ArticleBiophysical journal1999
Permeation of ions across the potassium channel: Brownian dynamics studies.
Article in Biophysical journal, 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 65 papers.
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Who cites it
65 citing papers in PubMed, 201 citations in OpenAlex.
- Article
- Non-trivial dynamics in a model of glial membrane voltage driven by open potassium pores.Biophysical journal · 2023Article
- Article
- Biochemical and physiological properties of KChemico-biological interactions · 2019Review
- Channel function reconstitution and re-animation: a single-channel strategy in the postcrystal age.The Journal of physiology · 2015Review
- Simulating Current-Voltage Relationships for a Narrow Ion Channel Using the Weighted Ensemble Method.Journal of chemical theory and computation · 2015Article
- Multi-ion versus single-ion conduction mechanisms can yield current rectification in biological ion channels.Journal of biological physics · 2014Article
- Interacting ions in biophysics: real is not ideal.Biophysical journal · 2013Review
- Electrodiffusive model for astrocytic and neuronal ion concentration dynamics.PLoS computational biology · 2013Article
- Molecular dynamics simulations of membrane proteins.Biophysical reviews · 2012Review
- Particle-based simulation of charge transport in discrete-charge nano-scale systems: the electrostatic problem.Nanoscale research letters · 2012Article
- On the selective ion binding hypothesis for potassium channels.Proceedings of the National Academy of Sciences of the United States of America · 2011Article
- A method for treating the passage of a charged hard sphere ion as it passes through a sharp dielectric boundary.The Journal of chemical physics · 2011Article
- Origins of ion selectivity in potassium channels from the perspective of channel block.The Journal of general physiology · 2011Review
- Comparative study of the energetics of ion permeation in Kv1.2 and KcsA potassium channels.Biophysical journal · 2011Article
- Testing the applicability of Nernst-Planck theory in ion channels: comparisons with Brownian dynamics simulations.PloS one · 2011Article
- Molecular dynamics and brownian dynamics investigation of ion permeation and anesthetic halothane effects on a proton-gated ion channel.Journal of the American Chemical Society · 2010Article
- Ion conduction in ligand-gated ion channels: Brownian dynamics studies of four recent crystal structures.Biophysical journal · 2010Article
- Reinterpreting the anomalous mole fraction effect: the ryanodine receptor case study.Biophysical journal · 2009Article
- Computational study of the transmembrane domain of the acetylcholine receptor.European biophysics journal : EBJ · 2009Article
5 more citing papers are in PubMed but not listed here.
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The physical mechanisms underlying the transport of ions across a model potassium channel are described. The shape of the model channel corresponds closely to that deduced from crystallography. From electrostatic calculations, we show that an ion permeating the channel, in the absence of any residual charges, encounters an insurmountable energy barrier arising from induced surface charges. Carbonyl groups along the selectivity filter, helix dipoles near the oval chamber, and mouth dipoles near the channel entrances together transform the energy barrier into a deep energy well. Two ions are attracted to this well, and their presence in the channel permits ions to diffuse across it under the influence of an electric field. Using Brownian dynamics simulations, we determine the magnitude of currents flowing across the channel under various conditions. The conductance increases with increasing dipole strength and reaches its maximum rapidly; a further increase in dipole strength causes a steady decrease in the channel conductance. The current also decreases systematically when the effective dielectric constant of the channel is lowered. The conductance with the optimal choice of dipoles reproduces the experimental value when the dielectric constant of the channel is assumed to be 60. The current-voltage relationship obtained with symmetrical solutions is linear when the applied potential is less than approximately 100 mV but deviates from Ohm's law at a higher applied potential. The reversal potentials obtained with asymmetrical solutions are in agreement with those predicted by the Nernst equation. The conductance exhibits the saturation property observed experimentally. We discuss the implications of these findings for the transport of ions across the potassium channels and membrane channels in general.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.