Key Laboratory of Marine Eco-Environmental Science and Technology, Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao, 266061, People's Republic of China.
Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), 1 Wenhai Road, Qingdao, 266237, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Feb;28(5):5520-5531. doi: 10.1007/s11356-020-10707-1. Epub 2020 Sep 23.
The binding interaction between emerging pollutant polyvinyl chloride microplastics (PVC MPs) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy, resonance scattering spectroscopy (RLS), UV-visible (UV-vis) absorption spectroscopy, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. Fluorescence results revealed that the fluorescence quenching of BSA induced by PVC MPs was originated from the formation of BSA-PVC complex in static quenching mode. According to Stern-Volmer equation, the binding constants (K) between PVC MPs and BSA at different temperatures were obtained, and the number of binding sites was 1.62. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS), and free energy change (ΔG) were calculated to be - 41.77 kJ mol, 43.17 J mol K, and - 54.63 kJ mol via Van't Hoff equation, indicating electrostatic interaction played a key role in the formation of BSA-PVC complex spontaneously. In addition, the alterations of microenvironment and secondary structure in BSA induced by PVC MPs were further confirmed by synchronous fluorescence spectra, UV-vis, FT-IR, and CD. This work not only provides further information for better understanding the binding interaction of PVC MPs with BSA, but also elucidates the potential biological toxicity of MPs at a molecular level.
在模拟生理条件下，通过荧光光谱法、共振散射光谱法（RLS）、紫外-可见（UV-vis）吸收光谱法、圆二色性（CD）和傅里叶变换红外（FT-IR）光谱法研究了新兴污染物聚氯乙烯微塑料（PVC MPs）与牛血清白蛋白（BSA）之间的结合相互作用。荧光结果表明，PVC MPs 对 BSA 的荧光猝灭源于静态猝灭模式下 BSA-PVC 复合物的形成。根据 Stern-Volmer 方程，在不同温度下获得了 PVC MPs 和 BSA 之间的结合常数（K），并且结合位点的数量为 1.62。通过 Van't Hoff 方程计算得到热力学参数，焓变（ΔH）、熵变（ΔS）和自由能变（ΔG）分别为-41.77 kJ mol、43.17 J mol K 和-54.63 kJ mol，表明静电相互作用在 BSA-PVC 复合物的自发形成中起着关键作用。此外，通过同步荧光光谱、UV-vis、FT-IR 和 CD 进一步证实了 PVC MPs 对 BSA 微环境和二级结构的改变。这项工作不仅为更好地理解 PVC MPs 与 BSA 的结合相互作用提供了进一步的信息，还阐明了 MPs 在分子水平上的潜在生物毒性。
