title: Salt-Excluding Artificial Water Channels Exhibiting Enhanced Dipolar Water and Proton Translocation.
abstract: Aquaporins (AQPs) are biological water channels known for fast water transport (∼10(8)-10(9) molecules/s/channel) with ion exclusion. Few synthetic channels have been designed to mimic this high water permeability, and none reject ions at a significant level. Selective water translocation has previously been shown to depend on water-wires spanning the AQP pore that reverse their orientation, combined with correlated channel motions. No quantitative correlation between the dipolar orientation of the water-wires and their effects on water and proton translocation has been reported. Here, we use complementary X-ray structural data, bilayer transport experiments, and molecular dynamics (MD) simulations to gain key insights and quantify transport. We report artificial imidazole-quartet water channels with 2.6 Å pores, similar to AQP channels, that encapsulate oriented dipolar water-wires in a confined chiral conduit. These channels are able to transport ∼10(6) water molecules/s, which is within 2 orders of magnitude of AQPs' rates, and reject all ions except protons. The proton conductance is high (∼5 H(+)/s/channel) and approximately half that of the M2 proton channel at neutral pH. Chirality is a key feature influencing channel efficiency.
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Europeen des Membranes , ENSCM-UMII-UMR CNRS 5635, Place Eugene Bataillon CC047, Montpellier, F-34095, France.
authors.forename: Erol
authors.initials: E
authors.lastname: Licsandru
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Europeen des Membranes , ENSCM-UMII-UMR CNRS 5635, Place Eugene Bataillon CC047, Montpellier, F-34095, France.
authors.forename: Istvan
authors.initials: I
authors.lastname: Kocsis
authors.affiliation: Department of Chemical Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Yue-Xiao
authors.initials: YX
authors.lastname: Shen
authors.affiliation: Laboratoire de Biochimie Théorique, CNRS UPR 9080, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, F-75005 Paris, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Murail
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Europeen des Membranes , ENSCM-UMII-UMR CNRS 5635, Place Eugene Bataillon CC047, Montpellier, F-34095, France.
authors.forename: Yves-Marie
authors.initials: YM
authors.lastname: Legrand
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Europeen des Membranes , ENSCM-UMII-UMR CNRS 5635, Place Eugene Bataillon CC047, Montpellier, F-34095, France.
authors.forename: Arie
authors.initials: A
authors.lastname: van der Lee
authors.affiliation: Department of Chemical Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tsai
authors.affiliation: Laboratoire de Biochimie Théorique, CNRS UPR 9080, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, F-75005 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Baaden
authors.affiliation: Department of Chemical Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Manish
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Adaptive Supramolecular Nanosystems Group, Institut Europeen des Membranes , ENSCM-UMII-UMR CNRS 5635, Place Eugene Bataillon CC047, Montpellier, F-34095, France.
authors.forename: Mihail
authors.initials: M
authors.lastname: Barboiu