贝诺酯与牛血清白蛋白位点选择性结合的分子光谱研究

Abstract

The interaction between benorilate(BEN) and bovine serum albumin(BSA) was investigated under physiological condition by molecular spectroscopic techniques,including fluorescence spectroscopy,UV-visible spectroscopy,synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy.The intrinsic fluorescence of tryptophan in BSA was significantly quenched by BEN via dynamic quenching.The hydrophobic interaction did favor the interaction of BSA with BEN.The apparent binding constants and binding sites number at the tryptophan site were 1 050 L·mol-1 and 0.88,respectively.Thermodynamic parameters such as enthalpy change(ΔH),entropy change(ΔS) and free energy change(ΔG) were also obtained.The conformation changes of BSA in the presence of BEN were proved by the evidences of synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy.Two site-specific fluorescence probes,dansylamide(DA) and dansyl-L-proline(DP),were employed in competitive binding experiments to monitor the BEN binding sites of BSA.The apparent binding constants at siteⅠand Ⅱ were 4 300 and 21 200 L· mol-1,respectively.