一种蛋白质纯化流程用于提纯大肠杆菌表达的蛋白片段

用一种新的蛋白质纯化流程提纯由大肠杆菌表达的夏氏疟原虫AMA1片段。大肠杆菌表达的片段首先用镍柱提纯，提纯后的蛋白用DTT还原，对盐酸胍透析，再对空气氧化。用RP－HPLC对片段二次提纯，通过冻干转换缓冲液。SDS－PAGE、RP－HPLC和质谱分析都显示，经这种纯化流程提纯的蛋白有很高的纯度，且二硫键已完全正确形成。提示这一蛋白质纯化流程可用于由大肠杆菌表达的低分子量寡二硫键的蛋白。

A Procedure for Purification of Protein Fragments Expressed by Escherichia coli

In order to purify the protein fragment of Plasmodium chabaudi AMA1-B, a kind of new protein purification procedure was employed. The fragment expressed by Escherichia coli was first purified with Ni-NTA resin, then reduced by addition of dithiothreitol, dialyzed against guanidine-HCl and exposed to the air with stirring. After purified using RP-HPLC, the protein buffer was changed into PBS through lyophilization. The SDS-PAGE, RP-HPLC analysis and mass spectrometry analysis used to examine the final purified protein showed that the protein was pure and its disulphide bond was formed completely. The results indicate that this procedure is effective for purification of low molecular weight and low disulphide bonds proteins expressed in E. coli.