[摘要]目的 构建88Arg IL-2的重组克隆，并在大肠杆菌中表达。方法 根据天然IL-2的基因序列设计含目的突变位点的引物，经PCR定点诱变技术获得 88Arg IL-2的重组克隆，插入原核表达质粒pGEX4T-2中，经IPTG诱导在大肠杆菌DH5α中表达88Arg IL-2与GST的融合蛋白。结果所表达的蛋白相对分子质量约为 42 000 。Western blot检测结果表明，该蛋白具有与亲本IL-2相同的抗原性。MTT比色结果表明，88Arg IL-2可促使IL-2依赖细胞株CTLL-2生长，具有与亲本IL-2相近的生物学活性。结论 成功构建了88Arg IL-2的重组克隆，在原核表达系统中高效表达出融合蛋白，并且具有生物学活性。

    [关键词] 白细胞介素2;基因突变;原核表达;蛋白质印迹法;MTT比色法

    CLONING AND PROKARYOTIC EXPRESSION AND ACTIVITY OF88Arg IL-2

    MENG LIN，LIU MING-JUN， WANG BIN， et al

    (Department of Microbiology， Qingdao University Medical College，Qingdao 266021， China)

    [ABSTRACT]ObjectiveTo construct clone of88Arg IL-2 and express it in Escherichia coli. MethodsSite-specific mu-tated primers were designed according to natural IL-2 DNA sequence.88Arg IL-2 gene was amplified using PCR. Then the88Arg IL-2 gene was inserted into expression vector pGEX4T-2 and induced by IPTG to express the protein in E. coli DH5α. ResultsThe molecular weight of fusion protein was 42 000. Western blotting test revealed that it had good specificity to anti-IL-2. The result of MTT assay indicated that88Arg IL-2 could stimulate the proliferation of CTLL-2 which was IL-2-dependent cell strain. Conclusion88Arg IL-2 has been cloned; the fusion protein is expressed in prokaryotic expression system with biologic activity. ......