目的 :选择合适的载体系统用于CS3菌毛的高水平表达和装配。方法 :将CS3操纵子基因分别克隆入pUC19,pTrc99A等载体中 ,采用全细胞ELISA方法检测CS3菌毛的表达水平 ,并用SDS PAGE和电子显微镜技术证实菌毛的表达和组装。结果 :CS3菌毛在质粒pUC19中的表达水平明显高于在pTrc99A和pBR32 2中的表达水平 ,基因的插入方向对表达影响甚微 ;SDS PAGE可看到表达条带 ,电镜下可观察到菌毛形成。结论 :CS3自身的启动子在表达中起决定作用 ,质粒拷贝数是影响表达水平的关键因素 Purpose: Choose a suitable vector system for high level expression and assembly of CS3 pilus. METHODS: CS3 operon gene was cloned into pUC19 and pTrc99A vector respectively. The expression of CS3 pili was detected by whole cell ELISA. The expression and assembly of pili were confirmed by SDS PAGE and electron microscopy. Results: The expression level of CS3 pili in plasmid pUC19 was significantly higher than that in pTrc99A and pBR32 2, and the direction of gene insertion had little effect on the expression. SDS-PAGE showed that the expression bands were observed under electron microscope Hair formation. Conclusion: The promoter of CS3 plays a decisive role in the expression, and plasmid copy number is the key factor affecting the expression level