Modified Donnan potentials for ion transport through biological ion channels.
In the classical study of ion transport through charged membranes, Donnan potentials are used to approximate the difference between the applied electrostatic potential and the potential at the liquid/membrane interface. For very thin membranes (e.g., biological lipid bilayers), this discontinuous approximation of the potential is not sufficient. Here we derive a modification to the classic Donnan potential for ion transport through a biological ion channel embedded in a lipid bilayer. We also show how to derive the classic Donnan potential without the usual assumptions and estimate the amount of space charge at the liquid/membrane interface.
Gillespie
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Department of Physiology and Biophysics, University of Miami School of Medicine, P.O. Box 016430, Miami, Florida 33101-6430, USA. dirkg@chroma.med.miami.edu
Eisenberg
R S
RS
D001703:Biophysics / Q000379:methods*; D018118:Chloride Channels / Q000737:chemistry; D007473:Ion Channels / Q000502:physiology*; D017136:Ion Transport; D007477:Ions; D008051:Lipid Bilayers / Q000737:chemistry*; D015233:Models, Statistical; D008962:Models, Theoretical; D015221:Potassium Channels / Q000737:chemistry; D015222:Sodium Channels / Q000737:chemistry; D055672:Static Electricity
D018118:Chloride Channels; D007473:Ion Channels; D007477:Ions; D008051:Lipid Bilayers; D015221:Potassium Channels; D015222:Sodium Channels