真核低分子量尿激酶原突变体基因在大肠杆菌中的高效表达

 通过一种融合抗栓肽的低分子量尿激酶原的突变体 (DscuPA 32K)在大肠杆菌中表达的研究 ,进行了一系列不同条件下的实验 .DscuPA 32K在菌株BL2 1中的表达很低 ,表达量仅为 3% ;为提高其表达量 ,引进一种整合稀有tRNA基因的菌株BL2 1 CodonPlusTM RIL ,增加大肠杆菌中识别稀有密码子的tRNA的数量 ,DscuPA 32K的表达水平确实有了很大提高 ,最大表达量约占 2 0 % .结果表明 ,富含稀有密码子的DscuPA 32K在大肠杆菌中表达受限制的因素 ,完全可以由增加稀有tRNA的数量来克服 .免疫印迹分析DscuPA 32K具有良好的抗原性 .此表达菌株可能有利于含大肠杆菌稀有密码子的真核基因在大肠杆菌中的表达 .

High Expression of a Eucaryotic scuPA-32K Mutant Gene in E.coli

The expression of a novel urokinase mutant(DscuPA\|32K) was studied which combined low molecular urokinase and antithrombolytic peptide under a series of different conditions.DscuPA\|32K could not be expressed highly in BL21 strain and the expression amount accounted for 3%.In order to improve the expression level,a novel strain(BL21\|CodonPlus TM \|RIL) carrying gene for the rare codon tRNA was applied to this expression system to increase the amount of rare tRNA.The expression level was indeed improved a lot and the highest expression amount accounted for 20%. These results showed that the limited factors could be overcome by increasing rare codon amount.Western blot analysis revealed that dscuPA 32K had good antigenicity.And the strain could be beneficial to the expression of eucaryotic gene containing E.coli rare codon.