Abstract

The binding peculiarities of methylene blue (MB), methyl violet (MV), and Hoechst 33258 (H33258) with human serum albumin (HSA) have been studied using the fluorescence spectroscopy method. Based on the fluorescence spectra analysis, it was shown that the HSA binds to the all mentioned ligands and forms complexes, meanwhile, a quenching of the ligand fluorescence occurs, which was found to be a static quenching type. The thermodynamic parameters (the entropy, enthalpy, and Gibbs free energy) were computed and it was revealed that the complex-formation takes place due to the hydrogen bonds and van der Waals interactions between the ligands and HSA. On the other hand, this process was revealed to be thermodynamically advantageous. The H33258 binds to HSA stronger as compared to the other two ligands, which becomes obvious because of the fluorescence spectra. It was also shown that in the case of MB binding to HSA at relatively high concentrations of HSA, the quenching occurs in two ways: by both static and dynamic modes.

中文翻译：

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低分子化合物与蛋白质复合物的光谱研究

摘要

使用荧光光谱法研究了亚甲基蓝（MB），甲基紫（MV）和Hoechst 33258（H33258）与人血清白蛋白（HSA）的结合特性。基于荧光光谱分析，表明HSA与所有提及的配体结合并形成络合物，同时，发生配体荧光的猝灭，发现其为静态猝灭类型。计算了热力学参数（熵，焓和吉布斯自由能），结果表明，由于配体与HSA之间的氢键和范德华相互作用，形成了络合物。另一方面，显示该方法在热力学上是有利的。与其他两个配体相比，H33258与HSA的结合更牢固，由于荧光光谱而变得显而易见。还显示出，在MB以相对较高的HSA浓度结合至HSA的情况下，猝灭以两种方式发生：通过静态和动态模式。