摘要
目的 实现铜绿假单胞菌外毒素A(PEA)全基因的可溶性表达。方法 用基因重组技术构建pMAL PEA原核分泌型表达载体 ,并在大肠杆菌BL2 1中进行表达 ,然后利用直链淀粉树脂对表达蛋白进行亲和层析纯化。结果 酶切鉴定及测序结果表明pMAL P2X载体上成功地插入了PEA全基因。用IPTG诱导目的基因表达 ,表达的融合蛋白量约占细菌总蛋白的 2 0 %。表达产物经超声处理后 ,80 %的融合蛋白存在于上清液中 ,说明实现了PEA的可溶性表达。表达的融合蛋白经亲和层析纯化后进行SDS PAGE电泳 ,显示为一条蛋白带 ,分子量约为 112kD。结论 成功地对PEA全基因进行了可溶性表达和纯化 ,获得了稳定表达的工程菌 ,为深入研究PEA的致病机制和制备用于免疫导向治疗的重组毒素奠定了基础。
Objective To clone and to express the full-length Pseudomonas aeruginosa exotoxin A gene and to purify the expressed protein using affinity chromatography. Methods Exotoxin A gene was amplified from the recombinant plasmid pSK/PEA-T vector and subcloned into the pMAL-P2X vector. Then the recombinant plasmid pMAL- PEA was transformed to E.coli BL21. After induction with IPTG, the expressed protein was analyzed by SDS-PAGE and purified with affinity chromatography. Results The recombinants expressed the fusion protein at a level of about 20% of total cell proteins, and 80% of the fusion protein was secreted into the supernatant. Conclusion Successful expression and purification of PEA are of significance for in-depth study of the pathogenic mechanism of Pseudomonas aeruginosa and preparing immunotoxin.
出处
《解放军医学杂志》
CAS
CSCD
北大核心
2004年第2期156-158,共3页
Medical Journal of Chinese People's Liberation Army
基金
全军医学科研"十五"计划青年基金项目资助课题 (编号 0 1Q1 0 8)
关键词
铜绿假单胞菌
外毒素A
重组质粒
基因表达
Pseudomonas aeruginosa
exotoxin A
recombinant plasmid
gene expression
