State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China.
Luminescence. 2015 Mar;30(2):198-206. doi: 10.1002/bio.2713. Epub 2014 Jun 9.
Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in industrial production, but may have a potential health risk. In this study, the binding characteristics of DEHP with human serum albumin (HSA) in aqueous solution at pH 7.4 were determined using UV/vis absorption, fluorescence, Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD), along with a molecular simulation technique. Analysis of the fluorescence titration data at different temperatures suggested that the fluorescence quenching mechanism of HSA by DEHP was static. The calculated thermodynamic parameters indicated that hydrophobic forces played a predominant role in formation of the DEHP-HSA complex, but hydrogen bonds could not be omitted. Site marker competitive experiments and denaturation studies showed that the binding of DEHP to HSA primarily took place in subdomain IIA of HSA, and molecular docking results further corroborated the binding sites. The synchronous fluorescence, UV/vis absorption, FTIR and CD spectra revealed that the addition of DEHP induced changes in the secondary structure of HSA. Protein surface hydrophobicity (PSH) tests indicated that DEHP binding to HSA caused an increase in the PSH. Moreover, the effects of some metal ions on the binding constant of DEHP - HSA interaction were also investigated.
邻苯二甲酸二（2-乙基己基）酯（DEHP）广泛用作工业生产中的增塑剂，但可能存在潜在的健康风险。在这项研究中，使用紫外/可见吸收、荧光、傅里叶变换红外（FTIR）光谱和圆二色性（CD）以及分子模拟技术，在 pH 7.4 的水溶液中测定了 DEHP 与人血清白蛋白（HSA）的结合特性。不同温度下的荧光滴定数据分析表明，DEHP 对 HSA 的荧光猝灭机制是静态的。计算的热力学参数表明，疏水作用力在 DEHP-HSA 配合物的形成中起主要作用，但氢键不能忽略。位点标记竞争实验和变性研究表明，DEHP 与 HSA 的结合主要发生在 HSA 的亚域 IIA 上，分子对接结果进一步证实了结合位点。同步荧光、紫外/可见吸收、FTIR 和 CD 光谱表明，添加 DEHP 导致 HSA 二级结构发生变化。蛋白质表面疏水性（PSH）测试表明，DEHP 与 HSA 结合导致 PSH 增加。此外，还研究了一些金属离子对 DEHP-HSA 相互作用结合常数的影响。
