Interactions of perfluorooctanoic acid and perfluorooctanesulfonic acid with serum albumins by native mass spectrometry, fluorescence and molecular docking
Interactions of perfluorooctanoic acid and perfluorooctanesulfonic acid with serum albumins by native mass spectrometry, fluorescence and molecular docking
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通过天然质谱、荧光和分子对接研究全氟辛酸和全氟辛烷磺酸与血清白蛋白的相互作用
DOI：
10.1016/j.chemosphere.2018.01.152
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发表时间：
2018-05-01
期刊：
影响因子：
8.8
通讯作者：
Wang, Xian
中科院分区：
文献类型：
--
作者：
Chi, Quan;Li, Zhixiong;Wang, Xian
采用电喷雾电离质谱(ESI-MS)、荧光、圆二色性(CD)和分子对接(MD)相结合的方法，详细研究和表征了全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)与牛和人血清白蛋白的结合信息。 ESI-MS 分析表明，在高 PFOA/PFOS 摩尔比下，最多有 8 个 PFOA 或 PFOS 分子可以与血清白蛋白结合。通过 ESI-MS 测量结合常数，表明 PFOS 比 PFOA 具有更好的结合亲和力。 PFOA 和 PFOS 可能与不止一个口袋中的血清白蛋白结合。 CD数据表明，PFOA和PFOS的结合可以改变血清白蛋白的构象，降低α螺旋含量，从而可能影响蛋白质的生理功能。 PFOA 和 PFOS 结合引起的蛋白质荧光猝灭现象表明，人血清白蛋白中靠近 Trp 214 的疏水口袋可能是主要的结合位点之一。 MD模拟进一步证实了这一假设。与 ESI-MS 观察一致，根据计算的结合自由能，MD 结果也显示 PFOS 比 PFOA 具有更强的结合亲和力，这可能归因于 PFOS 结合蛋白复合物中多了一个氢键。 (C) 2018 Elsevier Ltd. 保留所有权利。
The binding information of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) with bovine and human serum albumins was investigated and characterized in details by using a combination method of electrospray ionization mass spectrometry (ESI-MS), fluorescence, circular dichroism (CD) and molecular docking (MD). The ESI-MS analysis revealed that maximally eight PFOA or PFOS molecules could bind to serum albumins at high mole ratios of PFOA/PFOS. Association constants were measured by ESI-MS and suggested that PFOS had a better binding affinity than PFOA. PFOA and PFOS were likely to bind with serum albumins in more than one pocket. The CD data demonstrated that binding of PFOA and PFOS could change the conformation of serum albumins with decreasing alpha-helix content, which may affect the protein physiological function. The phenomenon of protein fluorescence quenching by the binding of PFOA and PFOS indicated that the hydrophobic pocket proximate to Trp 214 in human serum albumin might be one of the dominated binding sites. This assumption was further confirmed by MD simulation. Consistent to ESI-MS observation, MD results also displayed a stronger binding affinity of PFOS than PFOA according to the calculated binding free energy, which is probably ascribed to one more hydrogen bond formed in the PFOS-bound protein complexes. (C) 2018 Elsevier Ltd. All rights reserved.