Expression of Bovine Cytokines in Escherichia coli

Abstract

Glutathione S-transferase fusion proteins of bovine interleukin-2 (IL-2), IL-4, IL-6 and interferon-γ (IFN-γ) were expressed in Escherichia coli. Complementary DNA (cDNA) for open reading frame of each cytokine without signal peptide encoding region was amplified by reverse transcriptional polymerase chain reaction method and was subcloned into pGEX-5X-1. In result, IL-6 and IFN-γ fusion proteins in bacteria were soluble, but IL-2 and IL-4 fusion proteins were insoluble. The insoluble IL-2 fusion protein successfully refolded by urea became soluble. The recombinant IL-2, IL-6 and IFN-γ could be obtained by the batch method using Glutathione Sepharose 4B and Factor Xa digestion, which may be useful for preparation of antisera as antigens and functional studies.