FAQ: Will a mammalian glycoprotein be correctly glycosylated and folded if expressed in bacteria?

No, the protein will be expressed without glycans, which may result in a misfolded product since glycoproteins depend on their N-glycans to adopt a stable conformation. Also, other post-translational modifications (such as disulfide bond formation) could be important.

New generation bacterial expression systems like SHuffle® (see Disulfide-Bonded Protein Expression) allow some difficult proteins to be correctly folded and functionally active, even in the absence of N-glycosylation. However, if glycans are essential for protein function or folding, the protein needs to be expressed in a eukaryotic system.