离子液体与蛋白质相互作用的荧光光谱研究

在25,35和45℃测定了离子液体(C4mim]Br,C6mim]Br,C8mim]Br)对蛋白质(BSA、溶菌酶)的荧光猝灭光谱,分析了离子液体与蛋白质相互作用的荧光猝灭规律,计算了荧光猝灭过程的猝灭常数和热力学参数.结果表明:离子液体可以有规律地使蛋白质的荧光猝灭,猝灭是由离子液体与蛋白质的碰撞引起的,是一个动态猝灭过程.该过程的猝灭常数很小,说明离子液体与蛋白质之间的相互作用较弱.热力学研究表明,猝灭过程是一个熵驱动过程,疏水相互作用是其主要特征.

A Fluorescence Spectroscopy Study on the Interactions Between Ionic Liquids and Proteins

In this paper,the interactions between ionic liquids ( Cnmim]Br(n=4,6,8)and proteins (BSA,lysozyme) are studied using fluorescence spectra at 25,35 and 45 ℃. The mechanism of the fluorescence quench is investigated,and the binding constants and the thermodynamic parameters for the interactions are obtained. It is shown that the fluorescence of proteins is quenched regularly by addition of the ionic liquids. The quenching of fluorescence is a dynamic process caused by the collision of ionic liquids with proteins. The small binding constants indicate the weak interactions between ionic liquids and proteins. The thermodynamic parameters suggest that the quenching process is controlled by entropy with the characteristic of hydrophobic interaction.