吡蚜酮与牛血清白蛋白的相互作用

Interaction Between Pymetrozine and Bovine Serum Albumin

利用紫外吸收、荧光、同步荧光光谱及圆二色谱研究了吡蚜酮与牛血清白蛋白(BSA)的相互作用.结果发现,吡蚜酮使BSA的紫外吸收峰强度降低,峰位红移;BSA的特征荧光峰猝灭,荧光猝灭常数KSV随着温度的升高而降低,表明吡蚜酮与BSA发生了较强的相互作用,且吡蚜酮对BSA的荧光猝灭机制属于静态猝灭.计算了不同温度下的结合常数和结合位点数;由van′tHoff方程计算出体系的ΔH和ΔS值,得出二者之间的作用力主要为氢键和范德华力;根据非辐射能量转移理论确定了给体-受体间的结合距离r=2.4 nm.采用同步荧光光谱和圆二色谱考察了吡蚜酮对牛血清白蛋白构象的影响.

The interaction between pymetrozine （Py） and bovine serum albumin （BSA） was investigated by spectroscopy methods, including fluorescence, ultraviolet absorption （UV） and far-UV circular dichroism （CD） spectroscopies. The quenching mechanism of fluorescence was suggested as static quenching according to the Steru-Volmer equation. The thermodynamic parameters enthalpy change（△H） and entropy change（△S） were calculated, which suggested that the binding power between pymetrozine and bovine serum albumin was hydrogen-bond and van der Waals force. According to the Forster non-radiation energy transfer theory, the binding average distance （ r = 2. 4 nm） between donor （BSA） and acceptor （Py） was obtained. Furthermore, the investigations of the synchromous fluorescence and CD spectra of the system reveal that the conformation of BSA is changed in the presence of Py.