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Kim YH, Hang L, Cifelli JL, Sept D, Mayer M, Yang J. Frequency-Based Analysis of Gramicidin A Nanopores Enabling Detection of Small Molecules with Picomolar Sensitivity. Anal Chem 2018; 90:1635-1642. [DOI: 10.1021/acs.analchem.7b02961] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | | | | | - David Sept
- Department
of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2110, United States
| | - Michael Mayer
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
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2
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Xin P, Tan S, Wang Y, Sun Y, Wang Y, Xu Y, Chen CP. Functionalized hydrazide macrocycle ion channels showing pH-sensitive ion selectivities. Chem Commun (Camb) 2017; 53:625-628. [DOI: 10.1039/c6cc08943g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The protonation and deprotonation of multiple amines and carboxyls in channels change the charge distribution, which leads to pH-sensitive ion selectivity.
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Affiliation(s)
- Pengyang Xin
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Si Tan
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Yaodong Wang
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Yonghui Sun
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Yan Wang
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Yuqing Xu
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
| | - Chang-Po Chen
- School of Chemistry and Chemical Engineering
- Henan Normal University
- Xinxiang
- China
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3
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Gurnev PA, Nestorovich EM. Channel-forming bacterial toxins in biosensing and macromolecule delivery. Toxins (Basel) 2014; 6:2483-540. [PMID: 25153255 PMCID: PMC4147595 DOI: 10.3390/toxins6082483] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/08/2014] [Accepted: 08/08/2014] [Indexed: 12/19/2022] Open
Abstract
To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on "Intracellular Traffic and Transport of Bacterial Protein Toxins", reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their "second life" in a variety of developing medical and technological applications.
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Affiliation(s)
- Philip A Gurnev
- Physics Department, University of Massachusetts, Amherst, MA 01003, USA.
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4
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Design of peptide-membrane interactions to modulate single-file water transport through modified gramicidin channels. Biophys J 2012; 103:1698-705. [PMID: 23083713 DOI: 10.1016/j.bpj.2012.08.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 08/22/2012] [Accepted: 08/23/2012] [Indexed: 11/22/2022] Open
Abstract
Water permeability through single-file channels is affected by intrinsic factors such as their size and polarity and by external determinants like their lipid environment in the membrane. Previous computational studies revealed that the obstruction of the channel by lipid headgroups can be long-lived, in the range of nanoseconds, and that pore-length-matching membrane mimetics could speed up water permeability. To test the hypothesis of lipid-channel interactions modulating channel permeability, we designed different gramicidin A derivatives with attached acyl chains. By combining extensive molecular-dynamics simulations and single-channel water permeation measurements, we show that by tuning lipid-channel interactions, these modifications reduce the presence of lipid headgroups in the pore, which leads to a clear and selective increase in their water permeability.
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5
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Rokitskaya TI, Sorochkina AI, Kovalchuk SI, Egorova NS, Kotova EA, Sychev SV, Antonenko YN. The pH-dependent induction of lipid membrane ionic permeability by N-terminally lysine-substituted analogs of gramicidin A. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2011; 41:129-38. [DOI: 10.1007/s00249-011-0764-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 09/30/2011] [Accepted: 10/11/2011] [Indexed: 11/29/2022]
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6
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Majd S, Yusko EC, Billeh YN, Macrae MX, Yang J, Mayer M. Applications of biological pores in nanomedicine, sensing, and nanoelectronics. Curr Opin Biotechnol 2010; 21:439-76. [PMID: 20561776 PMCID: PMC3121537 DOI: 10.1016/j.copbio.2010.05.002] [Citation(s) in RCA: 264] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 05/03/2010] [Accepted: 05/06/2010] [Indexed: 12/29/2022]
Abstract
Biological protein pores and pore-forming peptides can generate a pathway for the flux of ions and other charged or polar molecules across cellular membranes. In nature, these nanopores have diverse and essential functions that range from maintaining cell homeostasis and participating in cell signaling to activating or killing cells. The combination of the nanoscale dimensions and sophisticated - often regulated - functionality of these biological pores make them particularly attractive for the growing field of nanobiotechnology. Applications range from single-molecule sensing to drug delivery and targeted killing of malignant cells. Potential future applications may include the use of nanopores for single strand DNA sequencing and for generating bio-inspired, and possibly, biocompatible visual detection systems and batteries. This article reviews the current state of applications of pore-forming peptides and proteins in nanomedicine, sensing, and nanoelectronics.
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Affiliation(s)
- Sheereen Majd
- Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109-2110, USA
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7
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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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8
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Macrae MX, Blake S, Jiang X, Capone R, Estes DJ, Mayer M, Yang J. A semi-synthetic ion channel platform for detection of phosphatase and protease activity. ACS NANO 2009; 3:3567-80. [PMID: 19860382 PMCID: PMC2805247 DOI: 10.1021/nn901231h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Sensitive methods to probe the activity of enzymes are important for clinical assays and for elucidating the role of these proteins in complex biochemical networks. This paper describes a semi-synthetic ion channel platform for detecting the activity of two different classes of enzymes with high sensitivity. In the first case, this method uses single ion channel conductance measurements to follow the enzyme-catalyzed hydrolysis of a phosphate group attached to the C-terminus of gramicidin A (gA, an ion channel-forming peptide) in the presence of alkaline phosphatase (AP). Enzymatic hydrolysis of this phosphate group removes negative charges from the entrance of the gA pore, resulting in a product with measurably reduced single ion channel conductance compared to the original gA-phosphate substrate. This technique employs a standard, commercial bilayer setup and takes advantage of the catalytic turnover of enzymes and the amplification characteristics of ion flux through individual gA pores to detect picomolar concentrations of active AP in solution. Furthermore, this technique makes it possible to study the kinetics of an enzyme and provides an estimate for the observed rate constant (k(cat)) and the Michaelis constant (K(M)) by following the conversion of the gA-phosphate substrate to product over time in the presence of different concentrations of AP. In the second case, modification of gA with a substrate for proteolytic cleavage by anthrax lethal factor (LF) afforded a sensitive method for detection of LF activity, illustrating the utility of ion channel-based sensing for detection of a potential biowarfare agent. This ion channel-based platform represents a powerful, novel approach to monitor the activity of femtomoles to picomoles of two different classes of enzymes in solution. Furthermore, this platform has the potential for realizing miniaturized, cost-effective bioanalytical assays that complement currently established assays.
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Affiliation(s)
- Michael X. Macrae
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA 92093-0358
| | - Steven Blake
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA 92093-0358
| | - Xiayun Jiang
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109-2110
| | - Ricardo Capone
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109-2110
| | - Daniel J. Estes
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109-2110
| | - Michael Mayer
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, MI 48109-2110
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA 92093-0358
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9
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Hansen JS, Perry M, Vogel J, Groth JS, Vissing T, Larsen MS, Geschke O, Emneús J, Bohr H, Nielsen CH. Large scale biomimetic membrane arrays. Anal Bioanal Chem 2009; 395:719-27. [DOI: 10.1007/s00216-009-3010-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 07/22/2009] [Accepted: 07/23/2009] [Indexed: 10/20/2022]
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10
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Portella G, de Groot BL. Determinants of water permeability through nanoscopic hydrophilic channels. Biophys J 2009; 96:925-38. [PMID: 19186131 DOI: 10.1016/j.bpj.2008.09.059] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Accepted: 09/22/2008] [Indexed: 11/17/2022] Open
Abstract
Naturally occurring pores show a variety of polarities and sizes that are presumably directly linked to their biological function. Many biological channels are selective toward permeants similar or smaller in size than water molecules, and therefore their pores operate in the regime of single-file water pores. Intrinsic factors affecting water permeability through such pores include the channel-membrane match, the structural stability of the channel, the channel geometry and channel-water affinity. We present an extensive molecular dynamics study on the role of the channel geometry and polarity on the water osmotic and diffusive permeability coefficients. We show that the polarity of the naturally occurring peptidic channels is close to optimal for water permeation, and that the water mobility for a wide range of channel polarities is essentially length independent. By systematically varying the geometry and polarity of model hydrophilic pores, based on the fold of gramicidin A, the water density, occupancy, and permeability are studied. Our focus is on the characterization of the transition between different permeation regimes in terms of the structure of water in the pores, the average pore occupancy and the dynamics of the permeating water molecules. We show that a general relationship between osmotic and diffusive water permeability coefficients in the single-file regime accounts for the time averaged pore occupancy, and that the dynamics of the permeating water molecules through narrow non single file channels effectively behaves like independent single-file columns.
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Affiliation(s)
- Guillem Portella
- Computational Biomolecular Dynamics Group, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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11
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Blake S, Capone R, Mayer M, Yang J. Chemically Reactive Derivatives of Gramicidin A for Developing Ion Channel-Based Nanoprobes. Bioconjug Chem 2008; 19:1614-24. [DOI: 10.1021/bc800180z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven Blake
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, and Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109
| | - Ricardo Capone
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, and Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109
| | - Michael Mayer
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, and Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, and Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109
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12
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Mayer M, Semetey V, Gitlin I, Yang J, Whitesides GM. Using ion channel-forming peptides to quantify protein-ligand interactions. J Am Chem Soc 2008; 130:1453-65. [PMID: 18179217 DOI: 10.1021/ja077555f] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper proposes a method for sensing affinity interactions by triggering disruption of self-assembly of ion channel-forming peptides in planar lipid bilayers. It shows that the binding of a derivative of alamethicin carrying a covalently attached sulfonamide ligand to carbonic anhydrase II (CA II) resulted in the inhibition of ion channel conductance through the bilayer. We propose that the binding of the bulky CA II protein (MW approximately 30 kD) to the ion channel-forming peptides (MW approximately 2.5 kD) either reduced the tendency of these peptides to self-assemble into a pore or extracted them from the bilayer altogether. In both outcomes, the interactions between the protein and the ligand lead to a disruption of self-assembled pores. Addition of a competitive inhibitor, 4-carboxybenzenesulfonamide, to the solution released CA II from the alamethicin-sulfonamide conjugate and restored the current flow across the bilayer by allowing reassembly of the ion channels in the bilayer. Time-averaged recordings of the current over discrete time intervals made it possible to quantify this monovalent ligand binding interaction. This method gave a dissociation constant of approximately 2 microM for the binding of CA II to alamethicin-sulfonamide in the bilayer recording chamber: this value is consistent with a value obtained independently with CA II and a related sulfonamide derivative by isothermal titration calorimetry.
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Affiliation(s)
- Michael Mayer
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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13
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Madhavan N, Gin MS. Increasing pH Causes Faster Anion- and Cation-Transport Rates through a Synthetic Ion Channel. Chembiochem 2007; 8:1834-40. [PMID: 17868157 DOI: 10.1002/cbic.200700321] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ion-channel mimics are able to transmit electrical signals across phospholipid membranes, and can be envisioned as nanoswitches for molecular electronics. Here, we reported the use of pH to alter ion-transport rates through a synthetic aminocyclodextrin ion channel. Both cation- and anion-transport rates were found to increase with an increase in pH due to the unique electrostatics of the multiple ammonium groups that line the channel pore. Such pH regulation of ion transport rates is unique and can be exploited for sensing applications.
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Affiliation(s)
- Nandita Madhavan
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
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14
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Affiliation(s)
- Rachel S. Hector
- a Department of Chemistry , University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, IL 61801, USA
| | - Mary S. Gin
- a Department of Chemistry , University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, IL 61801, USA
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15
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Antonenko YN, Stoilova TB, Kovalchuk SI, Egorova NS, Pashkovskaya AA, Sobko AA, Kotova EA, Surovoy AY. Redox-regulated ion channel activity of a cysteine-containing gramicidin A analogue. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:493-8. [PMID: 16624254 DOI: 10.1016/j.bbamem.2006.02.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 01/16/2006] [Accepted: 02/20/2006] [Indexed: 11/29/2022]
Abstract
According to recent data, gramicidin A analogues having positively charged amino acid sequences at the C-termini exhibit two types of channel activity in lipid membranes: classical cation-selective channels and large unselective pores. The induction of unselective pores was shown here to strongly depend on the redox state of the membrane-bathing solution, if the gramicidin analogue contained a cysteine residue in the sequence GSGPKKKRKVC attached to the C-terminus. In particular, the addition of H2O2 led to an increase in the transmembrane current and the loss of cationic selectivity on planar bilayer lipid membranes and an increase in the carboxyfluorescein leakage of liposomes. The effect was observed at high concentration of the peptide while was absent at the single-channel level. It was concluded that oxidation led to possible formation of dimers of the peptide, which promoted the formation of large unselective pores.
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Affiliation(s)
- Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.
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16
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Blake S, Mayer T, Mayer M, Yang J. Monitoring Chemical Reactions by Using Ion-Channel-Forming Peptides. Chembiochem 2006; 7:433-5. [PMID: 16444770 DOI: 10.1002/cbic.200500532] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Steven Blake
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA 92093-0358, USA
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17
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Chen WH, Nishikawa M, Tan SD, Yamamura M, Satake A, Kobuke Y. Tetracyanoresorcin[4]arene ion channel shows pH dependent conductivity change. Chem Commun (Camb) 2004:872-3. [PMID: 15045106 DOI: 10.1039/b312952g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pH sensitive artificial ion channel, tetracyanoresorcin[4]arene, whose pK(a1) to pK(a3) are around pH 7, was synthesized. Conductivities for potassium ion were increased by the progress of dissociation at the channel mouth.
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Affiliation(s)
- Wen-Hua Chen
- CREST, Japan Science and Technology Corporation (JST), Kawaguchi Center Building 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012, Japan
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18
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Antonenko YN, Borisenko V, Melik-Nubarov NS, Kotova EA, Woolley GA. Polyanions decelerate the kinetics of positively charged gramicidin channels as shown by sensitized photoinactivation. Biophys J 2002; 82:1308-18. [PMID: 11867447 PMCID: PMC1301933 DOI: 10.1016/s0006-3495(02)75486-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The effects of different anionic polymers on the kinetic properties of ionic channels formed by neutral gramicidin A (gA) and its positively charged analogs gramicidin-tris(2-aminoethyl)amine (gram-TAEA) and gramicidin-ethylenediamine (gram-EDA) in a bilayer lipid membrane were studied using a method of sensitized photoinactivation. The addition of Konig's polyanion caused substantial deceleration of the photoinactivation kinetics of gram-TAEA channels, which expose three positive charges to the aqueous phase at both sides of the membrane. In contrast, channels formed of gram-EDA, which exposes one positive charge, and neutral gA channels were insensitive to Konig's polyanion. The effect strongly depended on the nature of the polyanion added, namely: DNA, RNA, polyacrylic acid, and polyglutamic acid were inactive, whereas modified polyacrylic acid induced deceleration of the channel kinetics at high concentrations. In addition, DNA was able to prevent the action of Konig's polyanion. In single-channel experiments, the addition of Konig's polyanion resulted in the appearance of long-lived gram-TAEA channels. The deceleration of the gram-TAEA channel kinetics was ascribed to electrostatic interaction of the polyanion with gram-TAEA that reduces the mobility of gram-TAEA monomers and dimers in the membrane via clustering of channels.
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Affiliation(s)
- Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, School of Chemistry, Moscow State University, Moscow 119899 Russia.
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