荧光法研究3-氨基苯硼酸与牛血清白蛋白间的相互作用

为了了解分子印迹反应的机理和最适宜的反应条件, 应用荧光猝灭法研究了3-氨基苯硼酸(APBA)与牛血清白蛋白(BSA)的相互作用, 二者的反应受到体系pH值、离子强度等关键因素的影响. 实验结果表明: 适宜的离子强度和pH值为6.25时, APBA与BSA的色氨酸残基的荧光猝灭反应的物质的量比为2∶1, 表观结合常数K_A＝1.0×10¹¹ L²? mol^－2, 说明二者间形成了较强的化学键. 通过上述研究, 明晰了3-氨基苯硼酸与牛血清白蛋白之间的作用机理, 有助于分离或富集蛋白质中BSA组分, 从而能够改进印迹和洗脱的效率.

Investigations of the Interaction between 3-Aminophenylboronic Acid and Bovine Serum Albumin Using Fluorimetry

In order to understand the chemical mechanism and optimal conditions of the molecular imprinting, the interaction between 3-aminophenylboronic acid (APBA) and bovine serum albumin (BSA) was investigated using fluorescence quenching method with many factors, as the pH value, ionic strength and others, which maybe influence the interaction. The research results indicate that under appropriate ionic strength and pH 6.25, the fluorescence quenching shows that APBA strongly bound with the tryptophan of BSA, and the complex was formed with a molar ratio of 2∶1. Their apparent binding constant is K_A＝1.0×10¹¹ L²?mol^－2, so their chemical bonds between donor BSA and acceptor APBA are relatively strong. According to the results, the interaction mechanism between APBA and BSA is predicted. During following research, it will be entirely possible to separate or enrich BSA composition, maybe it could improve imprinting and eluting efficiency greatly.