Abstract

Some proteins will function as flocculants to clear water of suspended particles. Prior work has shown that covalent methylation of a protein’s carboxyl groups can enhance that protein’s flocculant activity; this effect is usually attributed to the reduction in negative charges on the protein. We present results generated using four proteins which show that much of the flocculant activity enhancement occurs in a very short time at the beginning of the methylation reaction, before most of the carboxyl groups have been methylated. A variety of techniques are used to show that the methylation reaction has unintended effects on protein structure and aggregation, and that these effects may play an important role in enhancing protein flocculant activity. The observed enhancement in flocculant activity results from both charge and structural modification.

摘要

一些蛋白质将起到絮凝剂的作用，以清除水中的悬浮颗粒。先前的工作表明，蛋白质羧基的共价甲基化可以增强蛋白质的絮凝活性；这种效应通常归因于蛋白质上负电荷的减少。我们展示了使用四种蛋白质产生的结果，这些结果表明大部分絮凝剂活性增强发生在甲基化反应开始时的非常短的时间内，在大多数羧基被甲基化之前。多种技术被用来表明甲基化反应对蛋白质结构和聚集有意想不到的影响，这些影响可能在增强蛋白质絮凝剂活性方面发挥重要作用。观察到的絮凝剂活性增强是电荷和结构改变的结果。