荧光猝灭法研究胆红素与牛血清白蛋白的相互作用

A study on interaction of bilirubin with bovine serum albumin by fluorescence quenching spectroscopy

在模拟生理条件下,利用荧光猝灭法研究了胆红素(BR)和牛血清白蛋白(BSA)的相互作用。结果表明胆红素对BSA有较强的荧光猝灭作用,两者形成了新的复合物,属于静态荧光猝灭,发生了分子内的非辐射能量转移。计算了不同温度下的结合位点数n,结合常数KA,以及对应的热力学参数ΔG,ΔH和ΔS。根据Foster非辐射能量转移理论确定了胆红素和BSA间的结合距离r。此外,利用同步荧光光谱,分析了胆红素对牛血清白蛋白构象的影响。

The mutual interaction of bilirubin （BR） with bovine serum albumin （BSA） was investigated using fluore-scence quenching spectroscopy under physiological conditions.It was proved that the fluorescence quenching of BSA by bilirubin was the result of the formation of bilirubin-BSA complex.And the quenching belonged to static fluorescence quenching.The binding site number n and the binding constant Ka,corresponding thermodynamic parameters ΔG,ΔH and ΔS at different temperatures were calculated.The binding distance between the bilirubin and BSA was also obtained based on the theory of non-radiation energy transfer.Moreover,the effect of bilirubin on the conformation of BSA was also analyzed by using synchronous fluorescence spectroscopy.