We present a theoretical study on structural and electronic aspects of K+ permeation through the binding sites of the KcsA channel's selectivity filter. Density functional calculations are carried out on models taken from selected snapshots of a molecular dynamics simulation recently reported [FEBS Lett. 477 (2000) 37]. During the translocation process from one binding site to the other, the coordination number of the permeating K+ ion turns out to decrease and K+ ion polarizes significantly its ligands, backbone carbonyl groups and a water molecule. K+-induced polarization increases significantly at the transition state ITS) between the two binding sites. These findings suggest that polarization effects play a significant role in the microscopic mechanisms regulating potassium permeation. (C) 2002 Elsevier Science B.V All rights reserved.
Titolo: | Potassium permeation through the KcsA channel: a density functional study |
Autori: | |
Data di pubblicazione: | 2002 |
Rivista: | |
Abstract: | We present a theoretical study on structural and electronic aspects of K+ permeation through the binding sites of the KcsA channel's selectivity filter. Density functional calculations are carried out on models taken from selected snapshots of a molecular dynamics simulation recently reported [FEBS Lett. 477 (2000) 37]. During the translocation process from one binding site to the other, the coordination number of the permeating K+ ion turns out to decrease and K+ ion polarizes significantly its ligands, backbone carbonyl groups and a water molecule. K+-induced polarization increases significantly at the transition state ITS) between the two binding sites. These findings suggest that polarization effects play a significant role in the microscopic mechanisms regulating potassium permeation. (C) 2002 Elsevier Science B.V All rights reserved. |
Handle: | http://hdl.handle.net/11697/1650 |
Appare nelle tipologie: | 1.1 Articolo in rivista |