荧光法研究水胺硫磷与牛血清白蛋白的结合作用

Study on the Interaction between Isocarbophos and Bovine Serum Albumin by Fluorescence

在模拟动物体生理条件下,采用荧光光谱法研究了水胺硫磷与牛血清白蛋白(BSA)结合反应的光谱行为。研究表明,水胺硫磷对BSA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,发现水胺硫磷与BSA发生反应生成了新的复合物,属于静态荧光猝灭,且发生了分子内的非辐射能量转移,其结合常数为4.06×104L.mol-1。根据F rster非辐射能量转移理论,计算出水胺硫磷与BSA结合时其供体-受体间的结合距离为2.27 nm,能量转移效率为0.114。金属离子Ca2+、Fe3+、Zn2+、Cu2+的存在,会影响水胺硫磷与BSA的结合常数。

Under the imitated physiological condition of animal body, the binding of isocarbophos to bovine serum albumin（BSA） was studied by fluorescence spectrum. The results showed that this compound has a strong ability to quench the fluorescence launching from BSA. After analyzing the fluorescence quenching data according to Stem - Volmer equation and Lineweaver - Burk double - reciprocal equation, it was found that isocarbophos had reacted with BSA and formed a new complex. The quenching belonged to static fluorescence quenching,with non - radiation energy transfer happening within single molecule. The binding constant is 4.06 ×104 L·mol^-1. The binding distance and energy transfer efficiency between donor （BSA） and acceptor （isocarbophos） were obtained based on the theory of Forster spectroscopy energy transfer,their value are 2.27 nm and 0.114, respectively. The binding constant of isocarbophos to BSA was influenced in the presence of Ca^2＋ ,Fe^3＋ ,Zn^2＋ and Cu^2＋ .