Ion conduction in the KcsA potassium channel analyzed with a minimal kinetic model.
We use a model by Nelson to study the current-voltage and conductance-concentration curves of bacterial potassium channel KcsA without assuming rapid ion translocation. Ion association to the channel filter is rate controlling at low concentrations, but dissociation and transport in the filter can limit conduction at high concentration for ions other than K+. The absolute values of the effective rate constants are tentative but the relative changes in these constants needed to qualitatively explain the experiments should be of significance.
Mafé
Salvador
S
Department de Termodinàmica, Universitat de València, E-46100 Burjassot, Spain. smafe@uv.es
Pellicer
Julio
J
D001426:Bacterial Proteins / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology*; D003198:Computer Simulation; D004553:Electric Conductivity; D015640:Ion Channel Gating / Q000502:physiology*; D017136:Ion Transport / Q000502:physiology; D007700:Kinetics; D008564:Membrane Potentials / Q000502:physiology*; D008954:Models, Biological; D008956:Models, Chemical; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000502:physiology*
D001426:Bacterial Proteins; D015221:Potassium Channels; C107790:prokaryotic potassium channel; D011188:Potassium