铜、锌离子对齐墩果酸与蛋白质相互作用的影响

Effects of metal ions on the interaction between oleanic acid and Bovine Serum Albumin

使用荧光光谱和紫外吸收光谱研究金属离子存在下对齐墩果酸(OA)与牛血清白蛋白(BSA)相互作用的影响。实验结果表明,生理pH值条件下齐墩果酸对牛血清白蛋白的荧光猝灭可能是一个单一的静态猝灭过程。求得了OA与BSA相互作用的结合常数为6.16×103L.mol-1。Zn2+或Cu2+存在下,OA对BSA的荧光猝灭类型没有发生改变。金属离子的参与使齐墩果酸与牛血清白蛋白的结合常数增大。结合位点数始终维持在1左右。

The interaction between oleanic acid and bovine serum albumin（BSA）in the presence of metal ions using fluorescence and UV absorption spectrometric methods was studied.Results obtained from analysis of fluorescence spectra indicated that in physiological condition（pH 7.4）,the quenching of oleanic acid to BSA is probably a single static quenching process.The binding constant of OA with bovine serum albumin was found to be K=6.16×103 L·mol-1.Whereas,in the presence of Cu2＋and Zn2＋,the type of BSA intrinsic fluorescence quenching was not changed.It was discovered that the apparent association constant increases in the presence of Cu2＋and Zn2＋.The number of binding sites of OA on BSA was still about 1.