Modulation of gramicidin A open channel lifetime by ion occupancy

摘要: The hypothesis that the gramicidin A channel stability depends on level of ion occupancy was used to derive a mathematical model relating lifetime occupancy. Eyring barrier permeation models were examined for their ability fit zero-voltage conductance, current-voltage, as well data. simplest required explain major features experimental data consists three barriers and four sites (3B4S) with maximum two ions occupying channel. average calculated from by assuming closing rate constant be proportional probability internal being empty. link between has its single parameter experimentally determined averaged channels in limit infinitely dilute solutions therefore no adjustable parameters. This simple assumption one or more inside completely stabilize dimer conformation is successful explaining considering fact this stabilization independent species configurational examine, comparison data, asymmetrical voltage dependence solutions, effects blockers, elevated osmotic pressure.