Production of disulfide-bonded proteins in Escherichia coli.

Disulfide bonds are covalent bonds formed post-translationally by the oxidation of a pair of cysteines. A disulfide bond can serve structural, catalytic, and signaling roles. However, there is an inherent problem to the process of disulfide bond formation: mis-pairing of cysteines can cause misfolding, aggregation and ultimately result in low yields during protein production. Recent developments in the understanding of the mechanisms involved in the formation of disulfide bonds have allowed the research community to engineer and develop methods to produce multi-disulfide-bonded proteins to high yields. This review attempts to highlight the mechanisms responsible for disulfide bond formation in Escherichia coli, both in its native periplasmic compartment in wild-type strains and in the genetically modified cytoplasm of engineered strains. The purpose of this review is to familiarize the researcher with the biological principles involved in the formation of disulfide-bonded proteins with the hope of guiding the scientist in choosing the optimum expression system.