Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Nov;97:1089-100. doi: 10.1016/j.saa.2012.07.034. Epub 2012 Aug 4.
Human serum albumin (HSA) and holo transferrin (TF) are two serum carrier proteins that are able to interact with each other, thereby altering their binding behavior toward their ligands. During the course of this study, the interaction between HSA-PPIX and TF, in the presence and absence of lomefloxacin (LMF), was for the first time investigated using different spectroscopic and molecular modeling techniques. Fluorescence spectroscopy experiments were performed in order to study conformational changes of proteins. The RLS technique was utilized to investigate the effect of LMF on J-aggregation of PPIX, which is the first report of its kind. Our findings present clear-cut evidence for the alteration of interactions between HSA and TF in the presence of PPIX and changes in drug-binding to HSA and HSA-PPIX complex upon interaction with TF. Moreover, molecular modeling studies suggested that the binding site for LMF became switched in the presence of PPIX, and that LMF bound to the site IIA of HSA. The obtained results should give new insight into research in this field and may cast some light on the dynamics of drugs in biological systems.
人血清白蛋白（HSA）和全转铁蛋白（TF）是两种血清载体蛋白，能够相互作用，从而改变它们对配体的结合行为。在本研究过程中，首次使用不同的光谱和分子建模技术研究了 HSA-PPIX 和 TF 之间在洛美沙星（LMF）存在和不存在的情况下的相互作用。荧光光谱实验用于研究蛋白质的构象变化。RLS 技术用于研究 LMF 对 PPIX J-聚集的影响，这是此类研究的首次报道。我们的发现为 PPIX 存在时 HSA 和 TF 之间相互作用的改变以及与 TF 相互作用时 HSA 和 HSA-PPIX 复合物中药物结合的变化提供了明确的证据。此外，分子建模研究表明，在 PPIX 存在下，LMF 的结合位点发生了转换，LMF 结合到 HSA 的 IIA 位点。所得结果应能为该领域的研究提供新的见解，并可能为生物系统中药物的动力学提供一些启示。
