Objectives : to express mpem protein in e . coli 目的：用大肠杆菌表达mpem蛋白。
2.
The fusion protein had expected primary structure . conclusion : pgex - 4t / mpem expression plasmid was constructed . gst / mpem fusion protein was successfully expressed 结论：构建了原核融合表达质粒pgex - 4t mpem ；成功在大肠杆菌中表达gst mpem融合蛋白。
3.
Then it was subjected to hydroxylamine cleavage to verify the predicted primary structure . result : gst / mpem fusion protein was expressed successfully in e . coli . we obtained certain amount of gst / mpem protein by means of affinity chromatography 结果：在大肠杆菌中诱导表达出gst mpem融合蛋白，经过亲和层析获得一定量的gst mpem融合蛋白，它们具有预期正确的一级结构。
4.
Methods : the mouse pem gene ( mpem ) cdna coding sequence was cloned into prokaryotic gst fusion protein expression plasmid pgex - 4t - 3 . the recombinant plasmid was transformed to e . coli bl21 and the gst / mpem fusion protein was induced to express with iptg . the fusion protein was purified by affinity chromatography 方法： pcr扩增小鼠pemcdna编码序列，将它克隆到含有gst的原核表达质粒载体pgex - 4t - 3上，转化大肠杆菌bl21 ，诱导表达gst mpem融合蛋白，通过亲和层析，获得初步纯化的产物，以羟胺切割验证其一级结构。
