E. coli CyDisCo strain enables a high yield secretion of disulfide bond-containing proteins to the periplasm via Twin-arginine (Tat) pathway. Introducing two exogenous oxidases: the yeast sulfydryl oxidase (Erv1p) and human protein disulfide isomerase (PDI), the CyDisCo strain changes the cytoplasm into an oxidized environment, where the disulfide bonds can efficiently be formed. In this study, we analyzed the proteome changes upon the expression of disulfide bond-containing scFv and the misfolded scFv in the CyDisCo strain. The correctly folded protein is secreted to the periplasm, while the misfolded protein accumulates exclusively in the inclusion body fraction. We observed a high number of significant changes mostly in proteins associated with protein folding and degradation, oxidative stress, membrane transport and integrity.