粉防己碱与牛血清白蛋白相互作用的研究

利用荧光光培和紫外-可见吸收光谱,研究了粉防己碱与BSA相瓦作用的光谱学行为.研究结果表明,粉防己碱埘BSA有较强的荧光猝灭作用,静态猝灭和非辐射能量转移是导致粉防己碱猝火BSA内源荧光的主要原因.利用Stern-Volmer方程处理实验数据,获得了猝火常数Ksv,不同温度下的Ksv分别为1.26×104 L·mol-1(300 K),1.17×104 L·mol-1(310 K),1.12×104 L·mol-1(320 K).根据Forster非辐射能量转移理论计算出了粉防己碱与BSA间的结合距离r(300 K:3.24 nm;310 K:3.31 nm;320 K:3.50nm).此外,还求得了粉防己碱与BSA的结合常数KA(300 K:1.52×105 L·mol-1;310 K:2.03×105 L·mol-1;320 K:2.89×105 L·mol-1)及相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.粉防己碱与BSA相互作用的同步荧光光谱表明,二者的结合对BSA构象产生了影响.

Study on the Interaction of Tetrandrine and Bovine Serum Albumin

The interaction of tetrandrine with bovine serum albumin was studied by fluorescence spectra and ultra-violet spectra. The results showed that tetrandrine could quench the intrinsic fluorescence of BSA. Both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The quenching constants KSV at different temperatures were determined using Stern-Volmer equation. The KSV were 1.26×104 L·mol-1 (300 K), 1.17×104 L·mol-1 (310 K) and 1.12×104 L·mol-1 (320 K). According to the Frster theory of non-radiation energy transfer, the binding distances (r) were 3.24 nm (300 K), 3.31 nm (310 K) and 3.50 nm (320 K). The binding constants (KA) between tetrandrine and BSA (300 K: 1.52×105 L·mol-1; 310 K: 2.03×105 L·mol-1; 320 K: 2.89×105 L·mol-1) and thermodynamic parameters were also obtained. The thermodynamic parameters indicated that the interaction of tetrandrine and BSA was driven mainly by hydrophobic force. Results of synchronous fluorescence spectrum showed that the binding could cause conformational changes of BSA.