State Key Laboratory of Food Science and Technology, Nanchang University, 235, Nanjing East Road, Nanchang 330047, Jiangxi, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Nov;82(1):424-31. doi: 10.1016/j.saa.2011.07.073. Epub 2011 Jul 27.
The mechanism and conformational changes of farrerol binding to bovine serum albumin (BSA) were studied by spectroscopic methods including fluorescence quenching technique, UV-vis absorption, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that farrerol could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The thermodynamic parameters enthalpy change and entropy change for the binding were calculated to be -29.92 kJ mol(-1) and 5.06 J mol(-1) K(-1) according to the van't Hoff equation, which suggested that the both hydrophobic interactions and hydrogen bonds play major role in the binding of farrerol to BSA. The binding distance r deduced from the efficiency of energy transfer was 3.11 nm for farrerol-BSA system. The displacement experiments of site markers and the results of fluorescence anisotropy showed that warfarin and farrerol shared a common binding site I corresponding to the subdomain IIA of BSA. Furthermore, the studies of synchronous fluorescence, CD and FT-IR spectroscopy showed that the binding of farrerol to BSA induced conformational changes in BSA.
采用荧光猝灭技术、紫外-可见吸收光谱、圆二色光谱和傅里叶变换红外光谱等光谱学方法，在模拟生理条件下研究了法呢醇与牛血清白蛋白（BSA）的结合机制和构象变化。荧光滴定实验结果表明，法呢醇可以通过静态猝灭过程强烈猝灭 BSA 的内源荧光。根据范特霍夫方程计算得到的结合热力学参数焓变和熵变分别为-29.92 kJ mol(-1)和 5.06 J mol(-1) K(-1)，表明法呢醇与 BSA 的结合主要涉及疏水相互作用和氢键。从能量转移效率推断出的法呢醇-BSA 体系的结合距离 r 为 3.11nm。置换实验和荧光各向异性实验结果表明，华法林和法呢醇共享一个结合位点 I，对应于 BSA 的亚结构域 IIA。此外，同步荧光、圆二色和傅里叶变换红外光谱研究表明，法呢醇与 BSA 的结合诱导了 BSA 的构象变化。
