Department of Biosciences, Medicinal Chemistry Laboratory, New Delhi, India.
Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India.
J Biomol Struct Dyn. 2023 Aug-Sep;41(13):6377-6393. doi: 10.1080/07391102.2022.2107077. Epub 2022 Aug 4.
Hydroxychloroquine (HCQ), a quinoline based medicine is commonly used to treat malaria and autoimmune diseases such as rheumatoid arthritis. Since, human serum albumin (HSA) serves as excipient for vaccines or therapeutic protein drugs, it is important to understand the effect of HCQ on the structural stability of HSA. In this study, the binding mechanism of HCQ and their effect on stability of HSA have been studied using various spectroscopic techniques and molecular dynamic simulation. The UV-VIS results confirmed the strong binding of HCQ with HSA. The calculated thermodynamics parameters confirmed that binding is spontaneous in nature and van der Waals forces and hydrogen bonding are involved in the binding system which is also confirmed by molecular docking results. The steady-state fluorescence confirms the static quenching mechanism in the interaction system, which was further validated by time-resolved fluorescence. The synchronous fluorescence confirmed the more abrupt binding of HCQ with tryptophan residue of HSA compared to Tyr residue of HSA. Isothermal titration calorimetry (ITC) was done to validate the thermodynamics parameters of HSA-HCQ complex in one experiment, supporting the values obtained from the spectroscopic techniques. The circular dichroism (CD) demonstrated that the HCQ affected the secondary structure of HSA protein by reducing their α-helical content. The docking and molecular dynamic simulation results further helped in understanding the effect of HCQ on conformational changes of HSA. Overall, present work defined the physicochemical properties and interaction mechanism of HCQ with HSA that have extensively been elucidated by both and approaches.Communicated by Ramaswamy H. Sarma.
羟氯喹（HCQ）是一种基于喹啉的药物，通常用于治疗疟疾和类风湿性关节炎等自身免疫性疾病。由于人血清白蛋白（HSA）可用作疫苗或治疗性蛋白药物的赋形剂，因此了解 HCQ 对 HSA 结构稳定性的影响非常重要。在这项研究中，使用各种光谱技术和分子动力学模拟研究了 HCQ 的结合机制及其对 HSA 稳定性的影响。紫外可见光谱（UV-VIS）结果证实了 HCQ 与 HSA 的强结合。计算的热力学参数证实，结合是自发的，范德华力和氢键参与结合体系，这也得到了分子对接结果的证实。稳态荧光证实了相互作用体系中存在静态猝灭机制，这一机制进一步通过时间分辨荧光得到了验证。同步荧光证实了与 HSA 的色氨酸残基相比，HCQ 与 HSA 的酪氨酸残基的结合更为突然。等温滴定量热法（ITC）用于在一次实验中验证 HSA-HCQ 配合物的热力学参数，支持从光谱技术获得的值。圆二色性（CD）表明，HCQ 通过降低其α-螺旋含量来影响 HSA 蛋白的二级结构。对接和分子动力学模拟结果进一步有助于理解 HCQ 对 HSA 构象变化的影响。总的来说，目前的工作定义了 HCQ 与人血清白蛋白（HSA）相互作用的物理化学性质和相互作用机制，这已通过和方法得到了广泛的阐明。
