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Volovik MV, Denieva ZG, Gifer PK, Rakitina MA, Batishchev OV. Membrane Activity and Viroporin Assembly for the SARS-CoV-2 E Protein Are Regulated by Cholesterol. Biomolecules 2024; 14:1061. [PMID: 39334828 PMCID: PMC11430671 DOI: 10.3390/biom14091061] [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: 07/17/2024] [Revised: 08/20/2024] [Accepted: 08/25/2024] [Indexed: 09/30/2024] Open
Abstract
The SARS-CoV-2 E protein is an enigmatic viral structural protein with reported viroporin activity associated with the acute respiratory symptoms of COVID-19, as well as the ability to deform cell membranes for viral budding. Like many viroporins, the E protein is thought to oligomerize with a well-defined stoichiometry. However, attempts to determine the structure of the protein complex have yielded inconclusive results, suggesting several possible oligomers, ranging from dimers to pentamers. Here, we combined patch-clamp, confocal fluorescence microscopy on giant unilamellar vesicles, and atomic force microscopy to show that E protein can exhibit two modes of membrane activity depending on membrane lipid composition. In the absence or the presence of a low content of cholesterol, the protein forms short-living transient pores, which are seen as semi-transmembrane defects in a membrane by atomic force microscopy. Approximately 30 mol% cholesterol is a threshold for the transition to the second mode of conductance, which could be a stable pentameric channel penetrating the entire lipid bilayer. Therefore, the E-protein has at least two different types of activity on membrane permeabilization, which are regulated by the amount of cholesterol in the membrane lipid composition and could be associated with different types of protein oligomers.
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Affiliation(s)
- Marta V Volovik
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia
| | - Zaret G Denieva
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia
| | - Polina K Gifer
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia
| | - Maria A Rakitina
- N.I. Pirogov Russian National Research Medical University of the Ministry of Health of the Russian Federation, 1 Ostrovityanova Street, 117997 Moscow, Russia
| | - Oleg V Batishchev
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia
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2
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Wei C, Pohorille A. Multi-oligomeric states of alamethicin ion channel: Assemblies and conductance. Biophys J 2023; 122:2531-2543. [PMID: 37161094 PMCID: PMC10323028 DOI: 10.1016/j.bpj.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/03/2023] [Accepted: 05/04/2023] [Indexed: 05/11/2023] Open
Abstract
Transmembrane assemblies of the peptaibol alamethicin (ALM) are among the most extensively studied ion channels not only because of their antimicrobial activity but also as models for channel structure and aggregation. In this study, several oligomeric states of ALM are investigated with molecular dynamics simulations to establish properties of the channel and obtain free energy profiles for ion transport and the corresponding values of conductance. The hexamer, heptamer, and octamer of ALM in phospholipid membrane are found to be stable but highly dynamic in barrel-stave structures, with calculated conductance equal to 18, 195, and 1270 pS, respectively, in 1 M KCl ion solution. The corresponding free energy profiles, reported for the first time, are reconstructed from simulations at applied voltage of 200 mV with the aid of the electrodiffusion model both with and without the knowledge of diffusivity. The calculated free energy barriers are equal to 2.5, 1.5, and 0.5 kcal/mol for K+ and 4.0, 2.2, and 1.5 kcal/mol for Cl-, for hexamer, heptamer, and octamer, respectively. The calculated conductance and the ratio between conductance in consecutive states are in good agreement with those measured experimentally. This suggests that the hexamer is the lowest conducting state, with measured conductance equal to 19 pS. The selectivity of K+ over Cl- is calculated as 1.5 and 2.3 for the octameric and heptameric channels, close to the selectivity measured for high-conductance states. Selectivity increases to 13 in the hexameric channel in which the narrowest Gln7 site has a pore radius of only ∼1.6 Å, again in accord with experiment. A good agreement found between calculated and measured conductance through a hexamer templated on cyclodextrin lands additional support for the results of our simulations, and the comparison with ALM reveals the dependence of conductance on the nature of phospholipid membrane.
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Affiliation(s)
- Chenyu Wei
- NASA Ames Research Center, Moffett Field, California; SETI Institute, Mountain View, California.
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3
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González-Magaña A, Altuna J, Queralt-Martín M, Largo E, Velázquez C, Montánchez I, Bernal P, Alcaraz A, Albesa-Jové D. The P. aeruginosa effector Tse5 forms membrane pores disrupting the membrane potential of intoxicated bacteria. Commun Biol 2022; 5:1189. [PMID: 36335275 PMCID: PMC9637101 DOI: 10.1038/s42003-022-04140-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 10/20/2022] [Indexed: 11/08/2022] Open
Abstract
The type VI secretion system (T6SS) of Pseudomonas aeruginosa injects effector proteins into neighbouring competitors and host cells, providing a fitness advantage that allows this opportunistic nosocomial pathogen to persist and prevail during the onset of infections. However, despite the high clinical relevance of P. aeruginosa, the identity and mode of action of most P. aeruginosa T6SS-dependent effectors remain to be discovered. Here, we report the molecular mechanism of Tse5-CT, the toxic auto-proteolytic product of the P. aeruginosa T6SS exported effector Tse5. Our results demonstrate that Tse5-CT is a pore-forming toxin that can transport ions across the membrane, causing membrane depolarisation and bacterial death. The membrane potential regulates a wide range of essential cellular functions; therefore, membrane depolarisation is an efficient strategy to compete with other microorganisms in polymicrobial environments.
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Affiliation(s)
- Amaia González-Magaña
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain
| | - Jon Altuna
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain
| | - María Queralt-Martín
- Laboratory of Molecular Biophysics, Department of Physics, University Jaume I, 12071, Castellón, Spain
| | - Eneko Largo
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain
- Departamento de Inmunología, Microbiología y Parasitología, University of the Basque Country, 48940, Leioa, Spain
| | - Carmen Velázquez
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain
| | - Itxaso Montánchez
- Departamento de Inmunología, Microbiología y Parasitología, University of the Basque Country, 48940, Leioa, Spain
| | - Patricia Bernal
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, 41012, Sevilla, Spain
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics, Department of Physics, University Jaume I, 12071, Castellón, Spain
| | - David Albesa-Jové
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain.
- Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain.
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Perini DA, Aguilella-Arzo M, Alcaraz A, Perálvarez-Marín A, Queralt-Martín M. Dynorphin A induces membrane permeabilization by formation of proteolipidic pores. Insights from electrophysiology and computational simulations. Comput Struct Biotechnol J 2022; 20:230-240. [PMID: 35024095 PMCID: PMC8718563 DOI: 10.1016/j.csbj.2021.12.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 01/14/2023] Open
Abstract
Dynorphins are endogenous neuropeptides that function as ligands for the κ-opioid receptor. In addition to opioid activity, dynorphins can induce several pathological effects such as neurological dysfunctions and cell death. Previous studies have suggested that Dynorphin A (DynA) mediates some pathogenic actions through formation of transient pores in lipid domains of the plasma membrane. Here, we use planar bilayer electrophysiology to show that DynA induces pore formation in negatively charged membranes. We find a large variability in pore conformations showing equilibrium conductance fluctuations, what disregards electroporation as the dominant mechanism of pore formation. Ion selectivity measurements showing cationic selectivity indicate that positive protein charges of DynA are stabilized by phosphatidyl serine negative charges in the formation of combined structures. We complement our study with computational simulations that assess the stability of diverse peptide arrangements in the hydrophobic core of the bilayer. We show that DynA is capable of assembling in charged membranes to form water-filled pores that conduct ions.
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Affiliation(s)
- D Aurora Perini
- Laboratory of Molecular Biophysics. Department of Physics. Universitat Jaume I, 12071 Castellón, Spain
| | - Marcel Aguilella-Arzo
- Laboratory of Molecular Biophysics. Department of Physics. Universitat Jaume I, 12071 Castellón, Spain
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics. Department of Physics. Universitat Jaume I, 12071 Castellón, Spain
| | - Alex Perálvarez-Marín
- Biophysics Unit, Department of Biochemistry and Molecular Biology, School of Medicine, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain.,Institute of Neuroscience, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - María Queralt-Martín
- Laboratory of Molecular Biophysics. Department of Physics. Universitat Jaume I, 12071 Castellón, Spain
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5
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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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6
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Largo E, Queralt-Martín M, Carravilla P, Nieva JL, Alcaraz A. Single-molecule conformational dynamics of viroporin ion channels regulated by lipid-protein interactions. Bioelectrochemistry 2020; 137:107641. [PMID: 32889489 PMCID: PMC7444495 DOI: 10.1016/j.bioelechem.2020.107641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/19/2020] [Accepted: 08/19/2020] [Indexed: 12/21/2022]
Abstract
Classic swine fever is a highly contagious and often fatal viral disease that is caused by the classical swine fever virus (CSFV). Protein p7 of CFSV is a prototype of viroporin, a family of small, highly hydrophobic proteins postulated to modulate virus-host interactions during the processes of virus entry, replication and assembly. It has been shown that CSFV p7 displays substantial ion channel activity when incorporated into membrane systems, but a deep rationalization of the size and dynamics of the induced pores is yet to emerge. Here, we use high-resolution conductance measurements and current fluctuation analysis to demonstrate that CSFV p7 channels are ruled by equilibrium conformational dynamics involving protein-lipid interactions. Atomic force microscopy (AFM) confirms the existence of a variety of pore sizes and their tight regulation by solution pH. We conclude that p7 viroporin forms subnanometric channels involved in virus propagation, but also much larger pores (1-10 nm in diameter) with potentially significant roles in virus pathogenicity. Our findings provide new insights into the sources of noise in protein electrochemistry and demonstrate the existence of slow complex dynamics characteristic of crowded systems like biomembrane surfaces.
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Affiliation(s)
- Eneko Largo
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain; Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa E-48940, Spain; Department of Immunology, Microbiology and Parasitology, Faculty of Medicine, University of the Basque Country (UPV/EHU), Leioa, Bizkaia, Spain
| | - María Queralt-Martín
- Laboratory of Molecular Biophysics, Department of Physics, University Jaume I, 12071 Castellón, Spain
| | - Pablo Carravilla
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain; Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa E-48940, Spain; Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Strasse 9, Jena, Germany
| | - José L Nieva
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain; Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa E-48940, Spain
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics, Department of Physics, University Jaume I, 12071 Castellón, Spain.
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7
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Das S, Ben Haj Salah K, Djibo M, Inguimbert N. Peptaibols as a model for the insertions of chemical modifications. Arch Biochem Biophys 2018; 658:16-30. [DOI: 10.1016/j.abb.2018.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/05/2018] [Accepted: 09/18/2018] [Indexed: 12/13/2022]
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8
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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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9
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Sekiya Y, Sakashita S, Shimizu K, Usui K, Kawano R. Channel current analysis estimates the pore-formation and the penetration of transmembrane peptides. Analyst 2018; 143:3540-3543. [DOI: 10.1039/c8an00243f] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We measured the current signal of the transmembrane model peptides using the barrel-stave, toroidal pore, and penetration models in order to establish a precise assignment of the channel signals.
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Affiliation(s)
- Yusuke Sekiya
- Department of Biotechnology and Life Science
- Tokyo University of Agriculture and Technology
- Tokyo 184-8588
- Japan
| | - Shungo Sakashita
- FIRST (Faculty of Frontiers of Innovative Research in Science and Technology)
- Konan University
- Kobe 650-0047
- Japan
| | - Keisuke Shimizu
- Department of Biotechnology and Life Science
- Tokyo University of Agriculture and Technology
- Tokyo 184-8588
- Japan
| | - Kenji Usui
- FIRST (Faculty of Frontiers of Innovative Research in Science and Technology)
- Konan University
- Kobe 650-0047
- Japan
| | - Ryuji Kawano
- Department of Biotechnology and Life Science
- Tokyo University of Agriculture and Technology
- Tokyo 184-8588
- Japan
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Salnikov ES, Raya J, De Zotti M, Zaitseva E, Peggion C, Ballano G, Toniolo C, Raap J, Bechinger B. Alamethicin Supramolecular Organization in Lipid Membranes from 19F Solid-State NMR. Biophys J 2017; 111:2450-2459. [PMID: 27926846 DOI: 10.1016/j.bpj.2016.09.048] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/10/2016] [Accepted: 09/29/2016] [Indexed: 11/24/2022] Open
Abstract
Alamethicins (ALMs) are antimicrobial peptides of fungal origin. Their sequences are rich in hydrophobic amino acids and strongly interact with lipid membranes, where they cause a well-defined increase in conductivity. Therefore, the peptides are thought to form transmembrane helical bundles in which the more hydrophilic residues line a water-filled pore. Whereas the peptide has been well characterized in terms of secondary structure, membrane topology, and interactions, much fewer data are available regarding the quaternary arrangement of the helices within lipid bilayers. A new, to our knowledge, fluorine-labeled ALM derivative was prepared and characterized when reconstituted into phospholipid bilayers. As a part of these studies, C19F3-labeled compounds were characterized and calibrated for the first time, to our knowledge, for 19F solid-state NMR distance and oligomerization measurements by centerband-only detection of exchange (CODEX) experiments, which opens up a large range of potential labeling schemes. The 19F-19F CODEX solid-state NMR experiments performed with ALM in POPC lipid bilayers and at peptide/lipid ratios of 1:13 are in excellent agreement with molecular-dynamics calculations of dynamic pentameric assemblies. When the peptide/lipid ratio was lowered to 1:30, ALM was found in the dimeric form, indicating that the supramolecular organization is tuned by equilibria that can be shifted by changes in environmental conditions.
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Affiliation(s)
- Evgeniy S Salnikov
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France
| | - Jesus Raya
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France
| | - Marta De Zotti
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Ekaterina Zaitseva
- Department of Membrane Physiology and Technology, Institute of Physiology, University of Freiburg, Freiburg, Germany
| | - Cristina Peggion
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Gema Ballano
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Claudio Toniolo
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Jan Raap
- Leiden Institute of Chemistry, Gorlaeus Laboratories, University of Leiden, Leiden, the Netherlands
| | - Burkhard Bechinger
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France.
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Marik T, Urbán P, Tyagi C, Szekeres A, Leitgeb B, Vágvölgyi M, Manczinger L, Druzhinina IS, Vágvölgyi C, Kredics L. Diversity Profile and Dynamics of Peptaibols Produced by Green Mould Trichoderma Species in Interactions with Their Hosts Agaricus bisporus and Pleurotus ostreatus. Chem Biodivers 2017; 14. [PMID: 28261948 DOI: 10.1002/cbdv.201700033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 02/27/2017] [Indexed: 11/06/2022]
Abstract
Certain Trichoderma species are causing serious losses in mushroom production worldwide. Trichoderma aggressivum and Trichoderma pleuroti are among the major causal agents of the green mould diseases affecting Agaricus bisporus and Pleurotus ostreatus, respectively. The genus Trichoderma is well-known for the production of bioactive secondary metabolites, including peptaibols, which are short, linear peptides containing unusual amino acid residues and being synthesised via non-ribosomal peptide synthetases (NRPSs). The aim of this study was to get more insight into the peptaibol production of T. aggressivum and T. pleuroti. HPLC/MS-based methods revealed the production of peptaibols closely related to hypomurocins B by T. aggressivum, while tripleurins representing a new group of 18-residue peptaibols were identified in T. pleuroti. Putative NRPS genes enabling the biosynthesis of the detected peptaibols could be found in the genomes of both Trichoderma species. In vitro experiments revealed that peptaibols are potential growth inhibitors of mushroom mycelia, and that the host mushrooms may have an influence on the peptaibol profiles of green mould agents.
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Affiliation(s)
- Tamás Marik
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Péter Urbán
- Department of General and Environmental Microbiology, Faculty of Sciences, and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, H-7624, Pécs, Hungary
| | - Chetna Tyagi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - András Szekeres
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Balázs Leitgeb
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Máté Vágvölgyi
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, H-6720, Szeged, Hungary
| | - László Manczinger
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Irina S Druzhinina
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, Getreidemarkt 9/166, A-1060, Vienna, Austria
| | - Csaba Vágvölgyi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - László Kredics
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
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12
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Si W, Xin P, Li ZT, Hou JL. Tubular Unimolecular Transmembrane Channels: Construction Strategy and Transport Activities. Acc Chem Res 2015; 48:1612-9. [PMID: 26017272 DOI: 10.1021/acs.accounts.5b00143] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lipid bilayer membranes separate living cells from their environment. Membrane proteins are responsible for the processing of ion and molecular inputs and exports, sensing stimuli and signals across the bilayers, which may operate in a channel or carrier mechanism. Inspired by these wide-ranging functions of membrane proteins, chemists have made great efforts in constructing synthetic mimics in order to understand the transport mechanisms, create materials for separation, and develop therapeutic agents. Since the report of an alkylated cyclodextrin for transporting Cu(2+) and Co(2+) by Tabushi and co-workers in 1982, chemists have constructed a variety of artificial transmembrane channels by making use of either the multimolecular self-assembly or unimolecular strategy. In the context of the design of unimolecular channels, important advances have been made, including, among others, the tethering of natural gramicidin A or alamethicin and the modification of various macrocycles such as crown ethers, cyclodextrins, calixarenes, and cucurbiturils. Many of these unimolecular channels exhibit high transport ability for metal ions, particularly K(+) and Na(+). Concerning the development of artificial channels based on macrocyclic frameworks, one straightforward and efficient approach is to introduce discrete chains to reinforce their capability to insert into bilayers. Currently, this approach has found the widest applications in the systems of crown ethers and calixarenes. We envisioned that for macrocycle-based unimolecular channels, control of the arrangement of the appended chains in the upward and/or downward direction would favor the insertion of the molecular systems into bilayers, while the introduction of additional interactions among the chains would further stabilize a tubular conformation. Both factors should be helpful for the formation of new efficient channels. In this Account, we discuss our efforts in designing new unimolecular artificial channels from tubular pillar[n]arenes by extending their lengths with various ester, hydrazide, and short peptide chains. We have utilized well-defined pillar[5]arene and pillar[6]arene as rigid frameworks that allow the appended chains to afford extended tubular structures. We demonstrate that the hydrazide and peptide chains form intramolecular N-H···O═C hydrogen bonds that enhance the tubular conformation of the whole molecule. The new pillar[n]arene derivatives have been successfully applied as unimolecular channels for the selective transport of protons, water, and amino acids and the voltage-gated transport of K(+). We also show that aromatic hydrazide helices and macrocycles appended with peptide chains are able to mediate the selective transport of NH4(+).
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Affiliation(s)
- Wen Si
- Department
of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
| | - Pengyang Xin
- Department
of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
| | - Zhan-Ting Li
- Department
of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
| | - Jun-Li Hou
- Department
of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
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De Zotti M, Ballano G, Jost M, Salnikov ES, Bechinger B, Oancea S, Crisma M, Toniolo C, Formaggio F. Solution synthesis, conformational analysis, and antimicrobial activity of three alamethicin F50/5 analogs bearing a trifluoroacetyl label. Chem Biodivers 2015; 11:1163-91. [PMID: 25146762 DOI: 10.1002/cbdv.201300394] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Indexed: 11/07/2022]
Abstract
We prepared, by solution-phase methods, and fully characterized three analogs of the membrane-active peptaibiotic alamethicin F50/5, bearing a single trifluoroacetyl (Tfa) label at the N-terminus, at position 9 (central region) or at position 19 (C-terminus), and with the three Gln at positions 7, 18, and 19 replaced by Glu(OMe) residues. To add the Tfa label at position 9 or 19, a γ-trifluoroacetylated α,γ-diaminobutyric acid (Dab) residue was incorporated as a replacement for the original Val(9) or Glu(OMe)(19) amino acid. We performed a detailed conformational analysis of the three analogs (using FT-IR absorption, CD, 2D-NMR, and X-ray diffraction), which clearly showed that Tfa labeling does not introduce any dramatic backbone modification in the predominantly α-helical structure of the parent peptaibiotic. The results of an initial solid-state (19)F-NMR study on one of the analogs favor the conclusion that the Tfa group is a very promising reporter for the analysis of peptaibioticmembrane interactions. Finally, we found that the antimicrobial activities of the three newly synthesized analogs depend on the position of the Tfa label in the peptide sequence.
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Affiliation(s)
- Marta De Zotti
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, I-35131 Padova.
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14
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Rahaman A, Lazaridis T. A thermodynamic approach to alamethicin pore formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014. [DOI: 10.1016/j.bbamem.2014.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Futaki S, Noshiro D, Kiwada T, Asami K. Extramembrane control of ion channel peptide assemblies, using alamethicin as an example. Acc Chem Res 2013; 46:2924-33. [PMID: 23680081 DOI: 10.1021/ar400051f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ion channels allow the influx and efflux of specific ions through a plasma membrane. Many ion channels can sense, for example, the membrane potential (the voltage gaps between the inside and the outside of the membrane), specific ligands such as neurotransmitters, and mechanical tension within the membrane. They modulate cell function in response to these stimuli. Researchers have focused on developing peptide- and non-peptide-based model systems to elucidate ion-channel protein functions and to create artificial sensing systems. In this Account, we employed a typical peptide that forms ion channels,alamethicin, as a model to evaluate our methodologies for controlling the assembly states of channel-forming molecules in membranes. As alamethicin self-assembles in membranes, it prompts channel formation, but number of peptide molecules in these channels is not constant. Using planar-lipid bilayer methods, we monitored the association states of alamethicin in real time. Many ligand-gated, natural-ion channel proteins have large extramembrane domains. As these proteins interact with specific ligands, those conformational alterations in the extramembrane domains are transmitted to the transmembrane, pore-forming domains to open and close the channels. We hypothesized that if we conjugated suitable extramembrane segments to alamethicin, ligand binding to the extramembrane segments could alter the structure of the extramembrane domains and influence the association states or association numbers of alamethicin in the membranes. We could then assess those changes by using single-channel current recording. We found that we could modulate channel assembly and eventual ion flux with attached leucine-zipper extramembrane peptide segments. Using conformationally switchable leucine-zipper extramembrane segments that respond to Fe(3+), we fabricated an artificial Fe(3+)-sensitive ion channel; a decrease in the helical content of the extramembrane segment led to an increase in the channel current. When we added a calmodulin C-terminus segment, we formed a channel that was sensitive to Ca(2+). This result demonstrated that we could prepare artificial channels that were sensitive to specific ligands by adding appropriate extramembrane segments from natural protein motifs that respond to external stimuli. In conclusion, our research points to the possibility of creating tailored sensor or signal transduction systems through the conjugation of a conformationally switchable extramembrane peptide/protein segment to a suitable transmembrane peptide segment.
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Affiliation(s)
- Shiroh Futaki
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Daisuke Noshiro
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Tatsuto Kiwada
- Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Koji Asami
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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16
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Rahaman A, Lazaridis T. A thermodynamic approach to alamethicin pore formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:98-105. [PMID: 24071593 DOI: 10.1016/j.bbamem.2013.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/10/2013] [Accepted: 09/17/2013] [Indexed: 12/15/2022]
Abstract
The structure and energetics of alamethicin Rf30 monomer to nonamer in cylindrical pores of 5 to 11Å radius are investigated using molecular dynamics simulations in an implicit membrane model that includes the free energy cost of acyl chain hydrophobic area exposure. Stable, low energy pores are obtained for certain combinations of radius and oligomeric number. The trimer and the tetramer formed 6Å pores that appear closed while the larger oligomers formed open pores at their optimal radius. The hexamer in an 8Å pore and the octamer in an 11Å pore give the lowest effective energy per monomer. However, all oligomers beyond the pentamer have comparable energies, consistent with the observation of multiple conductance levels. The results are consistent with the widely accepted "barrel-stave" model. The N terminal portion of the molecule exhibits smaller tilt with respect to the membrane normal than the C terminal portion, resulting in a pore shape that is a hybrid between a funnel and an hourglass. Transmembrane voltage has little effect on the structure of the oligomers but enhances or decreases their stability depending on its orientation. Antiparallel bundles are lower in energy than the commonly accepted parallel ones and could be present under certain experimental conditions. Dry aggregates (without an aqueous pore) have lower average effective energy than the corresponding aggregates in a pore, suggesting that alamethicin pores may be excited states that are stabilized in part by voltage and in part by the ion flow itself.
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Affiliation(s)
- Asif Rahaman
- Department of Chemistry, City College of New York, 160 Convent Avenue, New York, NY 10031, USA
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17
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Noshiro D, Sonomura K, Yu HH, Imanishi M, Asami K, Futaki S. Construction of a Ca(2+)-gated artificial channel by fusing alamethicin with a calmodulin-derived extramembrane segment. Bioconjug Chem 2013; 24:188-95. [PMID: 23272973 DOI: 10.1021/bc300468x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Using native chemical ligation, we constructed a Ca(2+)-gated fusion channel protein consisting of alamethicin and the C-terminal domain of calmodulin. At pH 5.4 and in the absence of Ca(2+), this fusion protein yielded a burst-like channel current with no discrete channel conductance levels. However, Ca(2+) significantly lengthened the specific channel open state and increased the mean channel current, while Mg(2+) produced no significant changes in the channel current. On the basis of 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescent measurement, Ca(2+)-stimulated gating may be related to an increased surface hydrophobicity of the extramembrane segment of the fusion protein.
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Affiliation(s)
- Daisuke Noshiro
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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18
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Noshiro D, Asami K, Futaki S. Control of leakage activities of alamethicin analogs by metals: Side chain-dependent adverse gating response to Zn2+. Bioorg Med Chem 2012; 20:6870-6. [DOI: 10.1016/j.bmc.2012.09.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 09/16/2012] [Accepted: 09/17/2012] [Indexed: 10/27/2022]
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19
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Hjørringgaard CU, Vad BS, Matchkov VV, Nielsen SB, Vosegaard T, Nielsen NC, Otzen DE, Skrydstrup T. Cyclodextrin-scaffolded alamethicin with remarkably efficient membrane permeabilizing properties and membrane current conductance. J Phys Chem B 2012; 116:7652-9. [PMID: 22676384 DOI: 10.1021/jp2098679] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bacterial resistance to classical antibiotics is a serious medical problem, which continues to grow. Small antimicrobial peptides represent a potential solution and are increasingly being developed as novel therapeutic agents. Many of these peptides owe their antibacterial activity to the formation of trans-membrane ion-channels resulting in cell lysis. However, to further develop the field of peptide antibiotics, a thorough understanding of their mechanism of action is needed. Alamethicin belongs to a class of peptides called peptaibols and represents one of these antimicrobial peptides. To examine the dynamics of assembly and to facilitate a thorough structural evaluation of the alamethicin ion-channels, we have applied click chemistry for the synthesis of templated alamethicin multimers covalently attached to cyclodextrin-scaffolds. Using oriented circular dichroism, calcein release assays, and single-channel current measurements, the α-helices of the templated multimers were demonstrated to insert into lipid bilayers forming highly efficient and remarkably stable ion-channels.
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Affiliation(s)
- Claudia U Hjørringgaard
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
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20
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21
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Wilson MA, Wei C, Bjelkmar P, Wallace BA, Pohorille A. Molecular dynamics simulation of the antiamoebin ion channel: linking structure and conductance. Biophys J 2011; 100:2394-402. [PMID: 21575573 DOI: 10.1016/j.bpj.2011.03.054] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 03/21/2011] [Accepted: 03/24/2011] [Indexed: 11/19/2022] Open
Abstract
Molecular-dynamics simulations were carried out to ascertain which of the potential multimeric forms of the transmembrane peptaibol channel, antiamoebin, is consistent with its measured conductance. Estimates of the conductance obtained through counting ions that cross the channel and by solving the Nernst-Planck equation yield consistent results, indicating that the motion of ions inside the channel can be satisfactorily described as diffusive. The calculated conductance of octameric channels is markedly higher than the conductance measured in single channel recordings, whereas the tetramer appears to be nonconducting. The conductance of the hexamer was estimated to be 115 ± 34 pS and 74 ± 20 pS, at 150 mV and 75 mV, respectively, in satisfactory agreement with the value of 90 pS measured at 75 mV. On this basis, we propose that the antiamoebin channel consists of six monomers. Its pore is large enough to accommodate K⁺ and Cl⁻ with their first solvation shells intact. The free energy barrier encountered by K⁺ is only 2.2 kcal/mol whereas Cl⁻ encounters a substantially higher barrier of nearly 5 kcal/mol. This difference makes the channel selective for cations. Ion crossing events are shown to be uncorrelated and follow Poisson statistics.
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Affiliation(s)
- Michael A Wilson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, USA
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22
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Noshiro D, Asami K, Futaki S. Metal-assisted channel stabilization: disposition of a single histidine on the N-terminus of alamethicin yields channels with extraordinarily long lifetimes. Biophys J 2010; 98:1801-8. [PMID: 20441743 DOI: 10.1016/j.bpj.2010.01.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 11/08/2009] [Accepted: 01/04/2010] [Indexed: 10/19/2022] Open
Abstract
Alamethicin, a member of the peptaibol family of antibiotics, is a typical channel-forming peptide with a helical structure. The self-assembly of the peptide in the membranes yields voltage-dependent channels. In this study, three alamethicin analogs possessing a charged residue (His, Lys, or Glu) on their N-termini were designed with the expectation of stabilizing the transmembrane structure. A slight elongation of channel lifetime was observed for the Lys and Glu analogs. On the other hand, extensive stabilization of certain channel open states was observed for the His analog. This stabilization was predominantly observed in the presence of metal ions such as Zn(2+), suggesting that metal coordination with His facilitates the formation of a supramolecular assembly in the membranes. Channel stability was greatly diminished by acetylation of the N-terminal amino group, indicating that the N-terminal amino group also plays an important role in metal coordination.
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Affiliation(s)
- Daisuke Noshiro
- Institute for Chemical Research, Kyoto University, Kyoto, Japan
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23
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Ishiyama A, Otoguro K, Iwatsuki M, Iwatsuki M, Namatame M, Nishihara A, Nonaka K, Kinoshita Y, Takahashi Y, Masuma R, Shiomi K, Yamada H, Omura S. In vitro and in vivo antitrypanosomal activities of three peptide antibiotics: leucinostatin A and B, alamethicin I and tsushimycin. J Antibiot (Tokyo) 2009; 62:303-8. [PMID: 19407848 DOI: 10.1038/ja.2009.32] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the course of our screening for antitrypanosomal compounds from soil microorganisms, as well as from the antibiotics library of the Kitasato Institute for Life Sciences, we found three peptide antibiotics, leucinostatin (A and B), alamethicin I and tsushimycin, which exhibited potent or moderate antitrypanosomal activity. We report here the in vitro and in vivo antitrypanosomal properties and cytotoxicities of leucinostatin A and B, alamethicin I and tsushimycin compared with suramin. We also discuss their possible mode of action. This is the first report of in vitro and in vivo trypanocidal activity of leucinostatin A and B, alamethicin I and tsushimycin.
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Affiliation(s)
- Aki Ishiyama
- Research Center for Tropical Diseases, Center for Basic Research, Kitasato Institute for Life Sciences and Graduate School of Infectious Control Sciences, Kitasato University, Tokyo, Japan
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Broniatowski M, Vila-Romeu N, Dynarowicz-Łatka P. Two-Dimensional Miscibility Studies of Alamethicin and Selected Film-Forming Molecules. J Phys Chem B 2008; 112:7762-70. [DOI: 10.1021/jp800234k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Marcin Broniatowski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland, and Faculty of Sciences, Department of Physical Chemistry, University of Vigo, Campus Ourense, As Lagoas s/n, 32004 Ourense, Spain
| | - Nuria Vila-Romeu
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland, and Faculty of Sciences, Department of Physical Chemistry, University of Vigo, Campus Ourense, As Lagoas s/n, 32004 Ourense, Spain
| | - Patrycja Dynarowicz-Łatka
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland, and Faculty of Sciences, Department of Physical Chemistry, University of Vigo, Campus Ourense, As Lagoas s/n, 32004 Ourense, Spain
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