Faculty of Pharmaceutical Sciences, Division of Colloid and Surface Science, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamasaki, Noda, Chiba 278-8510, Japan.
Mol Pharm. 2023 Jul 3;20(7):3549-3558. doi: 10.1021/acs.molpharmaceut.3c00169. Epub 2023 Jun 19.
Ketoprofen (KP), which causes photosensitivity by interacting with serum albumin (SA), and three drugs, ibuprofen (IBP), naproxen (NPX), and diazepam (DZP), which share the same binding site, were investigated for their interaction with bovine SA (BSA). For KP, DZP, and IBP, where drug-concentration-dependent quenching of BSA-intrinsic fluorescence was observed, a modified Stern-Volmer plot showed that dynamic quenching was dominant for KP and static quenching was dominant for DZP and IBP. However, this alone cannot be compared with NPX. Therefore, by performing singular value decomposition (SVD) fluorescence spectroscopy, we were able to find the behavior of the drug-concentration-dependent Langmuir-type principal component vectors. obtained by the Langmuir equation showed a high correlation with the static extinction constant . Therefore, indicates the association constant of the drug with BSA and it was found that NPX and IBP had higher values than KP. Finally, in the analysis of the temperature factors of amino acid residues in each drug-binding region and Trp residues, KP and NPX significantly reduced these temperature factors whereas DZP and IBP hardly changed them. This result is consistent with the dynamic and static quenching dominance in the total quenching mechanism. Summarizing the results so far, it was shown that penetration into the hydrophobic core inside BSA can be achieved not only by one of the multiple aromatic rings and propionic acid groups but also by the joint effect of both. In this study, SVD enabled us to extract information on drug adsorption to BSA from fluorescence spectra. Furthermore, the application of SVD is expected to make it possible to perform fluorescence analysis for drug binding to proteins without being limited by the fluorescence properties of the drug.
酮洛芬（KP）与血清白蛋白（SA）相互作用会引起光致敏性，而布洛芬（IBP）、萘普生（NPX）和地西泮（DZP）这三种药物与 SA 具有相同的结合位点，因此研究了它们与牛 SA（BSA）的相互作用。对于 KP、DZP 和 IBP，观察到药物浓度依赖性猝灭 BSA 内荧光，经修正的 Stern-Volmer 图表明，KP 主要为动态猝灭，DZP 和 IBP 主要为静态猝灭。但是，这与 NPX 无法直接进行比较。因此，通过进行奇异值分解（SVD）荧光光谱分析，我们能够找到药物浓度依赖型 Langmuir 型主分量向量的行为。由 Langmuir 方程获得的药物浓度依赖型 Langmuir 型主成分向量与静态消光常数呈高度相关性。因此， 表示药物与 BSA 的结合常数，结果发现 NPX 和 IBP 的 值高于 KP。最后，在分析每个药物结合区域和色氨酸残基的氨基酸残基的温度因子时，KP 和 NPX 显著降低了这些温度因子，而 DZP 和 IBP 几乎没有改变它们。这一结果与总猝灭机制中动态和静态猝灭的主导地位一致。综上所述，结果表明，不仅可以通过多个芳环和丙酸基团中的一个，还可以通过两者的共同作用，使 KP 和 NPX 穿透到 BSA 内部的疏水区。在本研究中，SVD 使我们能够从荧光光谱中提取有关药物吸附到 BSA 的信息。此外，SVD 的应用有望使我们能够在不受药物荧光性质限制的情况下，对药物与蛋白质的结合进行荧光分析。
