School of Pharmaceutical Sciences, Liaoning University, Shenyang 110036, China; Shenyang Key Laboratory for Causes and Drug Discovery of Chronic Diseases, Liaoning University, Shenyang 110036, China.
School of Pharmaceutical Sciences, Liaoning University, Shenyang 110036, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Dec 15;323:124929. doi: 10.1016/j.saa.2024.124929. Epub 2024 Aug 2.
The competition among drugs for binding to plasma proteins is regarded as a pharmacokinetic drug interaction. Competition between antitumor agents and other drugs for plasma protein binding can alter the free concentration of the drug, potentially impacting its efficacy and increasing the risk of toxic side effects. Through a range of spectroscopic techniques, this study examined the interaction between limonin and human serum albumin (HSA) in the context of berberine (Ber) and curcumin (Cur) under physiological conditions to clarify the binding mechanisms of binary and ternary systems at the molecular level. As demonstrated by fluorescence quenching experiments, Static quenching was identified as the mechanism of interaction between HSA and limonin. The results of site competition experiments indicated that the binding site between limonin and HSA was site I, a result further supported by molecular docking simulations. Through the use of thermodynamic data calculations, it was determined that limonin forms a stable complex with HSA by establishing hydrogen bonds and van der Waals forces. Circular dichroism (CD) spectroscopy, three-dimensional (3D) fluorescence spectroscopy, and synchronous fluorescence spectroscopy (SFS) employed to validate the notion that limonin perturbed the microenvironment of amino acids and induced conformational changes in HSA. What's more, the presence of Ber or Cur was found to have further modified the alterations observed in the interaction between the original HSA-limonin binary system. In vitro cellular experiments showed that interaction with HSA reduced the antitumor activity of limonin. In contrast, adding Ber or Cur increased the inhibition rate of tumor cells. The coexistence of both Ber and Cur significantly diminished limonin's binding affinity to HSA. The current investigation enhances comprehension regarding the binding characteristics and interaction mechanisms involving limonin, Ber, Cur, and HSA. It explores the potential of HSA as a versatile drug carrier and furnishes theoretical underpinnings for co-administrative strategies.
药物与血浆蛋白结合的竞争被视为一种药代动力学的药物相互作用。抗肿瘤药物与其他药物对血浆蛋白结合的竞争会改变药物的游离浓度，可能影响其疗效并增加毒性副作用的风险。本研究通过一系列光谱技术，在生理条件下考察了小檗碱（Ber）和姜黄素（Cur）存在时柠檬苦素（limonin）与人血清白蛋白（HSA）的相互作用，以阐明二元和三元体系在分子水平上的结合机制。荧光猝灭实验表明，HSA 与 limonin 的相互作用机制为静态猝灭。通过竞争结合实验，得出 limonin 与 HSA 的结合位点位点 I 的结论，分子对接模拟进一步证实了这一结果。通过热力学数据计算，确定 limonin 通过建立氢键和范德华力与 HSA 形成稳定的配合物。圆二色性（CD）光谱、三维（3D）荧光光谱和同步荧光光谱（SFS）用于验证 limonin 扰动氨基酸微环境并诱导 HSA 构象变化的观点。此外，发现 Ber 或 Cur 的存在进一步改变了原始 HSA-limonin 二元系统相互作用中观察到的变化。体外细胞实验表明，与 HSA 相互作用降低了 limonin 的抗肿瘤活性。相比之下，添加 Ber 或 Cur 增加了肿瘤细胞的抑制率。Ber 和 Cur 的共存显著降低了 limonin 与 HSA 的结合亲和力。本研究增强了对 limonin、Ber、Cur 和 HSA 之间结合特性和相互作用机制的理解。它探索了 HSA 作为多功能药物载体的潜力，并为联合管理策略提供了理论基础。
