title: Highly Selective Artificial K(+) Channels: An Example of Selectivity-Induced Transmembrane Potential.
abstract: Natural KcsA K(+) channels conduct at high rates with an extraordinary selectivity for K(+) cations, excluding the Na(+) or other cations. Biomimetic artificial channels have been designed in order to mimick the ionic activity of KcSA channels, but simple artificial systems presenting high K(+)/Na(+) selectivity are rare. Here we report an artificial ion channel of H-bonded hexyl-benzoureido-15-crown-5-ether, where K(+) cations are highly preferred to Na(+) cations. The K(+)-channel conductance is interpreted as arising in the formation of oligomeric highly cooperative channels, resulting in the cation-induced membrane polarization and enhanced transport rates without or under pH-active gradient. These channels are selectively responsive to the presence of K(+) cations, even in the presence of a large excess of Na(+). From the conceptual point of view, these channels express a synergistic adaptive behavior: the addition of the K(+) cation drives the selection and the construction of constitutional polarized ion channels toward the selective conduction of the K(+) cation that promotes their generation in the first place.
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UMII-CNRS UMR-5635 , Place Eugène Bataillon, CC 047, F-34095 Montpellier, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gilles
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UMII-CNRS UMR-5635 , Place Eugène Bataillon, CC 047, F-34095 Montpellier, France.|MOE Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, China.
authors.forename: Mihail
authors.initials: M
authors.lastname: Barboiu
mesh_terms: D006860:Hydrogen Bonding; D008564:Membrane Potentials; D015221:Potassium Channels / Q000502:physiology*
chemical_list: D015221:Potassium Channels