防己诺林碱与牛血清白蛋白相互作用的研究

Study on the Interaction between Fangchinoline and Bovine Serum Albumin

在不同温度下,用荧光猝灭光谱、同步荧光光谱和紫外-可见吸收光谱,研究了防己诺林碱与BSA相互作用的光谱学行为。防己诺林碱对BSA有较强的荧光猝灭作用。根据不同温度下防己诺林碱对BSA的荧光猝灭作用,利用Stern-Volmer方程处理实验数据,表明防己诺林碱对BSA的荧光猝灭作用属于静态猝灭。根据F rster非辐射能量转移理论计算出了防己诺林碱与BSA间的结合距离R(27℃2.51 nm;37℃2.72 nm;47℃2.89 nm)、结合常数KA(27℃1.05×105L.mol-1;37℃3.31×105L.mol-1;47℃7.24×105L.mol-1)及对应温度下的热力学参数。热力学数据表明二者主要靠疏水作用力结合,同时用同步荧光光谱探讨了防己诺林碱对BSA构象的影响。

The binding reaction of fangchinoline with bovine serum albumin was studied at different temperatures by fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. It was shown that fangchinoline has a strong ability of quenching the fluorescence of BSA. The Stern-Volmer curve of the fluorescence quenching of BSA by fangchinoline indicated that the quenching mechanism of fangchinoline to BSA was a static quenching. According to the Frrster theory of non--radiation energy transfer, the binding distances （r） at different temperature were 2.51 nm （27℃）, 2. 72 nm （37℃） and 2. 89 nm （47 ℃）, respectively, while the binding constants （KA） were 1.05）〈 10^5·L·mol^-1 （27 ℃）, 3.31）〈 10^5 L·mol^-1 （37 ℃）, and 7.24 ）〈 10^5·L·mol^-1（47 ℃）, respectively. The thermodynamic parameters showed that the interaction of fangchinoline and BSA was mainly driven by hydrophobic force. Synchronous spectrum was used to investigate the conformational changes of BSA.