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在模拟动物体生理条件和不同温度下,用荧光光谱和紫外-可见吸收光谱研究二乙酰乙肟(DAM)与牛血清白蛋白(BSA)结合反应的光谱行为。用Stern-Volmer和Lineweaver-Burk方程分别处理试验数据,发现BSA与DAM反应生成新的复合物,属于静态荧光猝灭。求出反应时复合物的形成常数K_(LB)(340.10L·mol~(-1))、热力学参数(△H~θ=-58.10kJ·mol~(-1),△S~θ=-145.3J·K~(-1),△G~θ=-14.16kJ·mol~(-1)与结合位点数(1.061)。位点竞争实验结果显示DAM与BSA的作用位置主要在BSA的SiteⅠ(sub-domainⅡA)位,根据F(o|¨)rster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2.36nm,证明二者主要靠范德华力和氢键结合。同时用同步荧光光谱和三维荧光光谱法探讨DAM对BSA构象的影响。为阐明DAM的毒理效应和生物学效应提供重要信息。
The fluorescence spectra and UV-Vis absorption spectra were used to study the spectral behavior of diacetylacetone oxime (DAM) bound with bovine serum albumin (BSA) under physiological conditions and at different temperatures. Stern-Volmer and Lineweaver-Burk equations were used to process the experimental data respectively. It was found that BSA reacts with DAM to form a new complex, which belongs to the static fluorescence quenching. The formation constants K_ (LB) (340.10L · mol ~ (-1)) of the complex were obtained. The thermodynamic parameters (ΔH ~ θ = -58.10kJ · mol -1, △ S ~ 145.3J · K -1, ΔG ~ θ = -14.16kJ · mol -1 and the number of binding sites (1.061). The results of site competition experiments showed that the sites of DAM and BSA were mainly located in SiteⅠ According to the theory of F (o | ¨) rster dipole-dipole non-radiative energy transfer, the position of the tryptophan residue at position 212 is calculated to be 2.36 nm, which proves that the two mainly depend on van der Waals forces and hydrogen Key combination.The effects of DAM on the conformation of BSA were investigated by simultaneous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy, providing important information for elucidating the toxicological effects and biological effects of DAM.