旋毛虫新生幼虫期特异性T_(314)全长cDNA的克隆及表达

Cloning and Expression of a T_(314) cDNA of Trichinella spiralis

利用 PCR将旋毛虫新生幼虫期特异性全长 T31 4c DNA的信号肽祛除后重组到原核表达载体 p ET- 2 8a。将重组质粒 p ET2 8- T31 4转入克隆菌 DH5α和表达菌 DE3,分别提取质粒进行酶切、测序鉴定。用 IPTG诱导培养重组表达菌DE3,做菌体裂解物外源基因表达产物的 SDS- PAGE分析。将重组质粒表达的融合蛋白免疫家兔制备抗血清 ,采用Western blot检测 T31 4c DNA在旋毛虫不同发育时期的表达情况及其天然表达产物的相对分子质量。测序结果显示 :外源 T31 4c DNA的 PCR产物在重组质粒 p ET2 8- T31 4中阅读框架正确 ;SDS- PAGE分析结果显示 :经 IPTG诱导后转化菌 DE3的裂解产物与对照菌相比出现了 1条相对分子质量约为 390 0 0的新条带 ,大小与外源 c DNA融合蛋白的理论推导值 3880 0相符 ;Western blot检测结果显示 :T31 4c DNA的天然表达产物仅存在旋毛虫新生幼虫 ,不存在于成虫与肌幼虫 ,且相对分子质量大小与其在原核重组质粒中表达产物相同。

The cDNA library of newborn larvae was screened by a probe T 314 . The positive clone contains a cDNA of 1 250 bp in length with an open reading frame (OFR) of 1 014 bp . The cDNA encodes a peptide of 338 amino acid residues. The signal peptide sequence in the N terminal was dispelled by PCR with the primer 1 and primer 2. The recombinant protein was expressed in pET-28a expression system and the potential function of the fusion protein were also analyzed.