Membranes (Apr 2022)

Experimental Investigations on the Conductance of Lipid Membranes under Differential Hydrostatic Pressure

  • Rose Whiting,
  • Pangaea W. Finn,
  • Andrew Bogard,
  • Fulton McKinney,
  • Dallin Pankratz,
  • Aviana R. Smith,
  • Elen A. Gardner,
  • Daniel Fologea

DOI
https://doi.org/10.3390/membranes12050479
Journal volume & issue
Vol. 12, no. 5
p. 479

Abstract

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The unassisted transport of inorganic ions through lipid membranes has become increasingly relevant to an expansive range of biological phenomena. Recent simulations indicate a strong influence of a lipid membrane’s curvature on its permeability, which may be part of the overall cell sensitivity to mechanical stimulation. However, most ionic permeability experiments employ a flat, uncurved lipid membrane, which disregards the physiological relevance of curvature on such investigations. To fill this gap in our knowledge, we adapted a traditional experimental system consisting of a planar lipid membrane, which we exposed to a controlled, differential hydrostatic pressure. Our electrophysiology experiments indicate a strong correlation between the changes in membrane geometry elicited by the application of pressure, as inferred from capacitance measurements, and the resulting conductance. Our experiments also confirmed the well-established influence of cholesterol addition to lipid membranes in adjusting their mechanical properties and overall permeability. Therefore, the proposed experimental system may prove useful for a better understanding of the intricate connections between membrane mechanics and adjustments of cellular functionalities upon mechanical stimulation, as well as for confirmation of predictions made by simulations and theoretical modeling.

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