To understand the effect of 17α-ethinylestradiol (EE2) on the conformation changes of bovine serum albumin (BSA), the binding mechanisms of EE2 with BSA were investigated by fluorescence spectroscopy, time-resolved fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, UV–visible spectroscopy, circular dichroism (CD) spectroscopy and molecular docking. The quenching constants, binding constants, the number of binding sites, thermodynamic parameters, binding distance and the secondary structure changes of BSA were determined. The results of fluorescence quenching experiment suggested that the fluorescence quenching of BSA by EE was due to the formation of complex through static quenching, which was also confirmed by time-resolved fluorescence measurements. The thermodynamic parameters indicated that the binding of EE2 to BSA was driven mainly by van der Waals forces and hydrogen bonding. The conformation alterations of BSA upon EE2 binding were studied by UV–vis spectroscopy and CD spectroscopy. The results of site marker competitive experiments and molecular docking showed that the binding sites of EE2 were mainly located within site I in the subdomain IIA of BSA.

为了解17α-炔雌醇（EE2）对牛血清白蛋白（BSA）构象变化的影响，通过荧光光谱，时间分辨荧光光谱，同步荧光光谱，三维荧光研究了EE2与BSA的结合机理。光谱，紫外可见光谱，圆二色性（CD）光谱和分子对接。测定了BSA的猝灭常数，结合常数，结合位点数，热力学参数，结合距离和二级结构变化。荧光猝灭实验的结果表明，EE对BSA的荧光猝灭是由于通过静态猝灭形成络合物所致，这也通过时间分辨荧光测量得到了证实。热力学参数表明，EE2与BSA的结合主要由范德华力和氢键驱动。通过紫外可见光谱和CD光谱研究了BS2在EE2结合后的构象变化。位点标记竞争实验和分子对接的结果表明，EE2的结合位点主要位于BSA的IIA亚域的I位。