【摘要】 利用大肠杆菌素释放基因 (kil)能有效地增加细菌外膜通透性促进周质蛋白外泌的原理构建了含kil基因的大肠杆菌外泌表达系统。将大肠杆菌本身的周质分泌蛋白β 内酰胺酶和异源周质分泌蛋白点状产气单胞菌脯氨酰内肽酶作为报告蛋白 ,观察Kil蛋白对这两种通常极少分泌到胞外的周质蛋白胞外分泌的促进作用。我们的研究显示 :kil基因表达时 ,β 内酰胺酶的总活性较对照组提高 1倍 ,胞外分泌活性较对照组提高近 4倍。脯氨酰内肽酶的总活性较对照组提高 0 .8倍 ,胞外分泌活性较对照组提高 3倍更多还原

【Abstract】 An expression release system for heterogeneous proteins in Escherichia coli mediated by the colicin release gene(kil gene) was constructed. The system is based on the ability of the Kil protein to release periplasmic proteins into the growth medium. βlactamase, an E.coli periplasmic protein, and prolyl endopeptidase (PEP), a periplasmic protein of Aeromonas punctata subsp. punctata were used as report proteins. Commonly, these two proteins are seldom released into the growth medium. The results indicated that the released amounts of the βlactamase and of the prolyl endopeptidase were nearly 5 fold and 4 fold than control, respectively.更多还原