School of Pharmacy, Xuzhou Medical College, Xuzhou, Jiangsu, 221004, China.
Luminescence. 2013 Nov-Dec;28(6):967-72. doi: 10.1002/bio.2469. Epub 2013 Feb 11.
The interaction between fleroxacin (FLX) and pepsin was investigated by spectrofluorimetry. The effects of FLX on pepsin showed that the microenvironment of tryptophan residues and molecular conformation of pepsin were changed based on fluorescence quenching and synchronous fluorescence spectroscopy in combination with three-dimensional fluorescence spectroscopy. Static quenching was suggested and it was proved that the fluorescence quenching of pepsin by FLX was related to the formation of a new complex and a non-radiation energy transfer. The quenching constants KSV , binding constants K and binding sites n were calculated at different temperatures. The molecular interaction distance (r = 6.71) and energy transfer efficiency (E = 0.216) between pepsin and FLX were obtained according to the Forster mechanism of non-radiation energy transfer. Hydrophobic and electrostatic interaction played a major role in FLX-pepsin association. In addition, the hydrophobic interaction and binding free energy were further tested by molecular modeling study.
荧光光谱法研究了氟罗沙星（FLX）与胃蛋白酶之间的相互作用。FLX 对胃蛋白酶的影响表明，基于荧光猝灭和同步荧光光谱法结合三维荧光光谱法，色氨酸残基的微环境和胃蛋白酶的分子构象发生了变化。提出了静态猝灭的观点，并证明了 FLX 对胃蛋白酶的荧光猝灭与新复合物的形成和非辐射能量转移有关。在不同温度下计算了猝灭常数 KSV 、结合常数 K 和结合位点数 n。根据非辐射能量转移的福斯特机制，得到了胃蛋白酶与 FLX 之间的分子相互作用距离（r = 6.71）和能量转移效率（E = 0.216）。FLX-胃蛋白酶结合主要涉及疏水相互作用和静电相互作用。此外，通过分子模拟研究进一步测试了疏水相互作用和结合自由能。
