Fig. 1

Conventional antibody expression in E. coli. Most of the recombinant antibodies rely on the formation of disulfide bonds in order to reach their native structure. Periplasm is the only E. coli oxidizing compartment compatible with disulfide bond formation and consequently it has been considered the logic environment for antibody accumulation despite its small volume. Mutant strains (gor ⁻/trxB ⁻) with partially oxidizing cytoplasm represent an alternative (cytoplasmic accumulation) as well as expression systems that enable the antibody secretion in the medium or at the cell surface (antibody display)