Abstract In this study, the multi-spectroscopic methods (UV-vis, fluorometric, circular dichroism), atomic force microscopy (AFM), cyclic voltammetry, molecular docking, and predictor online software (SwissADME-AdmetSAR) were used to investigate the interaction of complex [SnMe2Cl2(bu2bpy)] with human serum albumin (HSA). The calculated binding constant by UV-vis spectroscopy was about 104 M−1. Also, the polarity around the Trp-214 residue and the hydrophobicity were changed. The complex has a strong ability to quench the intrinsic fluorescence of HSA through static quenching procedure. The electrostatic force and hydrophobic interactions are dominant in the binding process based on the results of thermodynamic parameters (ΔH0 < 0 and ΔS0 > 0). The results of competitive binding measurements exhibited that the Sn(IV) complex bound to site II of HSA. Synchronous fluorescence, AFM, circular dichroism spectroscopy and molecular docking simulation results indicated that the binding of Sn(IV) complex to HSA induces the conformational changes of HSA. The in silico ADMET studies reveal that [SnMe2Cl2(bu2bpy)] and its ligand possess great biological potential. The results from cyclic voltammetry experiments also confirm interaction between HSA and Sn(IV) complex. Based on the non-radiative energy transfer theory of Forster, the binding distance between the complex (acceptor) and HSA (donor) was obtained (r = 1.77 nm). Furthermore, there was a good agreement between theoretical (molecular docking method) and experimental results. Finally, elucidation of the mechanism of anticancer activity revealed that Sn(IV) complex possesses potential cytotoxicity against MCF-7 breast cancer cells and is able to induce significant levels of apoptosis at concentrations below IC50 value. Graphical Abstract

中文翻译：

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[SnMe2Cl2(bu2bpy)] 的抗增殖活性和人血清白蛋白结合倾向：多光谱分析、原子力显微镜和计算研究

摘要 本研究采用多光谱方法（UV-vis、荧光、圆二色性）、原子力显微镜（AFM）、循环伏安法、分子对接和预测器在线软件（SwissADME-AdmetSAR）研究[SnMe2Cl2(bu2bpy)] 与人血清白蛋白 (HSA) 的复合物。通过紫外可见光谱计算的结合常数约为 104 M-1。此外，Trp-214 残基周围的极性和疏水性也发生了变化。该配合物通过静态猝灭过程具有很强的猝灭HSA固有荧光的能力。根据热力学参数（ΔH0 < 0 和 ΔS0 > 0）的结果，静电力和疏水相互作用在结合过程中占主导地位。竞争性结合测量的结果表明 Sn(IV) 复合物与 HSA 的位点 II 结合。同步荧光、AFM、圆二色光谱和分子对接模拟结果表明，Sn(IV)复合物与HSA的结合诱导了HSA的构象变化。计算机模拟 ADMET 研究表明 [SnMe2Cl2(bu2bpy)] 及其配体具有巨大的生物学潜力。循环伏安法实验的结果也证实了 HSA 和 Sn(IV) 复合物之间的相互作用。根据Forster的非辐射能量转移理论，得到复合物（受体）与HSA（供体）的结合距离（r = 1.77 nm）。此外，理论（分子对接方法）和实验结果之间存在良好的一致性。最后，对抗癌活性机制的阐明表明，Sn(IV) 复合物对 MCF-7 乳腺癌细胞具有潜在的细胞毒性，并且能够在低于 IC50 值的浓度下诱导显着水平的细胞凋亡。图形概要