摘要
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1.521×106L.mol-1,7.048×105L.mol-1,1.473×105L.mol-1,各温度下的最大扩散碰撞猝灭速率常数Kq均大于2.0×1010L.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<7nm,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。
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 rneso-tetra-（4-hydroxyphenyl）-Zn porphyrin and bovine serum albumin were measured under different temperatures. The experiment showed that meso-tetra-（4-hydroxyphenyl）-Zn porphyrin and bovine serum albumin have strong interactions. The binding constants of the reaction at 27 ℃, 35 ℃ and 42 ℃ were 1. 521 × 10^6 L ·mol^-1 , 7. 048 × 10^5 L·mol^-1 and 1. 473 ）〈 10^5 L ·mol^-1 , respectively, and were decreased with increasing the temperature. The constants of maximum diffusion collision quenching rate-Kq were above 2. 0× 10^10 L·mol^-1·s^-1. Therefore, the sort of quenching between meso-tetra-（4-hydroxyphenyl）-Zn porphyrin and bovine serum albumin was determined as static quenching. By the theory of Forster of non-radiation energy transfer, the binding distance and the energy transfer efficiency at 27℃ between meso-tetra-（4-hydroxyphenyl）-Zn porphyrin （accepter of energy） and bovine serum albumin （donor of energy） were obtained, respectively. The binding distance was 3.72 nm, which is less than 7 nm, therefore, the interaction was similar to the non-radiation energy transfer, and the static quenching was further proved. According to the thermodynamic parameters, the main sorts of binding force between meso-tetra-（4- hydroxyphenyl）-Zn porphyrin and bovine serum albumin could be judged as electrostatic force when △G〈0, △H〈0 and/△S〉0.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2009年第3期773-776,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(20577016)
山东省自然科学基金项目(Y2006B36)
山东省自然科学基金项目(Y2008B44)资助
关键词
TPP-Zn
BSA
结合常数
能量转移
荧光猝灭机理
作用力类型
Meso-tetra-（4-hydroxyphenyl）-Zn porphyrin
Bovine serum albumin
Binding constant Non-radiation energy transfer Fluorescence quenching
Sorts of binding force
