The gene clone and expression of extracellular region of the TRAIL / 中国免疫学杂志

ABSTRACT

Objective:To construct the extracellular region of the human TRAIL cDNA expression vector and express and purify the extracellular region of the TRAIL protein. Methods: The mRNA of TRAIL was extracted from CD3 activated normal human PBMC and used as a template for reverse transcription. After PCR amplification, a 730 bp fragment including extracellular region was obtained and cloned into pGEX-2T.The recombinant vector was named pGEX/TRAILex. The pGEX/TRAILex vector was transformed into E.coli DH5a. After IPTIG induced at lower temperature, the collection of the sonicated extract was purified by using the GST agarose 4B. The purified fusion protein was identified by Western blotting with anti-TRAIL McAb.Results:The pGEX/TRAILex was constructed. After IPTG induced,a high level expression of the extracellular region of the TRAIL protein was obtained, SDS-PAGE analysis showed that the recombinant E. coli could express a 54 kD GST fusion protein which accounted for about 28% of the total cellular protein. The study of solubility of expression protein indicated that GST-Tex was expressed predominantly in the soluble form.The purified production was obtained 2.2 mg/L of culture media and the purity of the GST-Tex was more than 95%. GST/TRATLex protein could be recognized by anti-TRAL McAb in Western blot. Conclusion:The expression of recombinant extracellular domain of the human TRAIL protein may be useful for the study of biological functions of TRAIL and it's biotheraphy in tumor.