Construction of the Prokaryotic Expression Vector for Chicken Interleukin-18 Gene

In this study,specific primers for chicken interleukin 18(ChIL 18) cDNA were designed and synthesized according to the previously reported nucleic acid sequence of chicken interleukin 18 cDNA.The cDNA encoding mChIL 18 was amplified from pMDCh IL 18 Vector with PCR.The recombinant expression plasmid pBV220/mCh IL 18 was constructed by cloning cDNA of mChIL 18 into pBV220 vector and then transformed to E.coli JM109(DE3).Protein was induced by increasing temperature from 30 ℃ to 42 ℃.SDS PAGE analysis showed that the specific protein had a molecular weight approximately 20 000. The sequence of 15 amino acids at the Nterminus of purified protein sequenced by ABI Procise 491 peptide sequencer was the same as that deduced from cDNA sequence of IL 18.