Molecular Dynamics Study of Ion Conduction and Selectivity in a Prokaryotic Ion Channel

Ion conduction and selectivity in acid-sensing ion channel 1

The ability of acid-sensing ion channels (ASICs) to discriminate among cations was assessed based on changes in conductance and reversal potential with ion substitution. Human ASIC1a was expressed in Xenopus laevis oocytes, and acid-induced currents were measured using two-electrode voltage clamp. Replacement of extracellular Na(+) with Li(+), K(+), Rb(+), or Cs(+) altered inward conductance an...

Ion conduction and selectivity in the ryanodine receptor channel.

The ryanodine receptor channel is an intracellular membrane Ca2+-release channel. The investigation of ion translocation and discrimination in individual channels under voltage-clamp conditions has revealed that the channel can sustain very high rates of cation translocation, has high affinity for divalent cations and displays relatively poor discrimination between physiologically relevant cati...

Molecular and Brownian dynamics study of ion selectivity and conductivity in the potassium channel

We employ recently revealed structural information for the potassium channel in molecular and Brownian dynamics simulations to investigate the physical mechanisms involved in the transport of ions across this channel. We show that ion selectivity arises from the ability of the channel protein to completely solvate potassium ions but not the smaller sodium ions. From energy and free energy pertu...

Ion conduction and selectivity in K(+) channels.

Potassium (K(+)) channels are tetrameric membrane-spanning proteins that provide a selective pore for the conductance of K(+) across the cell membranes. These channels are most remarkable in their ability to discriminate K(+) from Na(+) by more than a thousandfold and conduct at a throughput rate near diffusion limit. The recent progress in the structural characterization of K(+) channel provid...

Ion Conduction and Selectivity in K+ Channels