School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang, Anhui 236037, PR China; State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang, Anhui 236037, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Jul 5;200:51-57. doi: 10.1016/j.saa.2018.04.010. Epub 2018 Apr 6.
Black carbon (BC) is a main component of particulate matter (PM). Due to their small size (<100nm), inhaled ultrafine BC nanoparticles may penetrate the lung alveoli, where they interact with surfactant proteins and lipids, causing more serious damage to human health. Here, BC was analyzed to investigate the binding mechanism of its interaction with protein and induction of cytotoxicity changes. The binding process and protein conformation between BC and a serum protein (bovine serum albumin, BSA) were monitored by using a fluorescence quenching technique and UV-vis absorption, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopies. The experimental results revealed that the fluorescence quenching of BSA induced by BC was a static quenching process and the hydrophobic force played the critical role in the interaction. The native conformation of BSA on the BC surface was slightly disturbed but obvious structural unfolding of the secondary structure did not occur. In the cytotoxicity study, BC nanoparticles with low concentrations exhibited strong toxicity towards BEAS-2B cells. However, the toxicity of BC nanoparticles could be mitigated by the presence of BSA. Therefore, proteins in biological fluids likely reduce the toxic effect of BC on human health. These findings delineated the binding mechanism and the toxicity between BC and the BSA-BC system, contributing to the understanding of the biological effects of BC exposure on human health in polluted atmospheres.
黑碳（BC）是颗粒物（PM）的主要组成部分。由于其粒径小（<100nm），吸入的超细 BC 纳米颗粒可能穿透肺肺泡，在那里与表面活性剂蛋白和脂质相互作用，对人体健康造成更严重的损害。在这里，分析了 BC，以研究其与蛋白质相互作用的结合机制和诱导细胞毒性变化。通过荧光猝灭技术和紫外-可见吸收、傅里叶变换红外（FTIR）和圆二色性（CD）光谱研究了 BC 与血清蛋白（牛血清白蛋白，BSA）之间的结合过程和蛋白质构象。实验结果表明，BSA 被 BC 诱导的荧光猝灭是一个静态猝灭过程，疏水作用力在相互作用中起关键作用。BSA 在 BC 表面的天然构象略有扰动，但二级结构没有明显的结构展开。在细胞毒性研究中，低浓度的 BC 纳米颗粒对 BEAS-2B 细胞表现出很强的毒性。然而，BSA 的存在可以减轻 BC 纳米颗粒的毒性。因此，生物体液中的蛋白质可能会降低 BC 对人体健康的毒性影响。这些发现描绘了 BC 与 BSA-BC 系统之间的结合机制和毒性，有助于理解污染大气中 BC 暴露对人体健康的生物学影响。
