人尿激酶原（pro－urokinase）基因在大肠杆菌中的高效表达

本文用ＰＣＲ方法对人工合成的尿激酶原。ＤＮＡ基因５’端进行改造，将之克隆到表达载体ｐＫＫ２３３－２中，转化大肠杆菌ＪＡ２２１，经ＩＰＴＧ诱导，获得了占总菌体蛋白１５％的高表达。ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔ结果显示表达产物主要为单链尿激酶，并且在菌体内基本上以无活性的包含体形式存在。经体外交复性，从１升培养基中可获得３０００００单位的活性尿激酶原。

High Expression of Human Pro-urokinase Gene in Escherichia coli

Modified by PCR method at the 5' end of the gene, a chemically synthesized pro-urokinase(pro-UK) cDNA gene was eloned into the expression vector pKK 233-2,and was expressed in E.coli JA221 by IPTG induction. The expression level was 15% of total bacterial proteins.Results identified by SDS-PAGE and Western blot showed that the expressed product mainly consisted of the single chain pro-nrokinase,which existed in the form of inactive inclusion bodies.By denaturation find renaturation ac vitro,300000 units of active pro-urokinase were obtained from 1 L culture medium.