Equilibrium distribution of K+ ions in the hydrophilic spacer of tethered bilayer lipid membranes

摘要: Tethered bilayer lipid membranes (tBLMs) have been extensively employed to investigate the function of channel-forming peptides and proteins. They consist a tethered surface an Au or Hg electrode through oligopeptide polyethyleneoxy “hydrophilic spacer”. Upon incorporating ion-selective channel in tBLM, equilibrium distribution permeating ion along hydrophilic spacer is attained at each applied potential. An electrochemical model tBLMs developed calculate concentration profile as The limited spaciousness accounted for by imposing maximum local volume ion. present approach general. In this work, it particular mercury-supported (tetraethyleneoxy spacer)|(phospholipid bilayer) tBLM bathed aqueous solution 0.1 M KCl. Penetration K+ ions into was realized either carrier valinomycin gramicidin. charge cation potential determined jumping given from fixed positive enough exclude presence spacer.