High cell density cultivation of recombinant Escherichia coli for prodrug of recombinant human GLPs production

Glucagon-like peptide-1 (GLP-1)2 has been attracting increasing interest on account of its prominent benefits in type 2 diabetes. However, its clinical applications are limited by the short half-life in vivo. To overcome this limitation, a new polymer of GLP-1 was developed by prodrug strategy. In this study a recombinant protein, rhGLPs, was successfully constructed, cloned into plasmid pET30a (+) and expressed in Escherichia coli ArcticExpress(DE3)RP in the form of inclusion body. The recombinant fusion protein productivity could be enhanced by high cell density culture of the recombinant strain. As a result, about 40 g wet weight cells per liter were obtained. The protein was purified by size-exclusion chromatography on a Superdex 75 column and refolded using reverse dilution and dialysis methods. SDS–PAGE, HPLC and MALDI-TOF mass spectrometry were undertaken to determine the purity and molecular weight of rhGLPs. Bioactivity assay revealed that it had glucose-lowering and insulin-releasing action in vivo.

► We designed a polymer of recombinant GLP-1 by polymeric prodrug strategy.
► The constructed vector was transformed into different Escherichia coli expression strains.
► We applied dilution and dialysis methods to refold inclusion bodies.
► The high cell density culture of E. coli was used to obtain recombinant proteins.