domainⅡA)位。证明二者主要靠氢键和范德华力结合,同时用三维荧光光谱及同步荧光光谱法探讨了PCNB对BSA构象的影响,为研究PCNB的毒性和生物学效应提供了重要信息。
The effects of p-nitrobenzene (PCNB) and bovine serum albumin (BSA) were studied under different temperature conditions by fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, synchronous fluorescence spectroscopy and UV-Vis absorption spectroscopy. The spectral behavior of the binding reaction. It was found that PCNB has a strong fluorescence quenching effect on BSA. Stern-Volmer and Lineweaver-Burk equations and thermodynamic equations were used to process the experimental data respectively. It was found that BSA reacts with PCNB to generate new complex, which belongs to the static fluorescence quenching. The KLB (1.557 × 104L / mol), thermodynamic parameters (ΔHθ = -89.962 kJ / mol, ΔSθ = -217.98 J / K, ΔGθ = -23.93 kJ / mol) and number of binding sites (1.080). Site competition experiments showed that the site of action of PCNB and BSA was mainly in SiteⅠ (Sub-domainⅡA) of BSA. It is proved that both of them mainly depend on hydrogen bonding and van der Waals forces, and the influence of PCNB on the conformation of BSA is also discussed by three-dimensional fluorescence spectroscopy and synchronous fluorescence spectroscopy, which provides important information for studying the toxicity and biological effects of PCNB.