Voltage-gated lipid ion channels

Abstract

Synthetic lipid membranes can display channel-like ion conduction events even in the absence of proteins. We show here that these events are voltage-gated with a quadratic voltage dependence as expected from electrostatic theory of capacitors. To this end, we recorded channel traces and current histograms in patch-experiments on lipid membranes. We derived a theoretical current-voltage relationship for pores in lipid membranes that describes the experimental data very well when assuming an asymmetric membrane. We determined the equilibrium constant between closed and open state and the open probability as a function of voltage. The voltage-dependence of the lipid pores is found comparable to that of protein channels. Lifetime distributions of open and closed events indicate that the channel open distribution does not follow exponential statistics but rather power law behavior for long open times.

10 pages, 7 figures - Strongly revised version compared to first version. Accepted by PLOS one, April 2013

References in corpus (9)

• The temperature dependence of lipid membrane permeability, its quantized nature, and the influence of anesthetics
• The thermodynamics of general anesthesia
• Lipid Ion Channels
• The capacitance and electromechanical coupling of lipid membranes close to transitions. The effect of electrostriction
• Phase state dependent current fluctuations in pure lipid membranes
• The influence of anesthetics, neurotransmitters and antibiotics on the relaxation processes in lipid membranes
• Comparing ion conductance recordings of synthetic lipid bilayers with cell membranes containing TRP channels
• Ion-channel-like behavior in lipid bilayer membranes at the melting transition
• The thermodynamics of lipid ion channel formation in the absence and presence of anesthetics. BLM experiments and simulations

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• The excitable fluid mosaic
• Nonlinear conductance, rectification and mechanosensitive channel formation of lipid membranes
• Design and Stability Analysis of an Electromechanical Model for Nerves