title: Functions of the hydrophilic channels in protonmotive cytochrome c oxidase.
abstract: The structures and functions of hydrophilic channels in electron-transferring membrane proteins are discussed. A distinction is made between proton channels that can conduct protons and dielectric channels that are non-conducting but can dielectrically polarize in response to the introduction of charge changes in buried functional centres. Functions of the K, D and H channels found in A1-type cytochrome c oxidases are reviewed in relation to these ideas. Possible control of function by dielectric channels and their evolutionary relation to proton channels is explored.
authors.affiliation: Glynn Laboratory of Bioenergetics, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK. prr@ucl.ac.uk
authors.forename: Peter R
authors.initials: PR
authors.lastname: Rich
authors.forename: Amandine
authors.initials: A
authors.lastname: Maréchal
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D006801:Humans; D018892:Proton-Motive Force / Q000502:physiology*
chemical_list: D003576:Electron Transport Complex IV
keywords: charge transfer; dielectric properties; electrostatics; hydrophilic channels; proton transfer; redox proteins