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Queralt-Martín M, Pérez-Grau JJ, Alvero González LM, Perini DA, Cervera J, Aguilella VM, Alcaraz A. Biphasic concentration patterns in ionic transport under nanoconfinement revealed in steady-state and time-dependent properties. J Chem Phys 2023; 158:064701. [PMID: 36792514 DOI: 10.1063/5.0136668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Ion permeation across nanoscopic structures differs considerably from microfluidics because of strong steric constraints, transformed solvent properties, and charge-regulation effects revealed mostly in diluted solutions. However, little is known about nanofluidics in moderately concentrated solutions, which are critically important for industrial applications and living systems. Here, we show that nanoconfinement triggers general biphasic concentration patterns in a myriad of ion transport properties by using two contrasting systems: a biological ion channel and a much larger synthetic nanopore. Our findings show a low-concentration regime ruled by classical Debye screening and another one where ion-ion correlations and enhanced ion-surface interactions contribute differently to each electrophysiological property. Thus, different quantities (e.g., conductance vs noise) measured under the same conditions may appear contradictory because they belong to different concentration regimes. In addition, non-linear effects that are barely visible in bulk conductivity only in extremely concentrated solutions become apparent in nanochannels around physiological conditions.
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Affiliation(s)
- María Queralt-Martín
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
| | - José J Pérez-Grau
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
| | - Laidy M Alvero González
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
| | - D Aurora Perini
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
| | - Javier Cervera
- Departament de Física de la Terra i Termodinàmica, Universitat de València, E-46100 Burjassot, Spain
| | - Vicente M Aguilella
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
| | - Antonio Alcaraz
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, E-12071 Castellón, Spain
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2
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Alkhadra M, Su X, Suss ME, Tian H, Guyes EN, Shocron AN, Conforti KM, de Souza JP, Kim N, Tedesco M, Khoiruddin K, Wenten IG, Santiago JG, Hatton TA, Bazant MZ. Electrochemical Methods for Water Purification, Ion Separations, and Energy Conversion. Chem Rev 2022; 122:13547-13635. [PMID: 35904408 PMCID: PMC9413246 DOI: 10.1021/acs.chemrev.1c00396] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Agricultural development, extensive industrialization, and rapid growth of the global population have inadvertently been accompanied by environmental pollution. Water pollution is exacerbated by the decreasing ability of traditional treatment methods to comply with tightening environmental standards. This review provides a comprehensive description of the principles and applications of electrochemical methods for water purification, ion separations, and energy conversion. Electrochemical methods have attractive features such as compact size, chemical selectivity, broad applicability, and reduced generation of secondary waste. Perhaps the greatest advantage of electrochemical methods, however, is that they remove contaminants directly from the water, while other technologies extract the water from the contaminants, which enables efficient removal of trace pollutants. The review begins with an overview of conventional electrochemical methods, which drive chemical or physical transformations via Faradaic reactions at electrodes, and proceeds to a detailed examination of the two primary mechanisms by which contaminants are separated in nondestructive electrochemical processes, namely electrokinetics and electrosorption. In these sections, special attention is given to emerging methods, such as shock electrodialysis and Faradaic electrosorption. Given the importance of generating clean, renewable energy, which may sometimes be combined with water purification, the review also discusses inverse methods of electrochemical energy conversion based on reverse electrosorption, electrowetting, and electrokinetic phenomena. The review concludes with a discussion of technology comparisons, remaining challenges, and potential innovations for the field such as process intensification and technoeconomic optimization.
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Affiliation(s)
- Mohammad
A. Alkhadra
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Xiao Su
- Department
of Chemical and Biomolecular Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Matthew E. Suss
- Faculty
of Mechanical Engineering, Technion—Israel
Institute of Technology, Haifa 3200003, Israel,Wolfson
Department of Chemical Engineering, Technion—Israel
Institute of Technology, Haifa 3200003, Israel,Nancy
and Stephen Grand Technion Energy Program, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Huanhuan Tian
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Eric N. Guyes
- Faculty
of Mechanical Engineering, Technion—Israel
Institute of Technology, Haifa 3200003, Israel
| | - Amit N. Shocron
- Faculty
of Mechanical Engineering, Technion—Israel
Institute of Technology, Haifa 3200003, Israel
| | - Kameron M. Conforti
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - J. Pedro de Souza
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Nayeong Kim
- Department
of Chemical and Biomolecular Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Michele Tedesco
- European
Centre of Excellence for Sustainable Water Technology, Wetsus, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Khoiruddin Khoiruddin
- Department
of Chemical Engineering, Institut Teknologi
Bandung, Jl. Ganesha no. 10, Bandung, 40132, Indonesia,Research
Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung 40132, Indonesia
| | - I Gede Wenten
- Department
of Chemical Engineering, Institut Teknologi
Bandung, Jl. Ganesha no. 10, Bandung, 40132, Indonesia,Research
Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung 40132, Indonesia
| | - Juan G. Santiago
- Department
of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - T. Alan Hatton
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Martin Z. Bazant
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States,Department
of Mathematics, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States,
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3
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Transport mechanisms of SARS-CoV-E viroporin in calcium solutions: Lipid-dependent Anomalous Mole Fraction Effect and regulation of pore conductance. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183590. [PMID: 33621516 PMCID: PMC7896491 DOI: 10.1016/j.bbamem.2021.183590] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 02/06/2023]
Abstract
The envelope protein E of the SARS-CoV coronavirus is an archetype of viroporin. It is a small hydrophobic protein displaying ion channel activity that has proven highly relevant in virus-host interaction and virulence. Ion transport through E channel was shown to alter Ca2+ homeostasis in the cell and trigger inflammation processes. Here, we study transport properties of the E viroporin in mixed solutions of potassium and calcium chloride that contain a fixed total concentration (mole fraction experiments). The channel is reconstituted in planar membranes of different lipid compositions, including a lipid mixture that mimics the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) membrane where the virus localizes within the cell. We find that the E ion conductance changes non-monotonically with the total ionic concentration displaying an Anomalous Mole Fraction Effect (AMFE) only when charged lipids are present in the membrane. We also observe that E channel insertion in ERGIC-mimic membranes – including lipid with intrinsic negative curvature – enhances ion permeation at physiological concentrations of pure CaCl2 or KCl solutions, with a preferential transport of Ca2+ in mixed KCl-CaCl2 solutions. Altogether, our findings demonstrate that the presence of calcium modulates the transport properties of the E channel by interacting preferentially with charged lipids through different mechanisms including direct Coulombic interactions and possibly inducing changes in membrane morphology.
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4
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Queralt-Martín M, López ML, Aguilella-Arzo M, Aguilella VM, Alcaraz A. Scaling Behavior of Ionic Transport in Membrane Nanochannels. NANO LETTERS 2018; 18:6604-6610. [PMID: 30178677 PMCID: PMC6242701 DOI: 10.1021/acs.nanolett.8b03235] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Ionic conductance in membrane channels exhibits a power-law dependence on electrolyte concentration ( G ∼ cα). The many scaling exponents, α, reported in the literature usually require detailed interpretations concerning each particular system under study. Here, we critically evaluate the predictive power of scaling exponents by analyzing conductance measurements in four biological channels with contrasting architectures. We show that scaling behavior depends on several interconnected effects whose contributions change with concentration so that the use of oversimplified models missing critical factors could be misleading. In fact, the presence of interfacial effects could give rise to an apparent universal scaling that hides the channel distinctive features. We complement our study with 3D structure-based Poisson-Nernst-Planck (PNP) calculations, giving results in line with experiments and validating scaling arguments. Our findings not only provide a unified framework for the study of ion transport in confined geometries but also highlight that scaling arguments are powerful and simple tools with which to offer a comprehensive perspective of complex systems, especially those in which the actual structure is unknown.
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Affiliation(s)
- María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver
NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - M. Lidón López
- Laboratory of Molecular Biophysics, Department of Physics,
Universitat Jaume I, Av. Vicent Sos Baynat s/n 12071 Castellón, Spain
| | - Marcel Aguilella-Arzo
- Laboratory of Molecular Biophysics, Department of Physics,
Universitat Jaume I, Av. Vicent Sos Baynat s/n 12071 Castellón, Spain
| | - Vicente M. Aguilella
- Laboratory of Molecular Biophysics, Department of Physics,
Universitat Jaume I, Av. Vicent Sos Baynat s/n 12071 Castellón, Spain
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics, Department of Physics,
Universitat Jaume I, Av. Vicent Sos Baynat s/n 12071 Castellón, Spain
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5
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Yousefpour A, Amjad-Iranagh S, Goharpey F, Modarress H. Effect of drug amlodipine on the charged lipid bilayer cell membranes DMPS and DMPS + DMPC: a molecular dynamics simulation study. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:939-950. [PMID: 29971510 DOI: 10.1007/s00249-018-1317-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/19/2018] [Accepted: 06/26/2018] [Indexed: 01/03/2023]
Abstract
In this work, the effects of the anti-hypertensive drug amlodipine in native and PEGylated forms on the malfunctioning of negatively charged lipid bilayer cell membranes constructed from DMPS or DMPS + DMPC were studied by molecular dynamics simulation. The obtained results indicate that amlodipine alone aggregates and as a result its diffusion into the membrane is retarded. In addition, due to their large size aggregates of the drug can damage the cell, rupturing the cell membrane. It is shown that PEGylation of amlodipine prevents this aggregation and facilitates its diffusion into the lipid membrane. The interaction of the drug with negatively charged membranes in the presence of an aqueous solution of NaCl, as the medium, is investigated and its effects on the membrane are considered by evaluating the structural properties of the membrane such as area per lipid, thickness, lipid chain order and electrostatic potential difference between bulk solution and lipid bilayer surface. The effect of these parameters on the diffusion of the drug into the cell is critically examined and discussed.
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Affiliation(s)
- Abbas Yousefpour
- Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, Tehran, P.O. Box 15875-4413, Iran
| | - Sepideh Amjad-Iranagh
- Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, Tehran, P.O. Box 15875-4413, Iran
| | - Fatemeh Goharpey
- Department of Polymer Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Hamid Modarress
- Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, Tehran, P.O. Box 15875-4413, Iran.
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6
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Apel PY, Bashevoy VV, Blonskaya IV, Lizunov NE, Orelovitch OL, Trautmann C. Shedding light on the mechanism of asymmetric track etching: an interplay between latent track structure, etchant diffusion and osmotic flow. Phys Chem Chem Phys 2018; 18:25421-25433. [PMID: 27722562 DOI: 10.1039/c6cp05465j] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The method of producing single track-etched conical nanopores has received considerable attention and found many applications in diverse fields such as biosensing, nanofluidics, information processing and others. The performance of an asymmetric nanopore is largely determined by its geometry, especially by the size and shape of its tip. In this paper we reconstruct the profiles of so-called conical pores fabricated by asymmetric chemical etching of ion tracks in polymer foil. Conductometric measurements during etching and field emission scanning electron microscopy examinations of the resulting pores were employed in order to determine the pore geometry. We demonstrate that the pore constriction geometry evolves through a variety of configurations with advancing time after breakthrough. While immediately after breakthrough the pore tips are trumpet-shaped, further etching is strongly affected by osmotic effects which eventually lead to bullet-shaped pore tips. We evidence that the osmotic flow appearing during asymmetric track etching has a determinative effect on pore formation. A convection-diffusion model is presented that semi-quantitatively explains the effect of osmotic processes under asymmetric track etching conditions. In addition, a phenomenon of reagent contaminant precipitation in nanopores is reported and discussed.
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Affiliation(s)
- Pavel Y Apel
- Joint Institute for Nuclear Research, Joliot-Curie Street 6, 141980 Dubna, Russian Federation. and Dubna State University, Universitetskaya Street 19, 141980 Dubna, Russian Federation
| | - Valery V Bashevoy
- Joint Institute for Nuclear Research, Joliot-Curie Street 6, 141980 Dubna, Russian Federation.
| | - Irina V Blonskaya
- Joint Institute for Nuclear Research, Joliot-Curie Street 6, 141980 Dubna, Russian Federation.
| | - Nikolay E Lizunov
- Joint Institute for Nuclear Research, Joliot-Curie Street 6, 141980 Dubna, Russian Federation.
| | - Oleg L Orelovitch
- Joint Institute for Nuclear Research, Joliot-Curie Street 6, 141980 Dubna, Russian Federation.
| | - Christina Trautmann
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany and Materialwissenschaft, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt, Germany
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7
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Apel PY, Blonskaya IV, Lizunov NE, Olejniczak K, Orelovitch OL, Sartowska BA, Dmitriev SN. Asymmetrical nanopores in track membranes: Fabrication, the effect of nanopore shape and electric charge of pore walls, promising applications. RUSS J ELECTROCHEM+ 2017. [DOI: 10.1134/s1023193517010037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Queralt-Martín M, Peiró-González C, Aguilella-Arzo M, Alcaraz A. Effects of extreme pH on ionic transport through protein nanopores: the role of ion diffusion and charge exclusion. Phys Chem Chem Phys 2016; 18:21668-75. [DOI: 10.1039/c6cp04180a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We combine electrophysiological experiments with the structure-based Poisson–Nernst–Planck 3D calculations to investigate the transport properties of the bacterial porin OmpF under large pH gradients and particularly low salt concentrations.
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Affiliation(s)
| | | | | | - Antonio Alcaraz
- Laboratory of Molecular Biophysics
- Department of Physics
- 12071 Castellón
- Spain
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9
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Dan N. Compound release from core–shell carriers triggered by oscillating fields: Monte Carlo simulations. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.04.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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10
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Drug release through liposome pores. Colloids Surf B Biointerfaces 2015; 126:80-6. [DOI: 10.1016/j.colsurfb.2014.11.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/23/2014] [Accepted: 11/25/2014] [Indexed: 11/19/2022]
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11
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Maffeo C, Bhattacharya S, Yoo J, Wells D, Aksimentiev A. Modeling and simulation of ion channels. Chem Rev 2012; 112:6250-84. [PMID: 23035940 PMCID: PMC3633640 DOI: 10.1021/cr3002609] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Christopher Maffeo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Swati Bhattacharya
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Jejoong Yoo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - David Wells
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
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12
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Queralt-Martín M, García-Giménez E, Mafé S, Alcaraz A. Divalent cations reduce the pH sensitivity of OmpF channel inducing the pKashift of key acidic residues. Phys Chem Chem Phys 2011; 13:563-9. [DOI: 10.1039/c0cp01325k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Aguilella VM, Queralt-Martín M, Aguilella-Arzo M, Alcaraz A. Insights on the permeability of wide protein channels: measurement and interpretation of ion selectivity. Integr Biol (Camb) 2010; 3:159-72. [PMID: 21132209 DOI: 10.1039/c0ib00048e] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion channels are hollow proteins that have evolved to exhibit discrimination between charged solutes. This property, known as ion selectivity is critical for several biological functions. By using the bacterial porin OmpF as a model system of wide protein channels, we demonstrate that significant insights can be gained when selectivity measurements are combined with electrodiffusion continuum models and simulations based on the atomic structure. A correct interpretation of the mechanisms ruling the many sources of channel discrimination is a first, indispensable step for the understanding of the controlled movement of ions into or out of cells characteristic of many physiological processes. We conclude that the scattered information gathered from several independent approaches should be appropriately merged to provide a unified and coherent picture of the channel selectivity.
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Affiliation(s)
- Vicente M Aguilella
- Dept. Physics, Lab. Molecular Biophysics, Universitat Jaume I, 12080 Castellón, Spain.
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14
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García-Giménez E, López ML, Aguilella VM, Alcaraz A. Linearity, saturation and blocking in a large multiionic channel: divalent cation modulation of the OmpF porin conductance. Biochem Biophys Res Commun 2010; 404:330-4. [PMID: 21134352 DOI: 10.1016/j.bbrc.2010.11.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 11/27/2010] [Indexed: 11/16/2022]
Abstract
Measurement of unitary conductance is a fundamental step in the characterization of a protein ion channel permeabilizing a membrane. We study here the effect of salts of divalent cations on the OmpF channel conductance with a particular emphasis in dissecting the role of the electrolyte itself, the role of the counterion accumulation induced by the protein channel charges and other effects not found in salts of monovalent cations. We show that current saturation and blocking are not exclusive properties of narrow (single-file) ion channels but may be observed in large, multiionic channels like bacterial porins. Single-channel conductance measurements performed over a wide range of salt concentrations (up to 3 M) combined with continuum electrodiffusion calculations demonstrate that current saturation cannot be simply ascribed to ion interaction with protein channel residues.
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Affiliation(s)
- Elena García-Giménez
- Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, Av. Sos Baynat s/n, 12080 Castellón, Spain
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15
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López ML, García-Giménez E, Aguilella VM, Alcaraz A. Critical assessment of OmpF channel selectivity: merging information from different experimental protocols. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:454106. [PMID: 21339594 DOI: 10.1088/0953-8984/22/45/454106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The ion selectivity of a channel can be quantified in several ways by using different experimental protocols. A wide, mesoscopic channel, the OmpF porin of the outer membrane of E. coli, serves as a case study for comparing and analysing several measures of the channel cation-anion permeability in chlorides of alkali metals (LiCl, NaCl, KCl, CsCl). We show how different insights can be gained and integrated to rationalize the global image of channel selectivity. To this end, reversal potential, channel conductance and bi-ionic potential (two different salts with a common anion on each side of the channel but with the same concentration) experiments are discussed in light of an electrodiffusion model based on the Poisson-Nernst-Planck formalism. Measurements and calculations based on the atomic crystal structure of the channel show that each protocol displays a particular balance between the different sources of selectivity.
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Affiliation(s)
- M L López
- Department of Physics, Laboratory of Molecular Biophysics, Universitat Jaume I, Avenida Sos Baynat s/n, 12080 Castellón, Spain
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16
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López ML, Aguilella-Arzo M, Aguilella VM, Alcaraz A. Ion Selectivity of a Biological Channel at High Concentration Ratio: Insights on Small Ion Diffusion and Binding. J Phys Chem B 2009; 113:8745-51. [DOI: 10.1021/jp902267g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Lidón López
- Department of Physics, Laboratory of Molecular Biophysics, University Jaume I, Av. Sos Baynat, s/n, 12080 Castellón, Spain
| | - Marcel Aguilella-Arzo
- Department of Physics, Laboratory of Molecular Biophysics, University Jaume I, Av. Sos Baynat, s/n, 12080 Castellón, Spain
| | - Vicente M. Aguilella
- Department of Physics, Laboratory of Molecular Biophysics, University Jaume I, Av. Sos Baynat, s/n, 12080 Castellón, Spain
| | - Antonio Alcaraz
- Department of Physics, Laboratory of Molecular Biophysics, University Jaume I, Av. Sos Baynat, s/n, 12080 Castellón, Spain
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17
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Yameen B, Ali M, Neumann R, Ensinger W, Knoll W, Azzaroni O. Single Conical Nanopores Displaying pH-Tunable Rectifying Characteristics. Manipulating Ionic Transport With Zwitterionic Polymer Brushes. J Am Chem Soc 2009; 131:2070-1. [DOI: 10.1021/ja8086104] [Citation(s) in RCA: 314] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Basit Yameen
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
| | - Mubarak Ali
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
| | - Reinhard Neumann
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
| | - Wolfgang Ensinger
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
| | - Wolfgang Knoll
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
| | - Omar Azzaroni
- Max-Planck-Institut für Polymerforschung, Mainz, Germany, Technische Universität Darmstadt, Darmstadt, Germany, Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA) − CONICET − Universidad Nacional de La Plata, La Plata, Argentina
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18
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19
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Aguilella-Arzo M, Andrio A, Aguilella VM, Alcaraz A. Dielectric saturation of water in a membrane protein channel. Phys Chem Chem Phys 2009; 11:358-65. [DOI: 10.1039/b812775a] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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White HS, Bund A. Ion current rectification at nanopores in glass membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:2212-2218. [PMID: 18225931 DOI: 10.1021/la702955k] [Citation(s) in RCA: 264] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The origin of ion current rectification observed at conical-shaped nanopores in glass membranes immersed in KCl solutions has been investigated using finite-element simulations. The ion concentrations and fluxes (due to diffusion, migration, and electroosmotic convection) were determined by the simultaneous solution of the Nernst-Planck, Poisson, and Navier-Stokes equations for the two-ion (K+ and Cl-) system. Fixed surface charge on both the internal and external glass surfaces that define the pore structure was included to account for electric fields and nonuniform ion conductivity within the nanopores and electric fields in the external solution near the pore mouth. We demonstrate that previous observations of ion current rectification in conical-shaped glass nanopores are a consequence of the voltage-dependent solution conductivity in the vicinity of the pore mouth, both inside and outside of the pore. The simulations also demonstrate that current rectification is maximized at intermediate bulk ion concentrations, a combination of (i) the electrical screening of surface charge at high concentrations and (ii) a fixed number of charge-carrying ions in the pore at lower concentration, which are physical conditions where the voltage dependence of the conductivity disappears. In addition, we have quantitatively shown that electroosmotic flow gives rise to a significant but small contribution to current rectification.
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Affiliation(s)
- Henry S White
- University of Utah, Chemistry Department, Salt Lake City, Utah 84112, USA
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Abstract
Nanopores are extremely sensitive single-molecule sensors. Recently, electron beams have been used to fabricate synthetic nanopores in thin solid-state membranes with subnanometer resolution. Here we report a new class of chemically modified nanopore sensors. We describe two approaches for monolayer coating of nanopores: (1) self-assembly from solution, in which nanopores approximately 10 nm diameter can be reproducibly coated, and (2) self-assembly under voltage-driven electrolyte flow, in which we are able to coat 5 nm nanopores. We present an extensive characterization of coated nanopores, their stability, reactivity, and pH response.
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Affiliation(s)
- Meni Wanunu
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
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