荧光淬灭和加强理论公式合理性的热力学分析

通过荧光法在不同温度下研究了3种第三代头孢新药: 盐酸头孢吡肟、头孢匹胺和头孢唑肟钠与人血清白蛋白(HSA)和牛血清白蛋白(BSA)的作用, 分别应用荧光淬灭和荧光加强理论公式计算了它们的结合常数等, 进而分别计算了它们的热力学函数. 因对应于不同的理论公式得出的K_A值并不完全相同, 由此得到它们相应的热力学参数也有所不同. 本文对这些热力学数据的差异进行了分析比较, 结果表明: 基于荧光加强理论公式(4)获得的热力学数据显示更为合理. 因而我们建议, 即使在研究受体-底物的荧光淬灭反应时, 采用荧光加强理论公式(4)可以获得更符合实际的结果.

Thermodynamic Analysis of the Reasonableness of the Fluorescence Enhancement and Quenching Theory Equations

The action of the three kinds of the third generation cephalosporin-class new medicine, cefepime hydrochroride, cefpiramide and ceftizoxime, with HSA and BSA was studied at different temperature through fluorescence method. First the binding constants were calculated by using fluorescence quenching and enhancement theoretical equations respectively, then their thermodynamic functions were also calculated respectively. Because the KA corresponding to the different theoretical equations are not completely the same, the thermodynamic parameters calculated from above are different too. In this paper, the difference among these thermodynamic data obtained from the different theoretical equations have been analysed and the result shows that the thermodynamic data, deduced from fluorescence enhancement Eq. (4) are more reasonable. So we propose that even when the fluorescence quenching action of the acceptor-substrate is studied, more conforming to reality results can be obtained by using the fluorescence enhancement Eq. (4).