Dynamics of K+ ion conduction through Kv1.2.
The crystallographic structure of a potassium channel, Kv1.2, in an open state makes it feasible to simulate entire K(+) ion permeation events driven by a voltage bias and, thereby, elucidate the mechanism underlying ion conduction and selectivity of this type of channel. This Letter demonstrates that molecular dynamics simulations can provide movies of the overall conduction of K(+) ions through Kv1.2. As suggested earlier, the conduction is concerted in the selectivity filter, involving 2-3 ions residing mainly at sites identified previously by crystallography and modeling. The simulations reveal, however, the jumps of ions between these sites and identify the sequence of multi-ion configurations involved in permeation.
Khalili-Araghi
Fatemeh
F
Beckman Institute, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Tajkhorshid
Emad
E
Schulten
Klaus
K
D003198:Computer Simulation; D004558:Electric Stimulation; D015640:Ion Channel Gating; D017136:Ion Transport; D051663:Kv1.2 Potassium Channel / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008954:Models, Biological; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011188:Potassium / Q000737:chemistry*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry
D051663:Kv1.2 Potassium Channel; D008051:Lipid Bilayers; D010714:Phosphatidylethanolamines; D021122:Protein Subunits; C057561:1-palmitoyl-2-oleoylphosphatidylethanolamine; D011188:Potassium