Qin Pengfei, Su Baoling, Liu Rutao
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, Jinan 250100, PR China.
Mol Biosyst. 2012 Apr;8(4):1222-9. doi: 10.1039/c2mb05423j. Epub 2012 Jan 31.
Ciprofloxacin (CPFX) and enrofloxacin (ENFX) are two of the most widely used fluoroquinolones (FQs) in human and veterinary medicines. Their occurrence in the environment has received much attention because of the potential adverse effects on humans and ecosystem functions. In this paper, we investigated the interaction mechanism between the two FQs and lysozyme by the spectroscopic and molecular docking methods. As shown by the fluorescence spectroscopy, additions of CPFX or ENFX effectively quenched the intrinsic fluorescence of lysozyme, which was attributed to the formation of a moderately strong complex. The enthalpy change (ΔH) and entropy change (ΔS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of two FQs to lysozyme. Furthermore, data obtained by UV-vis absorption, synchronous fluorescence and circular dichroism (CD) suggested that both CPFX and ENFX could lead to the conformational and some microenvironmental changes of lysozyme. Finally, the molecular docking illustrated that the two FQs had specific interactions with the residues of Trp62 and Trp63.
环丙沙星（CPFX）和恩诺沙星（ENFX）是人类和兽用药物中使用最广泛的两种氟喹诺酮类药物（FQs）。由于它们对人类和生态系统功能存在潜在不利影响，其在环境中的出现受到了广泛关注。在本文中，我们通过光谱学和分子对接方法研究了这两种氟喹诺酮类药物与溶菌酶之间的相互作用机制。荧光光谱结果表明，添加CPFX或ENFX可有效猝灭溶菌酶的固有荧光，这归因于形成了中等强度的复合物。焓变（ΔH）和熵变（ΔS）表明，范德华力和氢键是两种氟喹诺酮类药物与溶菌酶结合过程中的主要分子间作用力。此外，紫外可见吸收光谱、同步荧光光谱和圆二色光谱（CD）数据表明，CPFX和ENFX均可导致溶菌酶的构象和一些微环境变化。最后，分子对接表明这两种氟喹诺酮类药物与色氨酸62（Trp62）和色氨酸63（Trp63）残基存在特异性相互作用。
