Ministry of Education Key Laboratory of Analysis and Detection for Food Safety (Fuzhou University), Department of Chemistry, Fuzhou University, Fuzhou, 350002, China.
Analyst. 2011 Mar 7;136(5):973-8. doi: 10.1039/c0an00595a. Epub 2010 Dec 17.
A new fluorescence reagent, 2-methylbenzo[b][1,10]phenanthrolin-7(12H)-one (mBPO), synthesized in our laboratory was used as the probe for protein and its interaction with Bovine Serum Albumin (BSA) was investigated in detail in this paper. It was found that BSA had the ability to quench the fluorescence of mBPO at 411 nm (λ(ex) = 286 nm), and the quenched intensity of fluorescence was proportional to the concentration of BSA. Based on this fact, mBPO has been used as a fluorescence probe for the detection of BSA. Under the optimal conditions, the calibration graph is linear up to 0.5 mg L(-1) for BSA and the limit of detection (LOD) was 0.06 mg L(-1). The regression equation is y = 1048.8x + 7.2093 with R(2) = 0.9913. The mechanism for the interaction of mBPO with BSA was also studied, while the binding constant and the number of binding sites were calculated. According to the thermodynamics parameter, the binding mode between mBPO and BSA was deduced. The results suggested the interaction between mBPO and BSA to be hydrophobic force in nature. It also proved that the fluorescence quenching reaction was affected by the tryptophan residue of BSA. For there are two tryptophan (Trp) residues, in site 134 and site 212 of BSA, and mBPO maybe has interaction with them respectively.
一种新的荧光试剂，2-甲基苯并[b][1,10]菲咯啉-7(12H)-酮（mBPO），由我们实验室合成，被用作探针来研究其与牛血清白蛋白（BSA）的相互作用。结果表明，BSA 具有猝灭 mBPO 在 411nm 处荧光（λ(ex) = 286nm）的能力，荧光猝灭强度与 BSA 的浓度成正比。基于这一事实，mBPO 已被用作检测 BSA 的荧光探针。在最佳条件下，BSA 的校准曲线在 0.5mg L(-1) 范围内呈线性，检测限（LOD）为 0.06mg L(-1)。回归方程为 y = 1048.8x + 7.2093，R(2) = 0.9913。还研究了 mBPO 与 BSA 相互作用的机制，并计算了结合常数和结合位点数。根据热力学参数，推导出了 mBPO 与 BSA 之间的结合模式。结果表明，mBPO 与 BSA 之间的相互作用本质上是疏水作用力。这也证明了荧光猝灭反应受到 BSA 色氨酸残基的影响。因为 BSA 中有两个色氨酸（Trp）残基，分别位于 134 位和 212 位，mBPO 可能分别与它们相互作用。
