The Journal of Membrane Biology

, Volume 246, Issue 11, pp 793–801 | Cite as

Nanoscale, Electric Field-Driven Water Bridges in Vacuum Gaps and Lipid Bilayers

  • Ming-Chak Ho
  • Zachary A. Levine
  • P. Thomas Vernier


Formation of a water bridge across the lipid bilayer is the first stage of pore formation in molecular dynamic (MD) simulations of electroporation, suggesting that the intrusion of individual water molecules into the membrane interior is the initiation event in a sequence that leads to the formation of a conductive membrane pore. To delineate more clearly the role of water in membrane permeabilization, we conducted extensive MD simulations of water bridge formation, stabilization, and collapse in palmitoyloleoylphosphatidylcholine bilayers and in water–vacuum–water systems, in which two groups of water molecules are separated by a 2.8 nm vacuum gap, a simple analog of a phospholipid bilayer. Certain features, such as the exponential decrease in water bridge initiation time with increased external electric field, are similar in both systems. Other features, such as the relationship between water bridge lifetime and the diameter of the water bridge, are quite different between the two systems. Data such as these contribute to a better and more quantitative understanding of the relative roles of water and lipid in membrane electropore creation and annihilation, facilitating a mechanism-driven development of electroporation protocols. These methods can be extended to more complex, heterogeneous systems that include membrane proteins and intracellular and extracellular membrane attachments, leading to more accurate models of living cells in electric fields.


Electropermeabilization Electroporation Electropore Molecular dynamics Water bridge Lipid electropore annihilation 


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Ming-Chak Ho
    • 1
  • Zachary A. Levine
    • 1
  • P. Thomas Vernier
    • 2
  1. 1.Department of Physics and AstronomyUniversity of Southern CaliforniaLos AngelesUSA
  2. 2.Ming Hsieh Department of Electrical EngineeringViterbi School of Engineering, University of Southern CaliforniaLos AngelesUSA

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