荧光及ESI质谱法研究溶菌酶与磷酰化黄酮的相互作用

Study on the Interaction of Lysozyme and Diethyl Flavon-7-yl Phosphate by ESI-MS and Fluorescence Method

分别用荧光法和ESI质谱法研究了磷酰化黄酮和溶菌酶的相互作用 .结果均显示磷酰化黄酮能够和溶菌酶发生弱相互作用 ,与黄酮相比它对溶菌酶更具亲和力 .根据荧光猝灭双倒数图计算了磷酰化黄酮与溶菌酶之间的结合常数为k2 0℃ =1.68× 10 4L/mol,k3 7℃ =1.0 6× 10 4L/mol,实验证明随着温度的升高 ,磷酰化黄酮与溶菌酶的结合常数逐渐降低 ,说明了两者之间形成了复合物 ,此荧光猝灭过程为静态猝灭 .根据F ster能量传递原理计算出磷酰化黄酮在溶菌酶上的结合距离 。

ESI MS and fluorescence methods were used to study the interactions between lysozyme and diethyl flavon 7 yl phosphate and 7 hydroxyflavone. The results showed that the phosphorylated flavonoid could form non covalent complexes lysozyme and showed higher binding affinity with the protein than 7 hydroxyflavone did. The association constants of lysozyme and diethyl flavon 7 yl phosphate were determined from a double reciprocal Lineweaver Burk plot. The binding constants were k 20 ℃ =1.68×10 4 L/mol and k 37 ℃ =1.06×10 4 L/mol respectively. Experiments demonstrated that the higher the temperature was, the lower the slop of quenching curve of lysozyme was in presence of different amounts of diethyl flavon 7 yl phosphate. It was confirmed that the combination of diethyl flavon 7 yl phosphate with lysozyme was a single static quenching process. According to the Fster dipole dipole energy transfer, the distance between the diethyl flavon 7 yl phosphate and tryptophane was measured. From thermodynamical coordination it could be judged that the binding power between diethyl flavon 7 yl phosphate and lysozyme was static electric power.