Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

A monodisperse transmembrane α-helical peptide barrel

Abstract

The fabrication of monodisperse transmembrane barrels formed from short synthetic peptides has not been demonstrated previously. This is in part because of the complexity of the interactions between peptides and lipids within the hydrophobic environment of a membrane. Here we report the formation of a transmembrane pore through the self-assembly of 35 amino acid α-helical peptides. The design of the peptides is based on the C-terminal D4 domain of the Escherichia coli polysaccharide transporter Wza. By using single-channel current recording, we define discrete assembly intermediates and show that the pore is most probably a helix barrel that contains eight D4 peptides arranged in parallel. We also show that the peptide pore is functional and capable of conducting ions and binding blockers. Such α-helix barrels engineered from peptides could find applications in nanopore technologies such as single-molecule sensing and nucleic-acid sequencing.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Structure of E. coli Wza, peptide design and electrical properties of the cWza pore.
Figure 2: Electrical properties of mutant cWza pores.
Figure 3: Interaction of cWza peptide pores with cationic CDs.
Figure 4: Orientation and stoichiometry of the cWza-Y373C pore.
Figure 5: CD-templated barrel and its electrical properties.
Figure 6: Model for membrane insertion and pore formation by cWza peptides.

Similar content being viewed by others

Accession codes

Accessions

Protein Data Bank

References

  1. Woolfson, D. N. The design of coiled-coil structures and assemblies. Adv. Protein Chem. 70, 79–112 (2005).

    CAS  PubMed  Google Scholar 

  2. Woolfson, D. N. et al. De novo protein design: how do we expand into the universe of possible protein structures? Curr. Opin. Struct. Biol. 33, 16–26 (2015).

    CAS  PubMed  Google Scholar 

  3. Woolfson, D. N., Bartlett, G. J., Bruning, M. & Thomson, A. R. New currency for old rope: from coiled-coil assemblies to alpha-helical barrels. Curr. Opin. Struct. Biol. 22, 432–441 (2012).

    CAS  PubMed  Google Scholar 

  4. Lear, J. D., Wasserman, Z. R. & DeGrado, W. F. Synthetic amphiphilic peptide models for protein ion channels. Science 240, 1177–1181 (1988).

    CAS  PubMed  Google Scholar 

  5. Joh, N. H. et al. De novo design of a transmembrane Zn2+-transporting four-helix bundle. Science 346, 1520–1524 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  6. Franceschini, L., Soskine, M., Biesemans, A. & Maglia, G. A nanopore machine promotes the vectorial transport of DNA across membranes. Nat. Commun. 4, 2415 (2013).

    PubMed  PubMed Central  Google Scholar 

  7. Bayley, H. Membrane-protein structure: piercing insights. Nature 459, 651–652 (2009).

    CAS  PubMed  Google Scholar 

  8. Dong, C. et al. Wza the translocon for E. coli capsular polysaccharides defines a new class of membrane protein. Nature 444, 226–229 (2006).

    Article  CAS  Google Scholar 

  9. Kong, L. et al. Single-molecule interrogation of a bacterial sugar transporter allows the discovery of an extracellular inhibitor. Nat. Chem. 5, 651–659 (2013).

    CAS  PubMed  Google Scholar 

  10. Soskine, M. et al. An engineered ClyA nanopore detects folded target proteins by selective external association and pore entry. Nano Lett. 12, 4895–4900 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  11. Soskine, M., Biesemans, A., De Maeyer, M. & Maglia, G. Tuning the size and properties of ClyA nanopores assisted by directed evolution. J. Am. Chem. Soc. 135, 13456–13463 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  12. Tanaka, K., Caaveiro, J. M., Morante, K., González-Mañas, J. M. & Tsumoto, K. Structural basis for self-assembly of a cytolytic pore lined by protein and lipid. Nat. Commun. 6, 6337 (2015).

    PubMed  PubMed Central  Google Scholar 

  13. Zaccai, N. R. et al. A de novo peptide hexamer with a mutable channel. Nat. Chem. Biol. 7, 935–941 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  14. Thomson, A. R. et al. Computational design of water-soluble alpha-helical barrels. Science 346, 485–488 (2014).

    CAS  PubMed  Google Scholar 

  15. Bayley, H. Designed membrane channels and pores. Curr. Opin. Biotechnol. 10, 94–103 (1999).

    CAS  PubMed  Google Scholar 

  16. Bayley, H. & Jayasinghe, L. Functional engineered channels and pores (Review). Mol. Membr. Biol. 21, 209–220 (2004).

    CAS  PubMed  Google Scholar 

  17. Majd, S. et al. Applications of biological pores in nanomedicine, sensing, and nanoelectronics. Curr. Opin. Biotechnol. 21, 439–476 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  18. Braha, O. et al. Designed protein pores as components for biosensors. Chem. Biol. 4, 497–505 (1997).

    CAS  PubMed  Google Scholar 

  19. Bayley, H. & Cremer, P. S. Stochastic sensors inspired by biology. Nature 413, 226–230 (2001).

    CAS  PubMed  Google Scholar 

  20. Bayley, H. Nanopore sequencing: from imagination to reality. Clin. Chem. 61, 25–31 (2015).

    CAS  PubMed  Google Scholar 

  21. Jain, M. et al. Improved data analysis for the MinION nanopore sequencer. Nat. Methods 12, 351–356 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  22. Song, L. et al. Structure of staphylococcal alpha-hemolysin, a heptameric transmembrane pore. Science 274, 1859–1866 (1996).

    CAS  PubMed  Google Scholar 

  23. Gu, L. Q., Braha, O., Conlan, S., Cheley, S. & Bayley, H. Stochastic sensing of organic analytes by a pore-forming protein containing a molecular adapter. Nature 398, 686–690 (1999).

    CAS  PubMed  Google Scholar 

  24. Banerjee, A. et al. Molecular bases of cyclodextrin adapter interactions with engineered protein nanopores. Proc. Natl Acad. Sci. USA 107, 8165–8170 (2010).

    CAS  Google Scholar 

  25. Walshaw, J. & Woolfson, D. N. Socket: a program for identifying and analysing coiled-coil motifs within protein structures. J. Mol. Biol. 307, 1427–1450 (2001).

    CAS  PubMed  Google Scholar 

  26. van den Berg, B., Prathyusha Bhamidimarri, S., Dahyabhai Prajapati, J., Kleinekathöfer, U. & Winterhalter, M. Outer-membrane translocation of bulky small molecules by passive diffusion. Proc. Natl Acad. Sci. USA 112, E2991–E2999 (2015).

    CAS  PubMed  Google Scholar 

  27. Doyle, D. A. et al. The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science 280, 69–77 (1998).

    CAS  PubMed  Google Scholar 

  28. Mueller, M., Grauschopf, U., Maier, T., Glockshuber, R. & Ban, N. The structure of a cytolytic alpha-helical toxin pore reveals its assembly mechanism. Nature 459, 726–730 (2009).

    CAS  PubMed  Google Scholar 

  29. Miles, G., Movileanu, L. & Bayley, H. Subunit composition of a bicomponent toxin: staphylococcal leukocidin forms an octameric transmembrane pore. Protein Sci. 11, 894–902 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  30. Smart, O. S., Breed, J., Smith, G. R. & Sansom, M. S. A novel method for structure-based prediction of ion channel conductance properties. Biophys. J. 72, 1109–1126 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Sukharev, S., Betanzos, M., Chiang, C. S. & Guy, H. R. The gating mechanism of the large mechanosensitive channel MscL. Nature 409, 720–724 (2001).

    CAS  PubMed  Google Scholar 

  32. Wang, Y. et al. Single molecule FRET reveals pore size and opening mechanism of a mechano-sensitive ion channel. eLife 3, e01834 (2014).

    PubMed  PubMed Central  Google Scholar 

  33. Pliotas, C . et al. The role of lipids in mechanosensation. Nat. Struct. Mol. Biol. 22, 991–8 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Walker, B., Krishnasastry, M., Zorn, L. & Bayley, H. Assembly of the oligomeric membrane pore formed by staphylococcal alpha-hemolysin examined by truncation mutagenesis. J. Biol. Chem. 267, 21782–6 (1992).

    CAS  PubMed  Google Scholar 

  35. Walker, B., Braha, O., Cheley, S. & Bayley, H. An intermediate in the assembly of a pore-forming protein trapped with a genetically-engineered switch. Chem. Biol. 2, 99–105 (1995).

    CAS  PubMed  Google Scholar 

  36. Dunstone, M. A. & Tweten, R. K. Packing a punch: the mechanism of pore formation by cholesterol dependent cytolysins and membrane attack complex/perforin-like proteins. Curr. Opin. Struct. Biol. 22, 342–349 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Leung, C. et al. Stepwise visualization of membrane pore formation by suilysin, a bacterial cholesterol-dependent cytolysin. eLife 3, e04247 (2014).

    PubMed  PubMed Central  Google Scholar 

  38. Stoddart, D. et al. Functional truncated membrane pores. Proc. Natl Acad. Sci. USA 111, 2425–2430 (2014).

    CAS  PubMed  Google Scholar 

  39. Karginov, V. A. Cyclodextrin derivatives as anti-infectives. Curr. Opin. Pharmacol. 13, 717–725 (2013).

    CAS  PubMed  Google Scholar 

  40. Brogden, K. A. Antimicrobial peptides: pore formers or metabolic inhibitors in bacteria? Nat. Rev. Microbiol. 3, 238–250 (2005).

    CAS  PubMed  Google Scholar 

  41. Cirac, A. D. et al. The molecular basis for antimicrobial activity of pore-forming cyclic peptides. Biophys. J. 100, 2422–2431 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  42. Song, C. et al. Crystal structure and functional mechanism of a human antimicrobial membrane channel. Proc. Natl Acad. Sci. USA 110, 4586–4591 (2013).

    CAS  PubMed  Google Scholar 

  43. Haswell, E. S., Phillips, R. & Rees, D. C. Mechanosensitive channels: what can they do and how do they do it? Structure 19, 1356–1369 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  44. Naismith, J. H. & Booth, I. R. Bacterial mechanosensitive channels—MscS: evolution's solution to creating sensitivity in function. Annu. Rev. Biophys. 41, 157–177 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Lee, J. & Bayley, H. Semisynthetic protein nanoreactor for single-molecule chemistry. Proc. Natl Acad. Sci. USA 112, 13768–13773 (2015).

    CAS  PubMed  Google Scholar 

  46. Fernandez-Lopez, S. et al. Antibacterial agents based on the cyclic D,L-alpha-peptide architecture. Nature 412, 452–455 (2001).

    CAS  PubMed  Google Scholar 

  47. Fjell, C. D., Hiss, J. A., Hancock, R. E. & Schneider, G. Designing antimicrobial peptides: form follows function. Nat. Rev. Drug. Discov. 11, 37–51 (2012).

    CAS  Google Scholar 

  48. Hoskin, D. W. & Ramamoorthy, A. Studies on anticancer activities of antimicrobial peptides. Biochim. Biophys. Acta 1778, 357–375 (2008).

    CAS  PubMed  Google Scholar 

  49. Gaspar, D., Veiga, A. S. & Castanho, M. A. From antimicrobial to anticancer peptides. A review. Front. Microbiol. 4, 294 (2013).

    PubMed  PubMed Central  Google Scholar 

  50. Mantri, S., Tanuj Sapra, K., Cheley, S., Sharp, T. H. & Bayley, H. An engineered dimeric protein pore that spans adjacent lipid bilayers. Nat. Commun. 4, 1725 (2013).

    PubMed  PubMed Central  Google Scholar 

  51. Gutsmann, T., Heimburg, T., Keyser, U., Mahendran, K. R. & Winterhalter, M. Protein reconstitution into freestanding planar lipid membranes for electrophysiological characterization. Nat. Protoc. 10, 188–198 (2015).

    PubMed  Google Scholar 

Download references

Acknowledgements

The authors acknowledge a Biotechnology and Biological Sciences Research Council grant (BB/J009784/1) and the European Research Council (340764) for financial support. D.N.W. holds a Royal Society Wolfson Research Merit Award.

Author information

Authors and Affiliations

Authors

Contributions

K.R.M. performed and analysed the current recordings. A.N. synthesized peptides and determined their biophysical properties. L.K. produced the Wza protein and synthesized the CD derivatives. A.N. and A.R.T. performed the molecular modelling. A.N. and R.B.S. performed the molecular dynamics simulations. K.R.M., A.N., D.N.W. and H.B. designed experiments and wrote the paper.

Corresponding authors

Correspondence to Derek N. Woolfson or Hagan Bayley.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 3826 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mahendran, K., Niitsu, A., Kong, L. et al. A monodisperse transmembrane α-helical peptide barrel. Nature Chem 9, 411–419 (2017). https://doi.org/10.1038/nchem.2647

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.2647

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing