中文摘要：

目的克隆金黄葡萄球菌表而蛋白凝集因子A（ClfA）活性基因，并进行原核表达。方法以金黄葡萄球菌基因组DNA为模板，采用PCR方法扩增ClfA（221—550）活性基因，克隆入载体pET28a（＋）中，构建重组表达质粒pET28a—ClfA（221—550），转化感受态大肠杆菌BI．21（DE3），IPTG诱导表达，并对表达产物进行SDS—PAGE和Western blot分析。结果PCR扩增出987bp的目的基因片段，重组表达质粒经双酶切证明构建正确。表达产物经SDS—PAGE分析，在相对分子质量约36000处可见目的条带，目的蛋白表达量约占菌体总蛋白的36．76％，且具有良好的反应原性。结论已成功克隆了金黄葡萄球菌ClfA活性基因，并在大肠杆菌BI．21（DE3）中表达了目的蛋白.

英文摘要：

Objective To clone the clumping factor A （ClfA） active gene of Stapylococcus aureus and express in prokaryotic cells. Methods ClfA （221-550） active gene was amplified by PCR using the genomic DNA of Stapylococcus aureus as a template and cloned into vector pET28a （＋）. The constructed recombinant plasmid pET28a-ClfA （221-550） was transformed to competent E.coli BL21 （DE3） for expression under induction of IPTG. The expressed product was identified by SDS-PAGE and Western blot. Results The target gene fragment at a length of 987 bp was amplified by PCR. Restriction analysis proved that recombinant plasmid pET28a- ClfA （221-550） was constructed correctly. The target protein band with a relative molecular mass of about 36 000 was observed on SDS-PAGE profile. The expressed product contained about 36. 76% of total somatic protein and showed good reactogenicity. Conclusion The ClfA active gene of Stapylococcus aureus was successfully cloned and expressed in E. coli BL21 （DE3）.