Inclusion bodies: formation and utilisation

The efficient in vivo folding of many heterologous proteins is a major bottleneck of high level production in bacterial hosts and simple optimisation protocols have not been available yet. Therefore, inclusion body (IB) based processes play a major role as a potential strategy for the production of complex recombinant proteins. These processes combine the advantages of a high accumulation of the target protein in well-characterised bacteria such as Escherichia coli, efficient strategies for IB isolation, purification and in vitro protein refolding without the need of complicated coexpression systems. Recent advances in the molecular physiology of IB formation and resolubilisation allow straight-forward optimisation of fermentation processes to obtain a high-quality product. In addition, simple strategies have been developed to optimise the purification and renaturation of disulfide bond containing proteins making a fast transfer of such processes into the industrial production scale realistic.