山萘酚与牛血清白蛋白荧光相互作用研究

Fluorescent Interaction between Kaempferol and Bovine Serum Albumin

目的研究山萘酚(kaem pferol,KF)与牛血清白蛋白(bovine serumal bumin,BSA)相互作用的特征。方法应用荧光光谱法检测KF对BSA内源性荧光的猝灭作用,应用校正的Stern-Volmer方程计算动态荧光猝灭常数和静态猝灭常数,应用荧光猝灭双对数方程计算KF与BSA之间的结合位点数,并且根据热力学参数,推断结合反应的主要作用力类型,在此基础上根据Frster的偶极-偶极非辐射能量转移理论计算KF与BSA结合时供体-受体之间的结合距离和能量转移效率。结果 KF对BSA荧光猝灭机制为静态猝灭和动态猝灭的复合方式,结合常数KA在108数量级,结合位点数接近2,结合距离r=1.45nm,能量转移效率E=0.73,作用力类型为疏水作用。结论 KF可通过动态和静态猝灭结合的机制对BSA的内源性荧光产生明显的猝灭作用,两者之间的结合力为疏水作用。

Objective To study the characteristics of interaction between the kaempferol（KF） and bovine serum albumin（BSA）. Methods The quenching mechanism of the fluorescence of BSA by KF was studied with fluorescence spectra. The dynamic and static quenching constants were determined by the revised Stern-Volmer equation. The number of binding sites was calculated with double logarithmic equation and the main binding force was discussed by thermodynamic equations. The binding distance and energy transfer efficiency between donor（BSA） and acceptor（KF） were obtained based on Frster＇s nonradiative energy transfer theory. Results KF effectively quenched fluorescence of BSA via a combination of static and dynamic quenching processes. The binding constant KA was calculated to be in the order of 108,indicating a strong interaction between KF and BSA. The number of binding site is approximately equal to 2,the binding distance is 1.45 nm,the energy transfer efficiency is 0.73,and the binding force is mainly hydrophobic force. Conclusion KF effectively quenched the intrinsic fluorescence of BSA via combination of static and dynamic quenching mechanism,and the binding is mainly driven by the hydrophobic interaction.