电导法研究表面活性剂与蛋白质的相互作用

STUDY OF CONDUCTIVITY CHANGES OF INTERACTIONS BETWEEN SURFACTANTS AND PROTEINS

较系统地研究了溶液中离子型表面活性剂与蛋白质相互作用时电导率的变化，并根据实验现象得出表面活性剂与蛋白质作用的两种模式－ 疏水作用模式和电荷作用模式。表面活性剂采用疏水作用模式与蛋白质结合时，蛋白质的二硫键逐一断裂，三级结构逐渐打开，电导率曲线出现一些小“平台”；采用电荷作用模式吸附蛋白质时，首先形成疏水复合体，产生白色浑浊，随离子型表面活性剂浓度的增加，疏水复合体转变成亲水复合体，白色浑浊完全溶解。在有的体系中，两种作用并不是界限分明，它们可以同时表现出来。

The surfactant-protein interaction was studied by conductometer in this work. According to experimental results, two models of the interactions between surfactants and proteins were deduced. One is hydrophobic interaction model; the other is electrostatic force model. When surfactant was bound to proteins by hydrophobic interaction,protein's disulfide bonds were braken down one by one, so the ternary structure of proteins was opened step by step and some little terraces appear on conductivity curve. While surfactant was bound to proteins by electrostatic force, a kind of white hydrophobic complex was formed, and the solution became turbid. By increasing the concentration of ionic surfactants, the hydrophobic complex substance became hydrophilic. And the white turbid disappeared. However, in some systems, two kinds of bindings could be found simultaneusly. These results are helpful to understand the emulsification caused by proteins and its de-emulsification.