荧光光谱法研究四苯基-锌金属卟啉与蛋白质的相互作用机理

利用荧光光度法研究了meso-四(4-羟基苯基)卟啉-锌金属卟啉(TPP-Zn)与牛血清白蛋白(BSA)之间的结合反应。TPP-Zn对于BSA有荧光猝灭作用，基于TPP-Zn对BSA内源荧光的猝灭机理，测定了两者之间在不同温度下的结合常数，温度在27，35和42 ℃时，利用荧光猝灭法测得的结合常数K分别为1.521×106 L·mol-1,7.048×105 L·mol-1,1.473×105 L·mol-1,各温度下的最大扩散碰撞猝灭速率常数K_q均大于2.0×1010 L·mol-1·s-1,由此判定猝灭类型为静态猝灭。根据Frster非辐射能量转移理论，确定了TPP-Zn与BSA之间的能量转移效率E,能量给体(BSA)与受体(TPP-Zn)之间的结合距离r=3.72<7 nm，符合非辐射能量转移条件。依据热力学参数ΔG<0，ΔH<0和ΔS>0确定了TPP-Zn与BSA之间的作用力主要是静电引力。

Study on Interaction Mechanism between Meso-Tetra-(4-Hydroxyphenyl)-Zn Porphyrin and Bovine Serum Albumin by Fluorescence Method

In the present paper,the binding reaction between meso-tetra-(4-hydroxyphenyl)-Zn porphyrin(TPP-Zn) and bovine serum albumin(BSA) was studied at different temperatures by fluorescence method.It was shown that meso-tetra-(4-hydroxyphenyl)-Zn porphyrin has a strong ability of quenching the fluorescence of bovine serum albumin.Based on the mechanisms of fluorescence quenching of bovine serum albumin caused by meso-tetra-(4-hydroxyphenyl)-Zn porphyrin,the binding constants between meso-tetra-(4-hydroxyphenyl)-Z...