Skip to main content

Thank you for visiting 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.

Modest stabilization by most hydrogen-bonded side-chain interactions in membrane proteins


Understanding the energetics of molecular interactions is fundamental to all of the central quests of structural biology including structure prediction and design, mapping evolutionary pathways, learning how mutations cause disease, drug design, and relating structure to function. Hydrogen-bonding is widely regarded as an important force in a membrane environment because of the low dielectric constant of membranes and a lack of competition from water1,2,3,4,5,6. Indeed, polar residue substitutions are the most common disease-causing mutations in membrane proteins6,7. Because of limited structural information and technical challenges, however, there have been few quantitative tests of hydrogen-bond strength in the context of large membrane proteins. Here we show, by using a double-mutant cycle analysis, that the average contribution of eight interhelical side-chain hydrogen-bonding interactions throughout bacteriorhodopsin is only 0.6 kcal mol-1. In agreement with these experiments, we find that 4% of polar atoms in the non-polar core regions of membrane proteins have no hydrogen-bond partner and the lengths of buried hydrogen bonds in soluble proteins and membrane protein transmembrane regions are statistically identical. Our results indicate that most hydrogen-bond interactions in membrane proteins are only modestly stabilizing. Weak hydrogen-bonding should be reflected in considerations of membrane protein folding, dynamics, design, evolution and function.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Double-mutant cycles for hydrogen-bonding interactions in bacteriorhodopsin.
Figure 2: Characterization of the T90A, D115A and T90A/D115A mutants.
Figure 3: Comparison of average hydrogen-bond distances in different environments.

Accession codes

Primary accessions

Protein Data Bank

Data deposits

Coordinates and structure factors for the D115A and T90A/D115A mutant bacteriorhodopsins have been deposited in the Protein Data Bank under accession codes 3COC and 3COD, respectively.


  1. 1

    White, S. H. How hydrogen bonds shape membrane protein structure. Adv. Protein Chem. 72, 157–172 (2005)

    Article  PubMed  Google Scholar 

  2. 2

    Popot, J. L. & Engelman, D. M. Helical membrane protein folding, stability, and evolution. Annu. Rev. Biochem. 69, 881–922 (2000)

    CAS  Article  PubMed  Google Scholar 

  3. 3

    Zhou, F. X., Merianos, H. J., Brunger, A. T. & Engelman, D. M. Polar residues drive association of polyleucine transmembrane helices. Proc. Natl Acad. Sci. USA 98, 2250–2255 (2001)

    ADS  CAS  Article  PubMed  Google Scholar 

  4. 4

    Gratkowski, H., Lear, J. D. & DeGrado, W. F. Polar side chains drive the association of model transmembrane peptides. Proc. Natl Acad. Sci. USA 98, 880–885 (2001)

    ADS  CAS  Article  PubMed  Google Scholar 

  5. 5

    Adamian, L. & Liang, J. Interhelical hydrogen bonds and spatial motifs in membrane proteins: polar clamps and serine zippers. Proteins 47, 209–218 (2002)

    CAS  Article  PubMed  Google Scholar 

  6. 6

    Partridge, A. W., Therien, A. G. & Deber, C. M. Polar mutations in membrane proteins as a biophysical basis for disease. Biopolymers 66, 350–358 (2002)

    CAS  Article  PubMed  Google Scholar 

  7. 7

    Partridge, A. W., Therien, A. G. & Deber, C. M. Missense mutations in transmembrane domains of proteins: phenotypic propensity of polar residues for human disease. Proteins 54, 648–656 (2004)

    CAS  Article  PubMed  Google Scholar 

  8. 8

    Call, M. E. et al. The structure of the ζζ transmembrane dimer reveals features essential for its assembly with the T cell receptor. Cell 127, 355–368 (2006)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  9. 9

    Faham, S. et al. Side-chain contributions to membrane protein structure and stability. J. Mol. Biol. 335, 297–305 (2004)

    CAS  Article  PubMed  Google Scholar 

  10. 10

    Duong, M. T., Jaszewski, T. M., Fleming, K. G. & MacKenzie, K. R. Changes in apparent free energy of helix–helix dimerization in a biological membrane due to point mutations. J. Mol. Biol. 371, 422–434 (2007)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  11. 11

    Myers, J. K. & Pace, C. N. Hydrogen bonding stabilizes globular proteins. Biophys. J. 71, 2033–2039 (1996)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  12. 12

    Busenlehner, L. S. & Armstrong, R. N. Insights into enzyme structure and dynamics elucidated by amide H/D exchange mass spectrometry. Arch. Biochem. Biophys. 433, 34–46 (2005)

    CAS  Article  PubMed  Google Scholar 

  13. 13

    Busenlehner, L. S. et al. Stress sensor triggers conformational response of the integral membrane protein microsomal glutathione transferase 1. Biochemistry 43, 11145–11152 (2004)

    CAS  Article  PubMed  Google Scholar 

  14. 14

    Molday, R. S., Englander, S. W. & Kallen, R. G. Primary structure effects on peptide group hydrogen exchange. Biochemistry 11, 150–158 (1972)

    CAS  Article  PubMed  Google Scholar 

  15. 15

    O’Neil, J. D. & Sykes, B. D. NMR studies of the influence of dodecyl sulfate on the amide hydrogen exchange kinetics of a micelle-solubilized hydrophobic tripeptide. Biochemistry 28, 699–707 (1989)

    Article  PubMed  Google Scholar 

  16. 16

    Hong, H., Szabo, G. & Tamm, L. K. Electrostatic couplings in OmpA ion-channel gating suggest a mechanism for pore opening. Nature Chem. Biol. 2, 627–635 (2006)

    CAS  Article  Google Scholar 

  17. 17

    Fersht, A. R., Matouschek, A. & Serrano, L. The folding of an enzyme. I. Theory of protein engineering analysis of stability and pathway of protein folding. J. Mol. Biol. 224, 771–782 (1992)

    CAS  Article  PubMed  Google Scholar 

  18. 18

    Fleming, P. J. & Rose, G. D. Do all backbone polar groups in proteins form hydrogen bonds? Protein Sci. 14, 1911–1917 (2005)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  19. 19

    Adamian, L., Nanda, V., DeGrado, W. F. & Liang, J. Empirical lipid propensities of amino acid residues in multispan alpha helical membrane proteins. Proteins 59, 496–509 (2005)

    CAS  Article  PubMed  Google Scholar 

  20. 20

    Rees, D., DeAntonio, L. & Eisenberg, D. Hydrophobic organization of membrane proteins. Science 245, 510–513 (1989)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Stanley, A. M. & Fleming, K. G. The role of a hydrogen bonding network in the transmembrane β-barrel OMPLA. J. Mol. Biol. 370, 912–924 (2007)

    CAS  Article  PubMed  Google Scholar 

  22. 22

    Fleming, K. G. & Engelman, D. M. Specificity in transmembrane helix–helix interactions can define a hierarchy of stability for sequence variants. Proc. Natl Acad. Sci. USA 98, 14340–14344 (2001)

    ADS  CAS  Article  PubMed  Google Scholar 

  23. 23

    Senes, A., Engel, D. E. & DeGrado, W. F. Folding of helical membrane proteins: the role of polar, GxxxG-like and proline motifs. Curr. Opin. Struct. Biol. 14, 465–479 (2004)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  24. 24

    Lear, J. D., Gratkowski, H., Adamian, L., Liang, J. & DeGrado, W. F. Position-dependence of stabilizing polar interactions of asparagine in transmembrane helical bundles. Biochemistry 42, 6400–6407 (2003)

    CAS  Article  Google Scholar 

  25. 25

    Rosenbaum, D. M. et al. GPCR engineering yields high-resolution structural insights into β2-adrenergic receptor function. Science 318, 1266–1273 (2007)

    ADS  CAS  Article  Google Scholar 

  26. 26

    Shan, S. O. & Herschlag, D. Hydrogen bonding in enzymatic catalysis: analysis of energetic contributions. Methods Enzymol. 308, 246–276 (1999)

    CAS  Article  PubMed  Google Scholar 

  27. 27

    Faham, S. & Bowie, J. U. Bicelle crystallization: a new method for crystallizing membrane proteins yields a monomeric bacteriorhodopsin structure. J. Mol. Biol. 316, 1–6 (2002)

    CAS  Article  PubMed  Google Scholar 

  28. 28

    Chamberlain, A. K., Lee, Y., Kim, S. & Bowie, J. U. Snorkeling preferences foster an amino acid composition bias in transmembrane helices. J. Mol. Biol. 339, 471–479 (2004)

    CAS  Article  PubMed  Google Scholar 

  29. 29

    McDonald, I. K. & Thornton, J. M. Satisfying hydrogen bonding potential in proteins. J. Mol. Biol. 238, 777–793 (1994)

    CAS  Article  PubMed  Google Scholar 

  30. 30

    Otwinowski, Z. & Minor, W. Processing of X-ray diffraction data collected in oscillation mode. Methods Enzymol. 276, 307–326 (1997)

    CAS  Article  Google Scholar 

  31. 31

    Brunger, A. T. et al. Crystallography & NMR system: A new software suite for macromolecular structure determination. Acta Crystallogr. D Biol. Crystallogr. 54, 905–921 (1998)

    CAS  Article  PubMed  Google Scholar 

  32. 32

    Hamuro, Y. et al. Dynamics of cAPK type IIβ activation revealed by enhanced amide H/2H exchange mass spectrometry (DXMS). J. Mol. Biol. 327, 1065–1076 (2003)

    CAS  Article  PubMed  Google Scholar 

  33. 33

    Zhang, Z. & Marshall, A. G. A universal algorithm for fast and automated charge state deconvolution of electrospray mass-to-charge ratio spectra. J. Am. Soc. Mass Spectrom. 9, 225–233 (1998)

    CAS  Article  PubMed  Google Scholar 

  34. 34

    Zhang, Z., Li, W., Logan, T. M., Li, M. & Marshall, A. G. Human recombinant [C22A] FK506-binding protein amide hydrogen exchange rates from mass spectrometry match and extend those from NMR. Protein Sci. 6, 2203–2217 (1997)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  35. 35

    Luecke, H., Schobert, B., Richter, H. T., Cartailler, J. P. & Lanyi, J. K. Structure of bacteriorhodopsin at 1.55 Å resolution. J. Mol. Biol. 291, 899–911 (1999)

    CAS  Article  PubMed  Google Scholar 

  36. 36

    Jormakka, M., Tornroth, S., Byrne, B. & Iwata, S. Molecular basis of proton motive force generation: structure of formate dehydrogenase-N. Science 295, 1863–1868 (2002)

    ADS  Article  PubMed  Google Scholar 

  37. 37

    Khademi, S. et al. Mechanism of ammonia transport by Amt/MEP/Rh: structure of AmtB at 1.35 Å. Science 305, 1587–1594 (2004)

    ADS  CAS  Article  PubMed  Google Scholar 

  38. 38

    Yamashita, A., Singh, S. K., Kawate, T., Jin, Y. & Gouaux, E. Crystal structure of a bacterial homologue of Na+/Cl-dependent neurotransmitter transporters. Nature 437, 215–223 (2005)

    ADS  CAS  Article  Google Scholar 

  39. 39

    Andrade, S. L., Dickmanns, A., Ficner, R. & Einsle, O. Crystal structure of the archaeal ammonium transporter Amt-1 from Archaeoglobus fulgidus . Proc. Natl Acad. Sci. USA 102, 14994–14999 (2005)

    ADS  CAS  Article  PubMed  Google Scholar 

  40. 40

    Lees, A. M., Deconinck, A. E., Campbell, B. D. & Lees, R. S. Atherin: a newly identified, lesion-specific, LDL-binding protein in human atherosclerosis. Atherosclerosis 182, 219–230 (2005)

    CAS  Article  PubMed  Google Scholar 

Download references


We thank the staff at the beamlines 8.2.1 and 8.2.2 at the Advanced Light Source; F. Pettit for advice on statistics; M. Philips for assisting with circular dichroism experiments; S. Bassilian for assisting with LC–MS analysis of intact bacteriorhodopsin; Y. Ihm for the identification of transmembrane regions; Z. Zhang for providing deuterium-exchange data reduction software MAGTRAN and LAPLACE; N. L. Kelleher for providing the acid-labile detergent; and M. Chamberlain, H. Cheng, E. Gendel, H. Hong, Y. Ihm, A. D. Meruelo, T. Mitchell and R. Stafford for critically reading the manuscript. This work was supported by National Institutes of Health grant RO1 GM063919 (J.U.B.) and by the National Institutes of Health National Cancer Institute Innovative Molecular Analysis Technologies Program (V.L.W.).

Author Contributions N.H.J. and J.U.B. designed the research and prepared the manuscript. N.H.J. performed the vast majority of the experiments and structure analyses. A.M. and D.Y. assisted with mutagenesis and protein purification. A.M. crystallized the T90A/D115A mutant. S.F. collected and processed some diffraction data and helped with structure determination and refinement. J.P.W. assisted site-directed mutagenesis verification by LC–MS analysis of intact bacteriorhodopsin, provided technical advice on mass spectrometry, and helped develop the H/D exchange method. V.L.W. assisted in H/D exchange data analysis, including the provision of specialized software and hardware, and provided help with H/D exchange methods.

Author information



Corresponding author

Correspondence to James U. Bowie.

Supplementary information

Supplementary Information

The file contains Supplementary Methods, Supplementary Tables 1-2, Supplementary Figures 1-3 with legends, and additional references. (PDF 478 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Joh, N., Min, A., Faham, S. et al. Modest stabilization by most hydrogen-bonded side-chain interactions in membrane proteins. Nature 453, 1266–1270 (2008).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


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