Voltage-induced bending and electromechanical coupling in lipid bilayers.
The electrical properties of the cellular membrane are important for ion transport across cells and electrophysiology. Plasma membranes also resist bending and stretching, and mechanical properties of the membrane influence cell shape and forces in membrane tethers pulled from cells. There exists a coupling between the electrical and mechanical properties of the membrane. Previous work has shown that applied voltages can induce forces and movements in the lipid bilayer. We present a theory that computes membrane bending deformations and forces as the applied voltage is changed. We discover that electromechanical coupling in lipid bilayers depends on the voltage-dependent adsorption of ions into the region occupied by the phospholipid head groups. A simple model of counter-ion absorption is investigated. We show that electromechanical coupling can be measured using membrane tethers and we use our model to predict the membrane tether tension as a function of applied voltage. We also discuss how electromechanical coupling in membranes may influence transmembrane protein function.
Harland
Ben
B
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Brownell
William E
WE
Spector
Alexander A
AA
Sun
Sean X
SX
D003198:Computer Simulation; D055119:Elastic Modulus; D004574:Electromagnetic Fields; D008051:Lipid Bilayers / Q000737:chemistry* / Q000528:radiation effects*; D008560:Membrane Fluidity / Q000528:radiation effects*; D008956:Models, Chemical; D008958:Models, Molecular; D013314:Stress, Mechanical
D008051:Lipid Bilayers