State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Anal Chim Acta. 2010 Mar 24;663(2):139-46. doi: 10.1016/j.aca.2010.01.053. Epub 2010 Feb 6.
The binding interaction of Alpinetin (APT) with bovine serum albumin (BSA) was studied by fluorescence, UV-visible and synchronous fluorescence spectroscopy (SFS) under simulated physiological conditions. The measured complex spectra were resolved by multivariate curve resolution-alternating least squares (MCR-ALS), yielding a host of data and information, which otherwise would have been impossible to obtain. The extracted profiles corresponded to the spectra of the single species in the APT/BSA mixture. In addition, the presence of the APT-BSA complex was demonstrated, and it was shown that the associated quenching of the fluorescence from the BSA protein resulted from the formation of APT-BSA complex via a static mechanism. The binding constant (K(a(ave))=2.34 x 10(6) L mol(-1)) and the number of sites (n=1) were obtained by fluorescence methods as were the thermodynamic parameters (DeltaH(0), DeltaS(0) and DeltaG(0)). This work suggested that the principal binding between APT to BSA was facilitated by hydrophobic interactions. The thermodynamic parameters for APT were compared to those from the structurally similar Chrysin and Wogonin molecules. It appeared that the entropy parameters were relatively more affected by the small structural changes. SFS from the interaction of BSA and APT showed that the ligand affected the conformation of BSA. The competitive interaction of APT and site makers with BSA indicated site I as the binding area of APT in BSA.
在模拟生理条件下，通过荧光、紫外-可见和同步荧光光谱（SFS）研究了白杨素（APT）与牛血清白蛋白（BSA）的结合相互作用。通过多变量曲线分辨-交替最小二乘法（MCR-ALS）解析测量的复杂光谱，得到了大量的数据和信息，否则这些数据和信息是不可能获得的。提取的轮廓与 APT/BSA 混合物中单种物质的光谱相对应。此外，证明了 APT-BSA 复合物的存在，并且表明 APT-BSA 复合物的形成导致了 BSA 蛋白荧光的猝灭是通过静态机制发生的。荧光法获得了结合常数（K(a(ave))=2.34 x 10(6) L mol(-1))和结合位点数（n=1）以及热力学参数（DeltaH(0)、DeltaS(0)和 DeltaG(0))。这项工作表明，APT 与 BSA 之间的主要结合是通过疏水相互作用促成的。将 APT 的热力学参数与结构相似的白杨黄素和甘草素分子的热力学参数进行了比较。似乎熵参数受较小结构变化的影响相对较大。BSA 与 APT 的相互作用的 SFS 表明，配体影响了 BSA 的构象。APT 和位点标记物与 BSA 的竞争性相互作用表明，位点 I 是 APT 在 BSA 中的结合区域。
