Bioprocess and Biosystems Engineering

, Volume 35, Issue 1, pp 255–263

Effects of l-arginine on refolding of lysine-tagged human insulin-like growth factor 1 expressed in Escherichia coli


  • Seung Phill Choi
    • Department of Chemical and Biological EngineeringKorea University
  • Yong-Cheol Park
    • Department of Advanced Fermentation Fusion Science and TechnologyKookmin University
  • JungHwa Lee
    • Department of PediatricsKorea University College of Medicine
    • Department of Chemical and Biological EngineeringKorea University
    • Department of Chemical and Biomolecular EngineeringKAIST
Original Paper

DOI: 10.1007/s00449-011-0619-7

Cite this article as:
Choi, S.P., Park, Y., Lee, J. et al. Bioprocess Biosyst Eng (2012) 35: 255. doi:10.1007/s00449-011-0619-7


Insulin-like growth factor 1 (IGF1), a therapeutic protein, is highly homologous to proinsulin in 3-dimensional structure. To highly express IGF1 in recombinant Escherichia coli, IGF1 was engineered to be fused with the 6-lysine tag and ubiquitin at its N-terminus (K6Ub-IGF1). Fed-batch fermentation of E. coli TG1/pAPT-K6Ub-IGF1 resulted in 60.8 g/L of dry cell mass, 18% of which was inclusion bodies composed of K6Ub-IGF1. Subsequent refolding processes were conducted using accumulated inclusion bodies. An environment of 50 mM bicine buffer (pH 8.5), 125 mM l-arginine, and 4 °C was chosen to optimize the refolding of K6Ub-IGF1, and 240 mg/L of denatured K6Ub-IGF1 was refolded with a 32% yield. The positive effect of l-arginine on K6Ub-IGF1 refolding might be ascribed to preventing unfolded K6Ub-IGF1 from undergoing self-aggregation and thus increasing its solubility. The simple dilution refolding, followed by cleavage of the fusion protein by site-specific UBP1 and chromatographic purification of IGF1, led production of authentic IGF1 with 97% purity and an 8.5% purification yield, starting from 500 mg of inclusion bodies composed of K6Ub-IGF1, as verified by various analytical tools, such as RP-HPLC, CD spectroscopy, MALDI-TOF mass spectrometry, and Western blotting. Thus, it was confirmed that l-arginine with an aggregation-protecting ability could be applied to the development of refolding processes for other inclusion body-derived proteins.


Insulin-like growth factor 1Inclusion bodyRefoldingl-arginine

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© Springer-Verlag 2011