Expression and purification of recombinant human interferon-gamma produced by Escherichia coli = 대장균이 생산한 재조합 인체 감마인터페론의 발현과 정제

Abstract

For the production of the recombinant human interferon-gamma (rhIFN-γ) in Escherichia coli, human glucagon and ferritin heavy chain were used as fusion partners. Even though rhIFN-γ is expressed as an inclusion body form in E. coli because of strong hydrophobicity of itself, over 50% of fused rhIFN-γ was expressed as soluble form in E. coli OrigamiTM (DE3) harboring pT7FH(HE)-IFN-γ which encodes ferritin heavy chain-fused rhIFN-γ. In the case of using glucagon-ferritin heavy chain hybrid mutant as a fusion partner, 6X His-tag was additionally introduced to N-terminus of GFHM(HE)-IFN-γ for enhancing purification yields of rhIFN-γ. Fusion protein HGFHM(HE)-IFN-γ with two 6X His-tag was more effectively bound to Ni-NTA agarose bead than GFHM(HE)-IFN-γ with a 6X His-tag. rhIFN-γ was completely purified from enterokinase-treated HGFHM(HE)-IFN-γ by Ni-NTA affinity column. For high-level production of rhIFN-γ, glucose was used as the sole carbon source with simple exponential feeding rate (2.4~7.2 g/h) in fed-batch process. The effective lactose concentration for the expression of the rhIFN-γ was 10~20 mM. Under the fed-batch culture conditions, rhIFN-γ production yield reached 11 g DCW/L for 6 hours after lactose induction.