分子光谱法研究5-氟尿嘧啶与牛血清白蛋白的相互作用

摘要

采用荧光、紫外和红外光谱法研究了5-氟尿嘧啶(5-FU)同牛血清白蛋白( BSA)的相互作用。5-FU对BSA的内源荧光具有强烈的猝灭作用。二者之间形成不发荧光的复合物是导致荧光猝灭的主要原因。计算了不同温度下两者的结合常数、结合位点数和相应的热力学参数。根据能量转移理论计算了作用距离。采用同步荧光光谱和红外光谱分析了5-FU对BSA构象的影响。%The binding of 5-fluorouracil(5-FU)to bovine serum albumin(BSA)was investigated by molecular spectroscopic(fluores-cence,ultraviolet and IR absorption) techniques. 5-FU can strongly quench the intrinsic fluorescence of BSA. The major quenching mechanism was suggested as the formation of nonflurorescence complex between 5-FU and BSA. The binding constants,the number of bonding sites and corresponding thermodynamic parameters at different temperature were calculated. Based on the Förster’s theory of non-radiation energy transfer,the binding distance was obtained. The effect of 5-FU on the conformation of BSA was analyzed u-sing synchronous fluorescence and IR spectroscopy.