A water-soluble DsbB variant that catalyzes disulfide-bond formation in vivo

Nat Chem Biol. 2017 Sep;13(9):1022-1028. doi: 10.1038/nchembio.2409. Epub 2017 Jun 19.


Escherichia coli DsbB is a transmembrane enzyme that catalyzes the reoxidation of the periplasmic oxidase DsbA by ubiquinone. Here, we sought to convert membrane-bound DsbB into a water-soluble biocatalyst by leveraging a previously described method for in vivo solubilization of integral membrane proteins (IMPs). When solubilized DsbB variants were coexpressed with an export-defective copy of DsbA in the cytoplasm of wild-type E. coli cells, artificial oxidation pathways were created that efficiently catalyzed de novo disulfide-bond formation in a range of substrate proteins, in a manner dependent on both DsbA and quinone. Hence, DsbB solubilization was achieved with preservation of both catalytic activity and substrate specificity. Moreover, given the generality of the solubilization technique, the results presented here should pave the way to unlocking the biocatalytic potential of other membrane-bound enzymes whose utility has been limited by poor stability of IMPs outside of their native lipid-bilayer context.

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Catalysis
  • Disulfides / chemistry*
  • Genetic Variation
  • Membrane Proteins / chemistry*
  • Membrane Proteins / genetics
  • Models, Biological
  • Protein Engineering
  • Protein Folding
  • Solubility
  • Water / chemistry*


  • Bacterial Proteins
  • Disulfides
  • DsbB protein, Bacteria
  • Membrane Proteins
  • Water