恶性疟合成多肽抗原基因在大肠杆菌中表达产物的分离纯化

我们用化学方法合成的两个恶性疟原虫杂合抗原基因，即A基因和B基因〔1.2〕，分别与表达载体pwR450·1重组并转化到大肠杆菌使其表达〔3.4〕。经筛选获得了pwR／A·7和pwR／B·164两个表达较高的克隆菌(经扫描测定表达融合蛋白量分别为菌体总蛋白的8．8％和11．O％)。叉将A基因和B基因串连后与pwR450·l重组并转化到大肠杆菌JMl03株，经筛选鉴定获得了上述两个基因串连的pwR／AB·20克隆菌(表达融合蛋白量为35．8％)。为了进一步研究这3个克隆菌表达蛋白的免疫功能等活性，用8．0mol／L脲处理包涵体，离心沉淀上清液进行DEAE-ephacel柱层析，用Tris梯度缓冲液洗脱，但分离效果不好，而应用PAGE方法进行分离纯化，则可得到电泳纯、稳定又具有免疫原性的产物。

Isolation and Purification of the Fused Protein Encoded by Synthetic Antigen Gene of Plasmodium Falciparum and Its Expression in Escherichia coli

The fusion protein from synthesized plasmodium falciparum hybrid antigen gene expressed in E. colt was purified. The recombinants (pWR/A ?7,pWR/B ?164, pWR/AB ?20)grew in Luria broth medium with lactose. The bacteria were harvested by centrifugation and the pelleted cells were, suspended in lysis buffer containing NP-40 and lysozyme and were treated by sonication and centrifugation. The fusion protein was isolated with SDS-PAGE and recovered by electrophoresis. One to four mg pure fusion protein can be obtained from 80-100 ml bacterial culture media. (Rabbits were immunized by the purified fusion protein and serologic assay has demonstrated with immuno-geneicity).