title: Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel.
abstract: We demonstrate the electrical rectification and signal averaging of fluctuating signals using a biological nanostructure in aqueous solution: a single protein ion channel inserted in the lipid bilayer characteristic of cell membranes. The conversion of oscillating, zero time-average potentials into directional currents permits charging of a load capacitor to significant steady-state voltages within a few minutes in the case of the outer membrane porin F (OmpF) protein, a bacterial channel of Escherichia coli. The experiments and simulations show signal averaging effects at a more fundamental level than the traditional cell and tissue scales, which are characterized by ensembles of many ion channels operating simultaneously. The results also suggest signal transduction schemes with bio-electronic interfaces and ionic circuits where soft matter nanodiodes can be coupled to conventional electronic elements.
authors.affiliation: Dept. de Física, Universitat Jaume I de Castelló, E-12080 Castelló, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Verdia-Baguena
authors.affiliation: Departament de Física Aplicada, Universitat Politècnica de València, E-46022 València, Spain. patraho@fis.upv.es.
authors.forename: V
authors.initials: V
authors.lastname: Gomez
authors.affiliation: Dept. de Física de la Terra i Termodinàmica, Universitat de València, E-46100 Burjassot, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Cervera
authors.affiliation: Departament de Física Aplicada, Universitat Politècnica de València, E-46022 València, Spain. patraho@fis.upv.es.
authors.forename: P
authors.initials: P
authors.lastname: Ramirez
authors.affiliation: Dept. de Física de la Terra i Termodinàmica, Universitat de València, E-46100 Burjassot, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Mafe
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism*; D004553:Electric Conductivity; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D007473:Ion Channels / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D018272:Porins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; C109237:OmpF protein; D018272:Porins