Teaching an old pET new tricks: tuning of inclusion body formation and properties by a mixed feed system in E. coli

• DOI: 10.1007/s00253-017-8641-6
• Publication Date: 2017-11-20T20:45:30Z
• Authors: David J. Wurm; Julian Quehenberger; Julia Mildner; Britta Eggenreich; Christoph Slouka; Andreas Schwaighofer; Karin Wieland; Bernhard Lendl; Vignesh Rajamanickam; Christoph Herwig; Oliver Spadiut
• Keywords: Inclusion Bodies; 0301 basic medicine; Protein Folding; Escherichia coli Proteins; Lactose; Biotechnological Products and Process Engineering; Recombinant Proteins; Culture Media; 3. Good health; 03 medical and health sciences; Glucose; Solubility; Escherichia coli

Against the outdated belief that inclusion bodies (IBs) in Escherichia coli are only inactive aggregates of misfolded protein, and thus should be avoided during recombinant protein production, numerous biopharmaceutically important proteins are currently produced as IBs. To obtain correctly folded, soluble product, IBs have to be processed, namely, harvested, solubilized, and refolded. Several years ago, it was discovered that, depending on cultivation conditions and protein properties, IBs contain partially correctly folded protein structures, which makes IB processing more efficient. Here, we present a method of tailored induction of recombinant protein production in E. coli by a mixed feed system using glucose and lactose and its impact on IB formation. Our method allows tuning of IB amount, IB size, size distribution, and purity, which does not only facilitate IB processing, but is also crucial for potential direct applications of IBs as nanomaterials and biomaterials in regenerative medicine.