Pan Hongshuo, Wu Xinjie, Han Ruyue, He Shuhao, Li Nianhe, Yan Hui, Chen Xinyun, Zhu Ziyu, Du Zhongyu, Wang Hao, Xu Xiangyu
Laboratory of New Antitumor Drug Molecular Design & Synthesis, College of Basic Medicine, Jining Medical University, Jining 272067, Shandong Province, China.
State Key Laboratory for Macromolecule Drugs and Large-scale Manufacturing, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252059, Shandong Province, China.
Int J Biol Macromol. 2025 Jan;284(Pt 1):138126. doi: 10.1016/j.ijbiomac.2024.138126. Epub 2024 Nov 26.
Graphene oxide‑gold nanocomposites (GO-AuNCPs) are promising candidates in nanomedicine. They will inevitably bind with biomolecules such as serum albumin (SA) in the body while they enter the organism. The interaction between GO-AuNCPs and human serum albumin (HSA)/bovine serum albumin (BSA) were investigated by using multispectroscopic methods, elucidating the binding principles through molecular simulations. The results of ultraviolet-visible (UV-vis) absorption spectroscopy and steady-state fluorescence spectroscopy indicated that GO-AuNCPs interacted with HSA/BSA with different degrees of interaction. The binding of GO-AuNCPs and HSA/BSA was a spontaneous endothermic reaction, and the quenching mechanism is static quenching. The binding constant (K) value of BSA binding to GO-AuNCPs at the same temperature was greater than that for HSA, indicating a stronger affinity of BSA for GO-AuNCPs. Molecular simulation revealed that the binding sites of GO-AuNCPs on HSA/BSA were located within the slits of the subdomains IB and IIIA, rather than within any known binding regions. This significant finding was validated by using of site markers phenylbutazone (PB) and flufenamic acid (FA). Synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, and circular dichroism (CD) spectroscopy showed that the conformation of HSA/BSA was altered upon the addition of GO-AuNCPs, resulting in slight structural changes of tryptophan and tyrosine residues. Although the secondary structure of HSA/BSA was changed, the α-helix remained dominant. The results provide a theoretical and experimental foundation for developing of safe and effective nanomaterials, which is of great theoretical significance.
氧化石墨烯-金纳米复合材料（GO-AuNCPs）是纳米医学领域中很有前景的候选材料。它们进入机体后，不可避免地会与体内的生物分子如血清白蛋白（SA）结合。采用多光谱方法研究了GO-AuNCPs与人类血清白蛋白（HSA）/牛血清白蛋白（BSA）之间的相互作用，并通过分子模拟阐明了结合原理。紫外可见（UV-vis）吸收光谱和稳态荧光光谱结果表明，GO-AuNCPs与HSA/BSA存在不同程度的相互作用。GO-AuNCPs与HSA/BSA的结合是一个自发的吸热反应，猝灭机制为静态猝灭。相同温度下，BSA与GO-AuNCPs的结合常数（K）值大于HSA，表明BSA对GO-AuNCPs的亲和力更强。分子模拟显示，GO-AuNCPs在HSA/BSA上的结合位点位于亚结构域IB和IIIA的裂隙内，而非任何已知的结合区域。使用位点标记物苯基丁氮酮（PB）和氟芬那酸（FA）验证了这一重要发现。同步荧光光谱、三维荧光光谱和圆二色（CD）光谱表明，加入GO-AuNCPs后HSA/BSA的构象发生改变，导致色氨酸和酪氨酸残基的结构略有变化。虽然HSA/BSA的二级结构发生了变化，但α-螺旋仍占主导地位。这些结果为开发安全有效的纳米材料提供了理论和实验基础，具有重要的理论意义。
