利福鸟苷（LEF）是一种抗癌药物，与人血清白蛋白（HSA）这种在人体血液中起着载体作用的主要配体进行了生物分子相互作用的研究。研究方法包括生物物理学（荧光、吸收和伏安法）和计算方法（分子对接和分子动力学模拟）。荧光、吸收和伏安法的评估结果证实了LEF与HSA之间的复合物形成。通过LEF与HSA添加量相关的Stern-Volmer常数-温度倒数以及蛋白吸收信号的超光变移，证实了LEF通过静态过程猝灭了HSA的荧光。LEF与HSA的结合强度属于适中（结合常数为2.76-4.77×104 M-1），结合过程主要通过疏水作用、范德华力和氢键驱动，这些结论来源于熵（ΔS=+19.91 J mol-1 K-1）和焓（ΔH=-20.09 kJ mol-1）的变化以及分子对接评估。同时，同步和三维荧光光谱分析验证了LEF与蛋白结合时Trp和Tyr残基周围的微环境波动。LEF与HSA的结合显著抵御了温度引起的蛋白不稳定性。尽管LEF能够与HSA结合在Sudlow的I号和II号位点，但通过竞争性位点标记位移的研究结果表明LEF更倾向于结合在I号位点。分子动力学模拟评估表明，复合物在模拟过程中达到了平衡状态，表现出LEF-HSA复合物的稳定性。这一研究成果由Ramaswamy H. Sarma撰写。

Biomolecular association of an anticancer drug, leflunomide (LEF) with human serum albumin (HSA), the leading ligands carrier in human circulation was characterized using biophysical (i.e., fluorescence, absorption and voltammetric) methods and computational (i.e., molecular docking and molecular dynamics simulation) techniques. Evaluations of fluorescence, absorption and voltammetric findings endorsed the complex formation between LEF and HSA. An inverse relationship of Stern-Volmer constant-temperature and hyperchromic shift of the protein's absorption signal with addition of LEF confirmed the LEF quenched the HSA fluorescence through static process. Moderate nature of binding strength (binding constant = 2.76-4.77 × 104 M-1) was detected towards the LEF-HSA complexation, while the association process was naturally driven via hydrophobic interactions, van der Waals interactions and hydrogen bonds, as evident from changes in entropy (ΔS= + 19.91 J mol-1 K-1) and enthalpy (ΔH = - 20.09 kJ mol-1), and molecular docking assessments. Spectral analyses of synchronous and three-dimensional fluorescence validated microenvironmental fluctuations near Trp and Tyr residues upon LEF binding to the protein. LEF association with HSA significantly defended temperature-induced destabilization of the protein. Although LEF was found to attach to HSA at Sudlow's sites I and II, but exhibited greater preference toward its site I, as detected by the investigations of competitive site-marker displacement. Molecular dynamics simulation assessment revealed that the complex attained equilibrium throughout simulations, showing the LEF-HSA complex constancy.Communicated by Ramaswamy H. Sarma.