Modified penicillin acylase signal peptide allows the periplasmic production of soluble human interferon-γ but not of soluble human interleukin-2 by the Tat pathway in Escherichia coli

Abstract

Production of periplasmic human interferon-gamma (hINF-gamma) and human interleukin-2 (hIL-2) by the Tat translocation pathway in Escherichia coli BL21-SI was evaluated. The expression was obtained using the pEMR vector which contains the Tat-dependent modified penicillin acylase signal peptide (mSPpac) driven by the T7 promoter. The mSPpac-hINF-gamma was processed and the protein was transported to periplasm. Up to 30.1% of hINF-gamma was found in the periplasmic soluble fraction, whereas only 15% of the mSPpac-hIL-2 was processed, but hIL-2 was not found in the periplasmic soluble fraction.

Engineering Microbial Cells for the Biosynthesis of Natural Compounds of Pharmaceutical Significance

“…This is due to the fact that recombinant proteins can easily be transported in and easily released from the periplasmic space by osmotic shock and that there are fewer proteases in the periplasm compared to the cytoplasm. According to this, periplasmic production of human interferon- γ (hINF- γ ) but not of human interleukin-2 (hIL-2) by the Tat (twin arginine translocation) pathway in E. coli strain BL21-SI was described [53]. The Tat system was identified as a transport mechanism for a specific group of periplasmic proteins [54].…”