杂多酸盐K_7[PTi_2W_(10)O_(40)]·6H_2O与人血清白蛋白(HSA)的作用研究

Study on the interaction between salt of heteropoly acid K_7[PTi_2W_(10)O_(40)]·6H_2O and human serum albumin

在模拟动物体生理条件下,用荧光和紫外光谱研究了在不同温度下杂多酸盐K7[PTi2W10O40]·6H2O(PM-19)与人血清白蛋白(HSA)结合反应的光谱行为。试验发现,PM-19对HSA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HSA与PM-19发生反应生成了新的复合物,属于静态荧光猝灭。由Lineweaver-Burk方程求出了不同温度下反应时复合物的形成常数KA(298 K:2.26×105L/mol;303 K:1.67×105L/mol;310K:1.01×105L/mol)及对应温度下结合反应的热力学参数(ΔH=-51.12kJ/mol;ΔS=-88.19/-87.85/-88.26 J/K;ΔG=-24.84/-24.50/-23.78kJ/mol),证明二者之间的主要作用力氢键和范德华力。根据F rster非辐射能量转移机制计算出了两者之间作用距离(4.21 nm)。同时用同步荧光光谱法探讨了PM-19对HSA构象的影响。

The interaction of salt of heteropoly acid （PM-19） with human serum albumin （HSA） was studied by fluorescence and ultraviolet spectrometry under simulative physiological conditions. The binding of PM-19 to HSA quenched the fluorescence emission from HSA and the results showed that static quenching occurred together with complex formation. The binding constants of the complex at different temperatures KA（298 K： 2.26 ×10^5 L/mol; 303 K： 1.67 ×10^5 L/mol; 310 K： 1.01×10^5L/mol） and the thermodynamic parameters （△H = -51.12 kJ/mol; △S = - 88.19/- 87.85/- 88.26 J/K; △G = - 24.84/- 24.50/- 23.78 kJ/mol） at correspondence temperatures were obtained according to Lineweaver-Burk equation. The latter indicated hydrogen bond and Van der Waar＇s forces played major roles in the binding of PM-19 to HSA. The binding distance was an are of 4.21 nm based on Forster＇s non-radiation energy transfer mechanism. The effect of PM-19 on the conformation of HSA was analyzed by synchronous fluorescence spectroscopy.