Proteins that are not naturally secreted may be oxidized and misfolded on their way through the periplasm during M13 phage display. We have demonstrated that cytosolic proteins may also be functionally displayed on M13 phage by using a DsbA- E.coli cell and a signal peptide that directs the target protein to the SRP pathway.
A novel M13 phage display method: An engineered E.coli combined with SRP-dependent protein targeting
Chen, M. and Samuelson J.C. (2016) A DsbA-deficient Periplasm Enables Functional Display of a Protein with Redox-Sensitive Folding on M13 Phage. Biochemistry PMID: 27210801