European Biophysics Journal

, Volume 40, Issue 4, pp 503–514

Effect of acyl chain structure and bilayer phase state on binding and penetration of a supported lipid bilayer by HPA3

  • Daniel J. Hirst
  • Tzong-Hsien Lee
  • Marcus J. Swann
  • Sharon Unabia
  • Yoonkyung Park
  • Kyung-Soo Hahm
  • Marie Isabel Aguilar
Original Paper

DOI: 10.1007/s00249-010-0664-1

Cite this article as:
Hirst, D.J., Lee, TH., Swann, M.J. et al. Eur Biophys J (2011) 40: 503. doi:10.1007/s00249-010-0664-1

Abstract

The effect of acyl chain structure and bilayer phase state on binding and penetration by the peptide HPA3 was studied using dual polarisation interferometry. This peptide is an analogue of Hp(2-20) derived from the N-terminus of Helicobacter pylori ribosomal protein L1 (RpL1) which has been shown to have antimicrobial and cell-penetrating properties. The binding of HPA3 to zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or 1-palmitolyl-2-oleyl-sn-glycero-3-phosphocholine (POPC) and negatively charged membranes composed of DMPC and 1,2-dimyristoyl-sn-glycero-3-(phosphor-rac-(1-glycerol)) (DMPG) or POPC and 1-palmitolyl-2-oleyl-sn-glycero-3-(phosphor-rac-(1-glycerol)) (POPG) was determined using dual polarisation interferometry (DPI). Mass and birefringence were measured in real time, enabling the creation of birefringence–mass plots for detailed analysis of the changes in lipid bilayer order during the peptide-binding process. HPA3 bound to all four lipids and the binding progressed as a single phase for the saturated gel phase bilayers DMPC and DMPC–DMPG. However, the binding process involved two or more phases, with penetration of the unsaturated fluid phase POPC and POPC–POPG bilayers. Structural changes in the saturated bilayer were partially reversible whereas binding to the unsaturated bilayer resulted in irreversible changes in membrane structure. These results demonstrate that more disordered unsaturated bilayers are more susceptible to further disorganisation and have a lower capacity to recover from peptide-induced structural changes than saturated ordered bilayers. In addition, this study further establishes DPI as powerful tool for analysis of multiphase peptide-insertion processes associated with complex structural changes in the liquid-crystalline membrane.

Keywords

Antimicrobial peptide Hp(2-20) Dual polarisation interferometry Supported lipid bilayer Birefringence 

Supplementary material

249_2010_664_MOESM1_ESM.pdf (404 kb)
Supplementary material 1 (PDF 404 kb)

Copyright information

© European Biophysical Societies' Association 2011

Authors and Affiliations

  • Daniel J. Hirst
    • 1
  • Tzong-Hsien Lee
    • 1
  • Marcus J. Swann
    • 2
  • Sharon Unabia
    • 1
  • Yoonkyung Park
    • 3
  • Kyung-Soo Hahm
    • 3
  • Marie Isabel Aguilar
    • 1
  1. 1.Department of Biochemistry & Molecular BiologyMonash UniversityClaytonAustralia
  2. 2.Farfield Group, Farfield House, Southmere CourtCreweUK
  3. 3.Research Center for Proteineous Materials (RCPM)Chosun UniversityGwangjuKorea

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