title: Bead-like passage of chloride ions through ClC chloride channels.
abstract: The ClC chloride channels control the ionic composition of the cytoplasm and the volume of cells, and regulate electrical excitability. Recently, it has been proposed that prokaryotic ClC channels are H+-Cl- exchange transporter. Although X-ray and molecular dynamics (MD) studies of bacterial ClC channels have investigated the filter open-close and ion permeation mechanism of channels, details have remained unclear. We performed MD simulations of ClC channels involving H+, Na+, K+, or H3O+ in the intracellular region to elucidate the open-close mechanism, and to clarify the role of H+ ion an H+-Cl- exchange transporter. Our simulations revealed that H+ and Na+ caused channel opening and the passage of Cl- ions. Na+ induced a bead-like string of Cl- -Na+-Cl--Na+-Cl- ions to form and permeate through ClC channels to the intracellular side with the widening of the channel pathway.
authors.affiliation: Bioinformatics Group, RIKEN Genomic Sciences Center, 61-1 Ono, Tsurumi, Yokohama, Kanagawa 230-0046, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suenaga
authors.forename: Jay Z
authors.initials: JZ
authors.lastname: Yeh
authors.forename: Makoto
authors.initials: M
authors.lastname: Taiji
authors.forename: Akira
authors.initials: A
authors.lastname: Toyama
authors.forename: Hideo
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Mingyu
authors.initials: M
authors.lastname: Son
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Takayama
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Iwamoto
authors.forename: Ikuro
authors.initials: I
authors.lastname: Sato
authors.forename: Toshio
authors.initials: T
authors.lastname: Narahashi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Konagaya
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Goto
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000502:physiology; D002463:Cell Membrane Permeability; D018118:Chloride Channels / Q000737:chemistry* / Q000502:physiology*; D002712:Chlorides / Q000378:metabolism*; D003198:Computer Simulation; D017136:Ion Transport; D008954:Models, Biological; D008958:Models, Molecular; D012964:Sodium / Q000493:pharmacokinetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D018118:Chloride Channels; D002712:Chlorides; D012964:Sodium