荧光光度法研究甲氨蝶呤和蛋白质的相互作用

Fluorophotometric Study on the Interaction Between Methotrexate and Serum Albumin

应用荧光光度法研究了水溶液中甲氨蝶呤与牛血清白蛋白以及人血清白蛋白分子间的结合反应,讨论了甲氨蝶呤对蛋白质内源荧光的猝灭机理,测定出甲氨蝶呤与牛血清白蛋白以及人血清白蛋白的结合常数分别为6.76×10~5L·mol^(-1),2.69×10~5L·mol^(-1),相应的结合位点数分别为1.09,1.02。依据F(?)rster非辐射能量转移理论确定了供体一受体间的结合距离和能量转移效率,并用同步荧光技术考察了甲氨蝶呤对蛋白质构象的影响。

The combination of methotrexate（MTX）with bovine serum albumin（BSA）or human serum albumin（HSA）in aqueous solution was studied by fluorophotometry.It was shown that the combination constant were found to be 6.76×10^5 and 2.69×10^5L·mol^-1for BSA and HSA,and the number of binding sites（n）were 1.09 and 1.02,respectively.The mechanism of fluorescence quenching is a static quenching process.The binding distance between MTX and BSA or HSA and the rate of energy transfer were obtained based on the theory of F（？）rester energy transfer.The effect of methotrexate on the configuration of BSA or HSA was also analyzed using synchronous fluorescence technique.