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Ashrafuzzaman M, Koeppe RE, Andersen OS. Intrinsic Lipid Curvature and Bilayer Elasticity as Regulators of Channel Function: A Comparative Single-Molecule Study. Int J Mol Sci 2024; 25:2758. [PMID: 38474005 PMCID: PMC10931550 DOI: 10.3390/ijms25052758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 02/13/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Perturbations in bilayer material properties (thickness, lipid intrinsic curvature and elastic moduli) modulate the free energy difference between different membrane protein conformations, thereby leading to changes in the conformational preferences of bilayer-spanning proteins. To further explore the relative importance of curvature and elasticity in determining the changes in bilayer properties that underlie the modulation of channel function, we investigated how the micelle-forming amphiphiles Triton X-100, reduced Triton X-100 and the HII lipid phase promoter capsaicin modulate the function of alamethicin and gramicidin channels. Whether the amphiphile-induced changes in intrinsic curvature were negative or positive, amphiphile addition increased gramicidin channel appearance rates and lifetimes and stabilized the higher conductance states in alamethicin channels. When the intrinsic curvature was modulated by altering phospholipid head group interactions, however, maneuvers that promote a negative-going curvature stabilized the higher conductance states in alamethicin channels but destabilized gramicidin channels. Using gramicidin channels of different lengths to probe for changes in bilayer elasticity, we found that amphiphile adsorption increases bilayer elasticity, whereas altering head group interactions does not. We draw the following conclusions: first, confirming previous studies, both alamethicin and gramicidin channels are modulated by changes in lipid bilayer material properties, the changes occurring in parallel yet differing dependent on the property that is being changed; second, isolated, negative-going changes in curvature stabilize the higher current levels in alamethicin channels and destabilize gramicidin channels; third, increases in bilayer elasticity stabilize the higher current levels in alamethicin channels and stabilize gramicidin channels; and fourth, the energetic consequences of changes in elasticity tend to dominate over changes in curvature.
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Affiliation(s)
- Mohammad Ashrafuzzaman
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA;
| | - Roger E. Koeppe
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA;
| | - Olaf S. Andersen
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA;
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Sarkar P, Chattopadhyay A. Membrane Dipole Potential: An Emerging Approach to Explore Membrane Organization and Function. J Phys Chem B 2022; 126:4415-4430. [PMID: 35696090 DOI: 10.1021/acs.jpcb.2c02476] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biological membranes are complex organized molecular assemblies of lipids and proteins that provide cells and membrane-bound intracellular organelles their individual identities by morphological compartmentalization. Membrane dipole potential originates from the electrostatic potential difference within the membrane due to the nonrandom arrangement (orientation) of amphiphile and solvent (water) dipoles at the membrane interface. In this Feature Article, we will focus on the measurement of dipole potential using electrochromic fluorescent probes and highlight interesting applications. In addition, we will focus on ratiometric fluorescence microscopic imaging technique to measure dipole potential in cellular membranes, a technique that can be used to address novel problems in cell biology which are otherwise difficult to address using available approaches. We envision that membrane dipole potential could turn out to be a convenient tool in exploring the complex interplay between membrane lipids and proteins and could provide novel insights in membrane organization and function.
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Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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Asandei A, Mereuta L, Schiopu I, Park Y, Luchian T. Teaching an old dog new tricks: A lipid membrane-based electric immunosensor for real-time probing of the spike S 1 protein subunit from SARS-CoV-2. Proteomics 2021; 22:e2100047. [PMID: 34586750 PMCID: PMC8646443 DOI: 10.1002/pmic.202100047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/09/2021] [Accepted: 09/24/2021] [Indexed: 11/29/2022]
Abstract
Fast, cheap, and easy to implement point‐of‐care testing for various pathogens constituted a game changer in past years due to its potential for early disease diagnosis. Herein, we report on the proof‐of‐concept of a simple method enabling in vitro detection of a structural spike protein subunit from the SARS‐CoV‐2 (S1) in aqueous samples. At the core of this discovery lies the well‐known paradigm of monitoring the capacitive current across a reconstituted zwitterionic lipid membrane subjected to a periodic transmembrane potential, followed by the real‐time spectral analysis enabling the extraction of the second harmonic of the capacitive current. Subsequent changes in the amplitude of this harmonic recorded during lipid membrane–S1 interactions were correlated with alterations induced in the inner membrane potential profile by the S1 protein subunit adsorption, and were shown to be augmented by ionic strength, the presence of a specific monoclonal antibody designed against the S1 subunit and the angiotensin‐converting enzyme 2 (ACE2) protein receptor, and uninhibited by the presence of other human serum proteins.
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Affiliation(s)
- Alina Asandei
- Sciences Department, Interdisciplinary Research Institute, Alexandru I. Cuza University, Iasi, Romania
| | - Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Irina Schiopu
- Sciences Department, Interdisciplinary Research Institute, Alexandru I. Cuza University, Iasi, Romania
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
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The Nanopore-Tweezing-Based, Targeted Detection of Nucleobases on Short Functionalized Peptide Nucleic Acid Sequences. Polymers (Basel) 2021; 13:polym13081210. [PMID: 33918592 PMCID: PMC8069169 DOI: 10.3390/polym13081210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 02/07/2023] Open
Abstract
The implication of nanopores as versatile components in dedicated biosensors, nanoreactors, or miniaturized sequencers has considerably advanced single-molecule investigative science in a wide range of disciplines, ranging from molecular medicine and nanoscale chemistry to biophysics and ecology. Here, we employed the nanopore tweezing technique to capture amino acid-functionalized peptide nucleic acids (PNAs) with α-hemolysin-based nanopores and correlated the ensuing stochastic fluctuations of the ionic current through the nanopore with the composition and order of bases in the PNAs primary structure. We demonstrated that while the system enables the detection of distinct bases on homopolymeric PNA or triplet bases on heteropolymeric strands, it also reveals rich insights into the conformational dynamics of the entrapped PNA within the nanopore, relevant for perfecting the recognition capability of single-molecule sequencing.
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Efimova SS, Ostroumova OS. The Disordering Effect of Plant Metabolites on Model Lipid Membranes of Various Thickness. ACTA ACUST UNITED AC 2020. [DOI: 10.1134/s1990519x2005003x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Efimova SS, Zakharova AA, Ostroumova OS. Alkaloids Modulate the Functioning of Ion Channels Produced by Antimicrobial Agents via an Influence on the Lipid Host. Front Cell Dev Biol 2020; 8:537. [PMID: 32695785 PMCID: PMC7339123 DOI: 10.3389/fcell.2020.00537] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/08/2020] [Indexed: 12/22/2022] Open
Abstract
It is widely recognized that an alteration in membrane physical properties induced by the adsorption of various drugs and biologically active compounds might greatly affect the functioning of peptides and proteins embedded in the membrane, in particular various ion channels. This study aimed to obtain deep insight into the diversity of the molecular mechanisms of membrane action of one of the most numerous and extremely important class of phytochemicals, the alkaloids. Protoalkaloids (derivatives of β-phenylethylamine, benzylamines, and colchicines), heterocyclic alkaloids (derivatives of purine, quinolysidine, piperidine, pyridine, quinoline, and isoquinoline), and steroid alkaloids were tested. We evaluated the effects of 22 compounds on lipid packing by investigating the thermotropic behavior of membrane lipids and the leakage of a fluorescent marker from unilamellar lipid vesicles. The alteration in the transmembrane distribution of the electrical potential was estimated by measuring the alkaloid induced changes in the boundary potential of planar lipid bilayers. We found that benzylamines, the chili pepper active components, capsaicin and dihydrocapsaicin, strongly affect not only the elastic properties of the lipid host, but also its electrostatics by dramatic decrease in membrane dipole potential. We concluded that the increase in the conductance and lifetime of gramicidin A channels induced by benzylamines was related to alteration in membrane dipole potential not to decrease in membrane stiffness. A sharp decrease in the lifetime of single ion pores induced by the antifungal lipopeptide syringomycin E, after addition of benzylamines and black pepper alkaloid piperine, was also mainly due to the reduction in dipole potential. At the same time, we showed that the disordering of membrane lipids in the presence of benzylamines and piperine plays a decisive role in the regulation of the conductance induced by the antifungal polyene macrolide antibiotic nystatin, while the inhibition of steady-state transmembrane current produced by the antimicrobial peptide cecropin A was attributed to both the dipole potential drop and membrane lipid disordering in the presence of pepper alkaloids. These data might lead to a better understanding of the biological activity of alkaloids, especially their action on voltage-gated and mechanosensitive ion channels in cell membranes.
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Affiliation(s)
- Svetlana S Efimova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anastasiia A Zakharova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Olga S Ostroumova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
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Fengycin induces ion channels in lipid bilayers mimicking target fungal cell membranes. Sci Rep 2019; 9:16034. [PMID: 31690786 PMCID: PMC6831686 DOI: 10.1038/s41598-019-52551-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022] Open
Abstract
The one-sided addition of fengycin (FE) to planar lipid bilayers mimicking target fungal cell membranes up to 0.1 to 0.5 μM in the membrane bathing solution leads to the formation of well-defined and well-reproducible single-ion channels of various conductances in the picosiemens range. FE channels were characterized by asymmetric conductance-voltage characteristic. Membranes treated with FE showed nonideal cationic selectivity in potassium chloride bathing solutions. The membrane conductance induced by FE increased with the second power of the lipopeptide aqueous concentration, suggesting that at least FE dimers are involved in the formation of conductive subunits. The pore formation ability of FE was not distinctly affected by the molecular shape of membrane lipids but strongly depended on the presence of negatively charged species in the bilayer. FE channels were characterized by weakly pronounced voltage gating. Small molecules known to modify the transmembrane distribution of electrical potential and the lateral pressure profile were used to modulate the channel-forming activity of FE. The observed effects of membrane modifiers were attributed to changes in lipid packing and lipopeptide oligomerization in the membrane.
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Efimova SS, Ostroumova OS. Mechanisms of Regulation of Amyloid-Induced Permeability of Model Lipid Membranes by Polyphenols. ACTA ACUST UNITED AC 2019. [DOI: 10.1134/s1990519x19040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Mereuta L, Asandei A, Schiopu I, Park Y, Luchian T. Nanopore-Assisted, Sequence-Specific Detection, and Single-Molecule Hybridization Analysis of Short, Single-Stranded DNAs. Anal Chem 2019; 91:8630-8637. [PMID: 31194518 DOI: 10.1021/acs.analchem.9b02080] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We report here on the ability of the α-hemolysin (α-HL) nanopore to achieve label-free, selective, and real-time detection of 15 nt long ssDNA fragments in solution, by exploiting their hybridization with freely added, polycationic peptides-functionalized PNAs. At the core of our work lies the paradigm that when PNAs and ssDNA are mixed together, the bulk concentration of free PNA decreases, depending upon the (mis)match degree between complementary strands and their relative concentrations. We demonstrate that the ssDNA sensing principle and throughput of the method are determined by the rate at which nonhybridized, polycationic peptides-functionalized PNA molecules arrive at the α-HL's vestibule entrance and thread into the nanopore. We found that with the application of a 30-fold salt gradient across the nanopore, the method enhances single-molecule detection sensitivity in the nanomolar range of ssDNA concentrations. This study demonstrates that the transmembrane potential-dependent unzip of single PNA-DNA duplexes at the α-HL's β-barrel entry permits discrimination between sequences that differ by one base pair.
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Affiliation(s)
| | | | | | - Yoonkyung Park
- Department of Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM) , Chosun University , Gwangju 61452 , Republic of Korea
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10
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Zakharova AA, Efimova SS, Schagina LV, Malev VV, Ostroumova OS. Blocking ion channels induced by antifungal lipopeptide syringomycin E with amide-linked local anesthetics. Sci Rep 2018; 8:11543. [PMID: 30069037 PMCID: PMC6070474 DOI: 10.1038/s41598-018-30077-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 07/24/2018] [Indexed: 11/22/2022] Open
Abstract
The effects of the amide-linked (lidocaine (LDC), mepivacaine (MPV), prilocaine (PLC)) and ester-bound local anesthetics (benzocaine (BZC), procaine (PRC), and tetracaine (TTC)) on the pore-forming activity of the antifungal lipopeptide syringomycin E (SRE) in lipid bilayers were studied. Independently on electrolyte concentration in the membrane bathing solution the observed changes in conductance of SRE channels agreed with the altered membrane dipole potential under the action of ester-bound local anesthetics. Effects of aminoamides in diluted and concentrated solutions were completely different. At 0.1 M KCl (pH 7.4) the effects of amide-linked anesthetics were in accordance with changes in the membrane surface potential, while at 2 M KCl aminoamides blocked ion passage through the SRE channels, leading to sharp reductions in pore conductance at negative voltages and 100-fold decreases in the channel lifetimes. The effects were not practically influenced by the membrane lipid composition. The interaction cooperativity implied the existence of specific binding sites for amide-bound anesthetics in SRE channels.
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Affiliation(s)
- Anastasiia A Zakharova
- Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky prospect, St. Petersburg, 194064, Russia
| | - Svetlana S Efimova
- Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky prospect, St. Petersburg, 194064, Russia
| | - Ludmila V Schagina
- Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky prospect, St. Petersburg, 194064, Russia
| | - Valery V Malev
- Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky prospect, St. Petersburg, 194064, Russia.,Saint Petersburg State University, Institute of Chemistry, 26 Universitetskii prospect, St. Petersburg, Petergof, 198504, Russia
| | - Olga S Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky prospect, St. Petersburg, 194064, Russia.
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Pearlstein RA, Dickson CJ, Hornak V. Contributions of the membrane dipole potential to the function of voltage-gated cation channels and modulation by small molecule potentiators. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:177-194. [PMID: 27836643 DOI: 10.1016/j.bbamem.2016.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/28/2016] [Accepted: 11/06/2016] [Indexed: 01/27/2023]
Abstract
The membrane dipole potential (Ψd) constitutes one of three electrical potentials generated by cell membranes. Ψd arises from the unfavorable parallel alignment of phospholipid and water dipoles, and varies in magnitude both longitudinally and laterally across the bilayer according to membrane composition and phospholipid packing density. In this work, we propose that dynamic counter-balancing between Ψd and the transmembrane potential (ΔΨm) governs the conformational state transitions of voltage-gated ion channels. Ψd consists of 1) static outer, and dynamic inner leaflet components (Ψd(extra) and Ψd(intra), respectively); and 2) a transmembrane component (ΔΨd(inner-outer)), ariing from differences in intra- and extracellular leaflet composition. Ψd(intra), which transitions between high and low energy states (Ψd(intra, high) and Ψd(intra, low)) as a function of channel conformation, is transduced by the pore domain. ΔΨd(inner-outer) is transduced by the voltage-sensing (VS) domain in summation with ΔΨm. Potentiation of voltage-gated ion channels is of interest for the treatment of cardiac, neuronal, and other disorders arising from inherited/acquired ion channel dysfunction. Potentiators are widely believed to alter the rates and voltage-dependencies of channel gating transitions by binding to pockets in the membrane-facing and other regions of ion channel targets. Here, we propose that potentiators alter Ψd(intra) and/or Ψd(extra), thereby increasing or decreasing the energy barriers governing channel gating transitions. We used quantum mechanical and molecular dynamics (MD) simulations to predict the overall Ψd-modulating effects of a series of published positive hERG potentiators partitioned into model DOPC bilayers. Our findings suggest a strong correlation between the magnitude of Ψd-lowering and positive hERG potentiation across the series.
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Affiliation(s)
- Robert A Pearlstein
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA.
| | - Callum J Dickson
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA
| | - Viktor Hornak
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA
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Two types of syringomycin E channels in sphingomyelin-containing bilayers. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 45:91-8. [DOI: 10.1007/s00249-015-1101-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 10/19/2015] [Accepted: 11/11/2015] [Indexed: 10/22/2022]
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Efimova SS, Zakharov VV, Ostroumova OS. Effects of dipole modifiers on channel-forming activity of amyloid and amyloid-like peptides in lipid bilayers. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s1990519x15030049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Modifiers of membrane dipole potentials as tools for investigating ion channel formation and functioning. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 315:245-97. [PMID: 25708465 DOI: 10.1016/bs.ircmb.2014.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrostatic fields generated on and within biological membranes play a fundamental role in key processes in cell functions. The role of the membrane dipole potential is of particular interest because of its powerful impact on membrane permeability and lipid-protein interactions, including protein insertion, oligomerization, and function. The membrane dipole potential is defined by the orientation of electric dipoles of lipid headgroups, fatty acid carbonyl groups, and membrane-adsorbed water. As a result, the membrane interior is several hundred millivolts more positive than the external aqueous phase. This potential decrease depends on the lipid, and especially sterol, composition of the membrane. The adsorption of certain electroneutral molecules known as dipole modifiers may also lead to significant changes in the magnitude of the potential decrease. These agents are widely used to study the effects of the dipole potential on membrane transport. This review presents a critical analysis of a variety of data from studies dedicated to ion channel formation and functioning in membranes with different dipole potentials. The types of ion channels found in cellular membranes and pores formed by antimicrobial agents and toxins in artificial lipid membranes are summarized. The mechanisms underlying the influence of the membrane dipole potential on ion channel activity, including dipole-dipole and charge-dipole interactions in the pores and in membranes, are discussed. A hypothesis, in which lipid rafts in both model and cellular membranes also modulate ion channel activity by virtue of an increased or decreased dipole potential, is also considered.
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Efimova SS, Schagina LV, Ostroumova OS. Investigation of channel-forming activity of polyene macrolide antibiotics in planar lipid bilayers in the presence of dipole modifiers. Acta Naturae 2014; 6:67-79. [PMID: 25558397 PMCID: PMC4273094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The role of membrane components, sterols, phospholipids and sphingolipids in the formation and functioning of ion-permeable nanopores formed by antifungal macrolide antibiotics, amphotericin B, nystatin and filipin in planar lipid bilayers was studied. Dipole modifiers, flavonoids and styryl dyes, were used as a tool to study the molecular mechanisms of polyene channel-forming activity. The introduction of dipole modifiers into the membrane bathing solutions was shown to change the conductance of single channels and the steadystate transmembrane current induced by polyene antibiotics in the sterol-containing phospholipid-bilayers. The conductance of single amphotericin B channels was found to depend on the dipole potential of the membrane. The experiments with various phospholipids, sterols, and polyenes led to the assumption that the shape of a phospholipid molecule, the presence of double bonds at the positions 7 and 22 of a sterol molecule, the number of conjugated double bonds, and the presence of an amino sugar in the polyene antibiotic molecule are important factors impacting the stability of polyene-lipid complexes forming ion-permeable pores. Experimental and literature data presented in the paper suggest that the channel-forming activity of polyene antibiotics is also affected by the physicochemical properties of polyene-enriched ordered membrane domains.
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Affiliation(s)
- S. S. Efimova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave., 4, St. Petersburg, 194064, Russia
| | - L. V. Schagina
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave., 4, St. Petersburg, 194064, Russia
| | - O. S. Ostroumova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave., 4, St. Petersburg, 194064, Russia
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The influence of halogen derivatives of thyronine and fluorescein on the dipole potential of phospholipid membranes. J Membr Biol 2014; 247:739-45. [PMID: 25024118 DOI: 10.1007/s00232-014-9703-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/27/2014] [Indexed: 10/25/2022]
Abstract
The effects of halogen derivatives of thyronine (tetraiodotironine and triiodothyronine) and fluorescein (Rose Bengal, phloxine B, erythrosin, eosin Y, and fluorescein) on the dipole potential of membranes composed of diphytanoylphosphocholine, diphytanoylphosphoserine, and diphytanoylphosphoethanolamine were investigated. A quantitative description of the modifying action of the agents was presented as characteristic parameters of the Langmuir adsorption isotherm: the maximum changes in the dipole potential of the membrane at an infinitely high concentration of modifiers and the desorption constant, characterizing their inverse affinities to the lipid phase. It was shown that the iodine-containing hormones led to a less significant reduction in the dipole potential of phospholipid membranes compared to the xanthene dyes, Rose Bengal, phloxine B, and erythrosin. The latter were characterized by the highest affinity for the lipid membranes compared to tetraiodotironine and triiodothyronine. It was found that the effect of iodine-containing hormones and xanthene dyes on the membrane dipole potential was caused by their uncharged and charged forms, respectively.
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The interaction of dipole modifiers with amphotericin-ergosterol complexes. Effects of phospholipid and sphingolipid membrane composition. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:207-15. [DOI: 10.1007/s00249-014-0946-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/30/2014] [Accepted: 02/05/2014] [Indexed: 10/25/2022]
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18
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Kredics L, Szekeres A, Czifra D, Vágvölgyi C, Leitgeb B. Recent results in alamethicin research. Chem Biodivers 2013; 10:744-71. [PMID: 23681724 DOI: 10.1002/cbdv.201200390] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Indexed: 12/20/2022]
Affiliation(s)
- László Kredics
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726 Szeged.
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Ostroumova OS, Efimova SS, Chulkov EG, Schagina LV. The interaction of dipole modifiers with polyene-sterol complexes. PLoS One 2012; 7:e45135. [PMID: 23028805 PMCID: PMC3448605 DOI: 10.1371/journal.pone.0045135] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 08/13/2012] [Indexed: 11/18/2022] Open
Abstract
Recently, we showed that the effect of dipole modifiers (flavonoids and styrylpyridinium dyes) on the conductance of single amphotericin B (AmB) channels in sterol-containing lipid bilayers primarily resulted from changes in the membrane dipole potential. The present study examines the effect of dipole modifiers on the AmB multi-channel activity. The addition of phloretin to cholesterol-containing membranes leads to a significant increase in the steady-state AmB-induced transmembrane current. Quercetin significantly decreases and RH 421 increases the current through ergosterol-containing bilayers. Other tested flavonoids and styrylpyridinium dyes do not affect the channel-forming activity of AmB independently on the sterol composition of the bilayers. The effects obtained in these trials may instead be attributed to the direct interaction of dipole modifiers with AmB/sterol complexes and not to the effect of dipole potential changes. The presence of double bonds in the Δ7 and Δ22 positions of sterol molecules, the number of conjugated double bonds and amino sugar residues in polyene molecules, and the conformation and adsorption plane of dipole modifiers are important factors impacting this interaction.
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Affiliation(s)
- Olga S Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia.
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Aliverdieva D, Mamaev D, Snezhkova L, Sholtz C. Evaluation of molecularity of rate-limiting step of pore formation by antimicrobial peptides studied using mitochondria as a biosensor. Toxicol In Vitro 2012; 26:939-49. [DOI: 10.1016/j.tiv.2012.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 03/09/2012] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
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