European Biophysics Journal

, Volume 41, Issue 9, pp 769–776 | Cite as

Effect of salt on the interaction of Hal18 with lipid membranes

  • Sarah R. Dennison
  • Adam J. Phoenix
  • David A. PhoenixEmail author
Biophysics Letter


One of the major obstacles in the development of new antimicrobial peptides as novel antibiotics is salt sensitivity. Hal18, an α-helical subunit of Halocidin isolated from Halocynthia aurantium, has been previously shown to maintain its antimicrobial activity in high salt conditions. The α-helicity of Hal18 in the presence and absence of salt was demonstrated by circular dichroism spectroscopy, which showed that the peptide was mainly unordered containing β-strands and β-turns. However, in the presence of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylserine (DMPS) vesicles, Hal18 folded to form α-helices (circa 42 %). Furthermore, the structure was not significantly affected by pH or the presence of metal ions. These data were supported by monolayer results showing Hal18 induced stable surface pressure changes in monolayers composed of DMPC (5 mN m−1) and DMPS (8.5 mN m−1), which again were not effected by the presence of metal ions or pH. It is proposed that the hydrophobic groove within its molecular architecture enables the peptide to form stable associations with lipid membranes. The balance of hydrophobicity along the Hal18 long axis would also support oblique orientation of the peptide at the membrane interface. Hence, this model of membrane interaction would enable the peptide to penetrate deep into the membrane. This concept is supported by lysis data. Overall, it would appear that this peptide is a potential candidate for future AMP design for use in high salt environments.


Antimicrobial peptide α-Helical Hydrophobic groove Salt resistance Membrane interactive 


  1. Amaral L, Engi H, Viveiros M, Molnar J (2007) Review. Comparison of multidrug resistant efflux pumps of cancer and bacterial cells with respect to the same inhibitory agents. In Vivo (Athens, Greece) 21:237–244Google Scholar
  2. Bechinger B, Lohner K (2006) Detergent-like actions of linear amphipathic cationic antimicrobial peptides. Biochim Biophys Acta 1758:1529–1539PubMedCrossRefGoogle Scholar
  3. Demel RA (1974) Monolayers-description of use and interaction. Methods Enzymol 32:539–544PubMedCrossRefGoogle Scholar
  4. Dennison SR, Phoenix DA (2011) Influence of C-terminal amidation on the efficacy of modelin-5. Biochemistry 50:1514–1523PubMedCrossRefGoogle Scholar
  5. Dennison SR, Harris F, Phoenix DA (2005) Are oblique orientated alpha-helices used by antimicrobial peptides for membrane invasion? Protein Pept Lett 12:27–29PubMedCrossRefGoogle Scholar
  6. Dennison SR, Kim YS, Cha HJ, Phoenix DA (2008) Investigations into the ability of the peptide, HAL18, to interact with bacterial membranes. Eur Biophys J 38:37–43PubMedCrossRefGoogle Scholar
  7. Dennison SR, Harris F, Phoenix DA (2009) A study on the importance of phenylalanine for aurein functionality. Protein Pept Lett 16:1455–1458PubMedCrossRefGoogle Scholar
  8. Dooring G, Gulbins E (2009) Cystic fibrosis and innate immunity: how chloride channel mutations provoke lung disease. Cell Microbiol 11:208–216CrossRefGoogle Scholar
  9. Eisenberg D, Weiss RM, Terwillinger TC, Wilcox W (1982) Hydrophobic moment and protein structure. Faraday Symp Chem Soc 17:109–120CrossRefGoogle Scholar
  10. Eisenberg D, Schwarz E, Komaromy M, Wall R (1984) Analysis of membrane and surface protein sequences with the hydrophobic moment plot. J Mol Biol 179:125–142PubMedCrossRefGoogle Scholar
  11. Goldman MJ, Anderson GM, Stolzenberg ED, Kari UP, Zasloff M, Wilson JM (1997) Human beta-defensin-1 is a salt-sensitive antibiotic in lung that is inactivated in cystic fibrosis. Cell 88:553–560PubMedCrossRefGoogle Scholar
  12. Gootz TD (2006) The forgotten Gram-negative bacilli: what genetic determinants are telling us about the spread of antibiotic resistance. Biochem Pharmacol 71:1073–1084PubMedCrossRefGoogle Scholar
  13. Greenfield NJ (2006) Using circular dichroism spectra to estimate protein secondary structure. Nat Protoc 6:2876–2890Google Scholar
  14. Hallock KJ, Lee DK, Omnaas J, Mosberg HI, Ramamoorthy I (2002) Membrane composition determines pardaxin's mechanism of lipid bilayer disruption. Biophys J 83:1004–1013PubMedCrossRefGoogle Scholar
  15. Harris F, Wallace J, Phoenix DA (2000) Use of hydrophobic moment plot methodology to aid the identification of oblique orientated alpha-helices. Mol Membr Biol 17:201–207PubMedCrossRefGoogle Scholar
  16. Harris F, Dennison SR, Phoenix DA (2009) Anionic antimicrobial peptides from eukaryotic organisms. Curr Protein Pept Sci 10:585–606PubMedCrossRefGoogle Scholar
  17. Jang WS, Kim KN, Lee YS, Nam MH, Lee IH (2002) Halocidin: a new antimicrobial peptide from hemocytes of the solitary tunicate, Halocynthia aurantium. FEBS Lett 521:81–86PubMedCrossRefGoogle Scholar
  18. Jang WS, Kim CH, Kim KN, Park SY, Lee JH, Son SM, Lee IH (2003) Biological activities of synthetic analogs of halocidin, an antimicrobial peptide from the tunicate Halocynthia aurantium. Antimicrob Agents Chemother 47:2481–2486PubMedCrossRefGoogle Scholar
  19. Lai R, Takeuchi H, Lomas LO, Jonczy J, Rigden DJ, Rees HH, Turner PC (2004) A new type of antimicrobial protein with multiple histidines from the hard tick, Amblyomma hebraeum. FASEB J 18:1447–1449PubMedGoogle Scholar
  20. Lee IH, Zhao C, Nguyen T, Menzel L, Waring AJ, Sherman MA, Lehrer RI (2001) Clavaspirin, an antibacterial and haemolytic peptide from Styela clava. J Pept Res 58:445–456PubMedCrossRefGoogle Scholar
  21. Lehrer RI, Andrew Tincu J, Taylor SW, Menzel LP, Waring AJ (2003) Natural peptide antibiotics from tunicates: structures, functions and potential uses. Integr Comp Biol 43:313–322PubMedCrossRefGoogle Scholar
  22. Nguyen LT, Haney EF, Vogel HJ (2011) The expanding scope of antimicrobial peptide structures and their modes of action. Trends Biotechnol 29:464–472PubMedCrossRefGoogle Scholar
  23. Obritsch MD, Fish DN, MacLaren R, Jung R (2005) Nosocomial infections due to multidrug-resistant Pseudomonas aeruginosa: epidemiology and treatment options. Pharmacotherapy 25:1353–1364PubMedCrossRefGoogle Scholar
  24. Park IY, Cho JH, Kim KS, Kim YB, Kim MS, Kim SC (2004) Helix stability confers salt resistance upon helical antimicrobial peptides. J Biol Chem 279:13896–13901PubMedCrossRefGoogle Scholar
  25. Sato H, Feix JB (2006) Peptide-membrane interactions and mechanisms of membrane destruction by amphipathic alpha-helical antimicrobial peptides. Biochim Biophys Acta 1758:1245–1256PubMedCrossRefGoogle Scholar
  26. Wang G, Li Y, Li X (2005) Correlation of three-dimensional structures with the antibacterial activity of a group of peptides designed based on a nontoxic bacterial membrane anchor. J Biol Chem 280:5803–5811PubMedCrossRefGoogle Scholar
  27. Whitmore L, Woollett B, Miles AJ, Janes RW, Wallace BA (2010) The protein circular dichroism data bank, a web-based site for access to circular dichroism spectroscopic data. Structure 18:1267–1269PubMedCrossRefGoogle Scholar
  28. Yu L, Guo L, Ding JL, Ho B, Feng SS, Popplewell J, Swann M, Wohland T (2009) Interaction of an artificial antimicrobial peptide with lipid membranes. Biochim Biophys Acta 1788:333–344PubMedCrossRefGoogle Scholar

Copyright information

© European Biophysical Societies' Association 2012

Authors and Affiliations

  • Sarah R. Dennison
    • 1
  • Adam J. Phoenix
    • 2
  • David A. Phoenix
    • 1
    Email author
  1. 1.School of Pharmacy and Biomedical SciencesUniversity of Central LancashirePrestonUK
  2. 2.Merchant Taylors Boys SchoolCrosby, LiverpoolUK

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