Meng Xiaohui, Xia Zhangchen, Cheng Junwen, Wang Yanbin, Ren Xueyong, He Liang, Liu Dan
Key Laboratory of State Forest Food Resources Utilization and Quality Control, Zhejiang Academy of Forestry, Hangzhou 310023, China; Zhejiang Provincial Key Laboratory of Resources Protection and Innovation of Traditional Chinese Medicine, Zhejiang A&F University, Hangzhou 311300, China.
Key Laboratory of State Forest Food Resources Utilization and Quality Control, Zhejiang Academy of Forestry, Hangzhou 310023, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Feb 15;327:125368. doi: 10.1016/j.saa.2024.125368. Epub 2024 Nov 3.
Ergothioneine (EGT) has attracted great attention due to its extremely potent antioxidant properties, universally acknowledged as 'longevity vitamin'. In order to comprehensive understanding of its pharmacodynamics and pharmacokinetics, the binding mechanism of EGT with human serum albumin (HSA) was clarified by cutting-edged multi-spectroscopic approaches and in silico molecular docking coupled with molecular dynamic simulation. Our fluorescence quenching results revealed that the binding of EGT to HSA was in a static quenching mode validated by the descending Stern-Volmer constant (K) values (2.82, 2.36, 1.48 × 10 L mol) and biomolecular quenching rate constant (K) values (2.82, 2.36, 1.48 × 10 L mol) at 298 K, 305 K, and 310 K, respectively. van't Hoff criterion revealed the combination of EGT with HSA was a spontaneous exothermic process (ΔG = -24.16 kJ mol) via hydrogen bonding and van der Waals force interactions (ΔH = -60.25 kJ mol, ΔS = -129.44 J mol K) at 310 K. The analysis of UV-vis absorption spectrum, synchronous fluorescence spectrum, three-dimensional fluorescence spectrum and circular dichroism indicated the addition of EGT affected the microenvironment of Trp214 and rearranged the structure of HSA. The binding replacement assay interpreted their binding site was near the subdomain IIA of HSA (Sudlow's site I), which was intuitively exhibited by molecular docking. In addition of obvious van der Wall forces, attractive charge and Pi-alkyl interactions, the chiral betaine group (N(CH)) in the side chain of EGT was inclined to form hydrogen bonds with Lys199, Ser287 and Arg257 in the hydrophobic cavity of albumin. Moreover, the dynamic simulation reinforced the equilibrium and stability of formed docking complex by four indicators (RMSD, RMSF, Rg, SASA) within 100 ns.
麦角硫因（EGT）因其极强的抗氧化特性而备受关注，它被公认为“长寿维生素”。为了全面了解其药效学和药代动力学，采用前沿的多光谱方法以及计算机模拟分子对接结合分子动力学模拟，阐明了EGT与人血清白蛋白（HSA）的结合机制。我们的荧光猝灭结果表明，EGT与HSA的结合是一种静态猝灭模式，在298K、305K和310K时，通过下降的斯特恩 - 沃尔默常数（K）值（2.82、2.36、1.48×10 L/mol）和双分子猝灭速率常数（K）值（2.82、2.36、1.48×10 L/mol）得到验证。范特霍夫准则表明，在310K时，EGT与HSA的结合是一个自发的放热过程（ΔG = -24.16 kJ/mol），通过氢键和范德华力相互作用（ΔH = -60.25 kJ/mol，ΔS = -129.44 J/mol·K）。紫外 - 可见吸收光谱、同步荧光光谱、三维荧光光谱和圆二色性分析表明，EGT的加入影响了色氨酸214的微环境并重新排列了HSA的结构。结合置换试验表明它们的结合位点靠近HSA的亚结构域IIA（Sudlow位点I），分子对接直观地展示了这一点。除了明显的范德华力、吸引电荷和π - 烷基相互作用外，EGT侧链中的手性甜菜碱基团（N(CH)）倾向于与白蛋白疏水腔内的赖氨酸199、丝氨酸287和精氨酸257形成氢键。此外，动态模拟通过100 ns内的四个指标（RMSD、RMSF、Rg、SASA）加强了形成的对接复合物的平衡和稳定性。
