人IL—2cDNA的亚克隆及其在大肠杆菌中的高效表达

目的构建重组人IL－2表达质粒并观察其在大肠杆菌中的表达效率。方法应用重组DNA技术，将人IL一2cDNA亚克隆于pKK223－3表达载体，构建成pKK223－3－IL－2重组表达质粒，转化JM105受体菌后得到工程菌，命名为JM105／PKK223－3－IL－2。结果凝胶电泳和核酸杂交证实，人IL一2cDNA已成功地插入到pKK223－3质位的EcoRI－HindIII位点。在异丙基硫代-β-D-半乳糖昔（IPTG）诱导下，工程菌中重组人IL－2表达效率为26％；诱导8h，IL－2的产量达峰值；用含TritonX100的缓冲液反复洗涤，获得纯度很高的包含体。结论人IL-2cDNA在tac启动子控制不能在大肠杆菌中高效地表达人IL-2。

Subcloning of human IL-2 cDNA and its high expression in E.coli

Objective To construct the expressing plasmid of recombinant human interleukin- 2 (IL-2) and observe its expressing efficiency in E. coli. Methods Human IL - 2cDNA was subcloned intopKK223 - 3 expressing vector using recombinant DNA technique, Engineered bacterial strain wasobtained by transforming E. coli JM105 with ednant plasrnd., name for JM105/pKK223 - 3 - IL- 2. Results Gel electrophoresis and nucleic acid hybridization sbe that IL - 2cDNA had insertedinto EcoRI - HindIII site in pKK223 - 3 plasmid. The expression effciiency of IL - 2 was 26% usingIPTG an inducer. The output of IL - 2 increased to the - after inducing 8 hours . The purity ofthe inclusion from the expressing bacterial stran was vew high with Triton X100 washing agin andagain. Conlusions Recombinant humnan IL - 2 was effcienly exped with tac promoter in E. coli.