Abstract: First of all, the gene of human Ifn-ε was synthesized, the expression vectors of Ifn-ε/pET-21a(+) and Ifn-ε/pET-22b(+) were constructed respectively after codon optimization. The expression vector was transformed into Escherichia coli and the expression conditions were further optimized. Two dominant strains Ifn-ε/pET-21a/BL21A and Ifn-ε/pET-22b/BL21A were obtained. At last, IFN-ε with high purity was isolated from Ifn-ε/pET-22b/BL21A throgh fermentation, extraction, purification, and its structure was confirmed by mass spectrometry. An effective expression system of human IFN-ε has been established to provide large quantity of protein for the study of its structure and mechanism. Moreover, the establishment of expression system through gene synthesis laid the foundation for the study of structure-activity relationship by amino acid mutation.

Key words: interferon epsilon, gene synthesis, codon optimization, prokaryotic expression, mass spectrometry