蚯蚓抗菌肽40 kD Fetidin基因的原核表达与复性

Expression and Renaturation of Antibacterial Peptide 40 kD Fetidin Gene in E.coli

40 kD的fetidin是存在于蚯蚓体腔液中的一种具有较好抗菌活性的蛋白.为了获得大量fe-tidin,从蚯蚓(Eisenia fetida)中调取fetidin的基因,分别克隆到pKW32和pMXB10中,构建了融合和非融合表达载体,并转化大肠杆菌进行诱导表达.结果无论是融合还是非融合表达,产物均以包含体形式存在.融合表达产物通过亲和层析获得复性,复性产物对粘质沙雷氏菌具有抗菌活性.

Fetidin （40 kD） is an antibacterial peptide in earthworm （Eisenia fetida ） coelomic fluid. To obtain a large amount of fetidin, The total RNA of earthworm Eisenia fetida was extracted and DNA fragment of fetidin was got by RT-PCR. The fragment was cloned into pKW32 and pMXB10 vectors respectively. The fusion express vector pKW32-fetidin and non-fusion expression vector pMXBlO-fetidin were constructed, transformed into E. coli and expressed. In despite of fusion expressed product or non-fusion expressed product, the recombinant proteins existed in inclusion bodies. The fusion proteins were renatured by metal affinity chromatography, the recombinant proteins had antibacterial activity against Serratia marcescens.