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Emigh Cortez AM, DeMarco KR, Furutani K, Bekker S, Sack JT, Wulff H, Clancy CE, Vorobyov I, Yarov-Yarovoy V. Structural modeling of hERG channel-drug interactions using Rosetta. Front Pharmacol 2023; 14:1244166. [PMID: 38035013 PMCID: PMC10682396 DOI: 10.3389/fphar.2023.1244166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
The human ether-a-go-go-related gene (hERG) not only encodes a potassium-selective voltage-gated ion channel essential for normal electrical activity in the heart but is also a major drug anti-target. Genetic hERG mutations and blockage of the channel pore by drugs can cause long QT syndrome, which predisposes individuals to potentially deadly arrhythmias. However, not all hERG-blocking drugs are proarrhythmic, and their differential affinities to discrete channel conformational states have been suggested to contribute to arrhythmogenicity. We used Rosetta electron density refinement and homology modeling to build structural models of open-state hERG channel wild-type and mutant variants (Y652A, F656A, and Y652A/F656 A) and a closed-state wild-type channel based on cryo-electron microscopy structures of hERG and EAG1 channels. These models were used as protein targets for molecular docking of charged and neutral forms of amiodarone, nifekalant, dofetilide, d/l-sotalol, flecainide, and moxifloxacin. We selected these drugs based on their different arrhythmogenic potentials and abilities to facilitate hERG current. Our docking studies and clustering provided atomistic structural insights into state-dependent drug-channel interactions that play a key role in differentiating safe and harmful hERG blockers and can explain hERG channel facilitation through drug interactions with its open-state hydrophobic pockets.
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Affiliation(s)
- Aiyana M. Emigh Cortez
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kevin R. DeMarco
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kazuharu Furutani
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, Tokushima Bunri University, Tokushima, Japan
| | - Slava Bekker
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- American River College, Sacramento, CA, United States
| | - Jon T. Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Colleen E. Clancy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
- Center for Precision Medicine and Data Sciences, University of California, Davis, Davis, CA, United States
| | - Igor Vorobyov
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
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2
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Ma T, Sato M, Komiya M, Feng X, Tadaki D, Hirano-Iwata A. Advances in Artificial Bilayer Lipid Membranes as a Novel Biosensing Platform: From Drug-screening to Self-assembled Devices. CHEM LETT 2021. [DOI: 10.1246/cl.200764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Teng Ma
- Advanced Institute for Materials Research (WPI-AIMR), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Madoka Sato
- Research Institute of Electrical Communication (RIEC), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Maki Komiya
- Research Institute of Electrical Communication (RIEC), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Xingyao Feng
- Research Institute of Electrical Communication (RIEC), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Daisuke Tadaki
- Research Institute of Electrical Communication (RIEC), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Ayumi Hirano-Iwata
- Advanced Institute for Materials Research (WPI-AIMR), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
- Research Institute of Electrical Communication (RIEC), 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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3
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Parallel Recordings of Transmembrane hERG Channel Currents Based on Solvent-Free Lipid Bilayer Microarray. MICROMACHINES 2021; 12:mi12010098. [PMID: 33478052 PMCID: PMC7835820 DOI: 10.3390/mi12010098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/23/2022]
Abstract
The reconstitution of ion-channel proteins in artificially formed bilayer lipid membranes (BLMs) forms a well-defined system for the functional analysis of ion channels and screening of the effects of drugs that act on these proteins. To improve the efficiency of the BLM reconstitution system, we report on a microarray of stable solvent-free BLMs formed in microfabricated silicon (Si) chips, where micro-apertures with well-defined nano- and micro-tapered edges were fabricated. Sixteen micro-wells were manufactured in a chamber made of Teflon®, and the Si chips were individually embedded in the respective wells as a recording site. Typically, 11 to 16 BLMs were simultaneously formed with an average BLM number of 13.1, which corresponded to a formation probability of 82%. Parallel recordings of ion-channel activities from multiple BLMs were successfully demonstrated using the human ether-a-go-go-related gene (hERG) potassium channel, of which the relation to arrhythmic side effects following drug treatment is well recognized.
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Yang PC, DeMarco KR, Aghasafari P, Jeng MT, Dawson JRD, Bekker S, Noskov SY, Yarov-Yarovoy V, Vorobyov I, Clancy CE. A Computational Pipeline to Predict Cardiotoxicity: From the Atom to the Rhythm. Circ Res 2020; 126:947-964. [PMID: 32091972 DOI: 10.1161/circresaha.119.316404] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
RATIONALE Drug-induced proarrhythmia is so tightly associated with prolongation of the QT interval that QT prolongation is an accepted surrogate marker for arrhythmia. But QT interval is too sensitive a marker and not selective, resulting in many useful drugs eliminated in drug discovery. OBJECTIVE To predict the impact of a drug from the drug chemistry on the cardiac rhythm. METHODS AND RESULTS In a new linkage, we connected atomistic scale information to protein, cell, and tissue scales by predicting drug-binding affinities and rates from simulation of ion channel and drug structure interactions and then used these values to model drug effects on the hERG channel. Model components were integrated into predictive models at the cell and tissue scales to expose fundamental arrhythmia vulnerability mechanisms and complex interactions underlying emergent behaviors. Human clinical data were used for model framework validation and showed excellent agreement, demonstrating feasibility of a new approach for cardiotoxicity prediction. CONCLUSIONS We present a multiscale model framework to predict electrotoxicity in the heart from the atom to the rhythm. Novel mechanistic insights emerged at all scales of the system, from the specific nature of proarrhythmic drug interaction with the hERG channel, to the fundamental cellular and tissue-level arrhythmia mechanisms. Applications of machine learning indicate necessary and sufficient parameters that predict arrhythmia vulnerability. We expect that the model framework may be expanded to make an impact in drug discovery, drug safety screening for a variety of compounds and targets, and in a variety of regulatory processes.
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Affiliation(s)
- Pei-Chi Yang
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis
| | - Kevin R DeMarco
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis
| | - Parya Aghasafari
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis
| | - Mao-Tsuen Jeng
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis
| | - John R D Dawson
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis.,Biophysics Graduate Group (J.R.D.D.), University of California Davis
| | - Slava Bekker
- Department of Science and Engineering, American River College, Sacramento, CA (S.B.)
| | - Sergei Y Noskov
- Faculty of Science, Centre for Molecular Simulations and Department of Biological Sciences, University of Calgary, Alberta, Canada (S.Y.N.)
| | - Vladimir Yarov-Yarovoy
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis
| | - Igor Vorobyov
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis.,Department of Pharmacology (I.V., C.E.C.), University of California Davis
| | - Colleen E Clancy
- From the Department of Physiology and Membrane Biology (P.-C.Y., K.R.D., P.A., M.-T.J., J.R.D.D., V.Y.-Y., I.V., C.E.C.), University of California Davis.,Department of Pharmacology (I.V., C.E.C.), University of California Davis
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5
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Selectivity filter modalities and rapid inactivation of the hERG1 channel. Proc Natl Acad Sci U S A 2020; 117:2795-2804. [PMID: 31980532 DOI: 10.1073/pnas.1909196117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The human ether-á-go-go-related gene (hERG1) channel conducts small outward K+ currents that are critical for cardiomyocyte membrane repolarization. The gain-of-function mutation N629D at the outer mouth of the selectivity filter (SF) disrupts inactivation and K+-selective transport in hERG1, leading to arrhythmogenic phenotypes associated with long-QT syndrome. Here, we combined computational electrophysiology with Markov state model analysis to investigate how SF-level gating modalities control selective cation transport in wild-type (WT) and mutant (N629D) hERG1 variants. Starting from the recently reported cryogenic electron microscopy (cryo-EM) open-state channel structure, multiple microseconds-long molecular-dynamics (MD) trajectories were generated using different cation configurations at the filter, voltages, electrolyte concentrations, and force-field parameters. Most of the K+ permeation events observed in hERG1-WT simulations occurred at microsecond timescales, influenced by the spontaneous dehydration/rehydration dynamics at the filter. The SF region displayed conductive, constricted, occluded, and dilated states, in qualitative agreement with the well-documented flickering conductance of hERG1. In line with mutagenesis studies, these gating modalities resulted from dynamic interaction networks involving residues from the SF, outer-mouth vestibule, P-helices, and S5-P segments. We found that N629D mutation significantly stabilizes the SF in a state that is permeable to both K+ and Na+, which is reminiscent of the SF in the nonselective bacterial NaK channel. Increasing the external K+ concentration induced "WT-like" SF dynamics in N629D, in qualitative agreement with the recovery of flickering currents in experiments. Overall, our findings provide an understanding of the molecular mechanisms controlling selective transport in K+ channels with a nonconventional SF sequence.
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6
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Komiya M, Kato M, Tadaki D, Ma T, Yamamoto H, Tero R, Tozawa Y, Niwano M, Hirano‐Iwata A. Advances in Artificial Cell Membrane Systems as a Platform for Reconstituting Ion Channels. CHEM REC 2020; 20:730-742. [DOI: 10.1002/tcr.201900094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/24/2019] [Accepted: 12/27/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Maki Komiya
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
| | - Miki Kato
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
| | - Daisuke Tadaki
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
| | - Teng Ma
- Advanced Institute for Materials ResearchTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
| | - Hideaki Yamamoto
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
| | - Ryugo Tero
- Department of Applied Chemistry and Life ScienceToyohashi University of Technology 1-1 Hibarigaoka, Tempaku-cho, Toyohashi Aichi 441-8580 Japan
| | - Yuzuru Tozawa
- Graduate School of Science and EngineeringSaitama University 255 Shimo-Okubo, Sakura-ku, Saitama-shi Saitama 338-8570 Japan
| | - Michio Niwano
- Kansei Fukushi Research InstituteTohoku Fukushi University 6-149-1 Kunimi-ga-oka, Aoba-ku, Sendai-shi Miyagi 989-3201 Japan
| | - Ayumi Hirano‐Iwata
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
- Advanced Institute for Materials ResearchTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
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7
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KOMIYA M, MA T, TADAKI D, HIRANO-IWATA A. Development of an Analytical System for Ion Channel Proteins Based on Artificial Bilayer Lipid Membranes —Screening of Drug Components that Haveing Side Effects on hERG Channels for Personalized Medicine—. BUNSEKI KAGAKU 2018. [DOI: 10.2116/bunsekikagaku.67.749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Maki KOMIYA
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University
| | - Teng MA
- Advanced Institute for Materials Research, Tohoku University
| | - Daisuke TADAKI
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University
| | - Ayumi HIRANO-IWATA
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University
- Advanced Institute for Materials Research, Tohoku University
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8
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Tadaki D, Yamaura D, Araki S, Yoshida M, Arata K, Ohori T, Ishibashi KI, Kato M, Ma T, Miyata R, Tozawa Y, Yamamoto H, Niwano M, Hirano-Iwata A. Mechanically stable solvent-free lipid bilayers in nano- and micro-tapered apertures for reconstitution of cell-free synthesized hERG channels. Sci Rep 2017; 7:17736. [PMID: 29255199 PMCID: PMC5735097 DOI: 10.1038/s41598-017-17905-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/01/2017] [Indexed: 01/08/2023] Open
Abstract
The self-assembled bilayer lipid membrane (BLM) is the basic component of the cell membrane. The reconstitution of ion channel proteins in artificially formed BLMs represents a well-defined system for the functional analysis of ion channels and screening the effects of drugs that act on them. However, because BLMs are unstable, this limits the experimental throughput of BLM reconstitution systems. Here we report on the formation of mechanically stable solvent-free BLMs in microfabricated apertures with defined nano- and micro-tapered edge structures. The role of such nano- and micro-tapered structures on the stability of the BLMs was also investigated. Finally, this BLM system was combined with a cell-free synthesized human ether-a-go-go-related gene channel, a cardiac potassium channel whose relation to arrhythmic side effects following drug treatment is well recognized. Such stable BLMs as these, when combined with a cell-free system, represent a potential platform for screening the effects of drugs that act on various ion-channel genotypes.
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Affiliation(s)
- Daisuke Tadaki
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Daichi Yamaura
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Shun Araki
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Miyu Yoshida
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Kohei Arata
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Takeshi Ohori
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Ken-Ichi Ishibashi
- Hang-Ichi Corporation, 1-7-315 Honcho, Naka-ku, Yokohama, Kanagawa, 231-0005, Japan
| | - Miki Kato
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Teng Ma
- Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Ryusuke Miyata
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Yuzuru Tozawa
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, 338-8570, Japan
| | - Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Michio Niwano
- Kansei Fukushi Research Institute, Tohoku Fukushi University, 6-149-1 Kunimi-ga-oka, Aoba-ku, Sendai, Miyagi, 989-3201, Japan
| | - Ayumi Hirano-Iwata
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan. .,Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
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9
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Hirano-Iwata A, Ishinari Y, Yoshida M, Araki S, Tadaki D, Miyata R, Ishibashi K, Yamamoto H, Kimura Y, Niwano M. Reconstitution of Human Ion Channels into Solvent-free Lipid Bilayers Enhanced by Centrifugal Forces. Biophys J 2017; 110:2207-15. [PMID: 27224486 DOI: 10.1016/j.bpj.2016.04.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 04/11/2016] [Accepted: 04/11/2016] [Indexed: 12/26/2022] Open
Abstract
Artificially formed bilayer lipid membranes (BLMs) provide well-defined systems for functional analyses of various membrane proteins, including ion channels. However, difficulties associated with the integration of membrane proteins into BLMs limit the experimental efficiency and usefulness of such BLM reconstitution systems. Here, we report on the use of centrifugation to more efficiently reconstitute human ion channels in solvent-free BLMs. The method improves the probability of membrane fusion. Membrane vesicles containing the human ether-a-go-go-related gene (hERG) channel, the human cardiac sodium channel (Nav1.5), and the human GABAA receptor (GABAAR) channel were formed, and the functional reconstitution of the channels into BLMs via vesicle fusion was investigated. Ion channel currents were recorded in 67% of the BLMs that were centrifuged with membrane vesicles under appropriate centrifugal conditions (14-55 × g). The characteristic channel properties were retained for hERG, Nav1.5, and GABAAR channels after centrifugal incorporation into the BLMs. A comparison of the centrifugal force with reported values for the fusion force revealed that a centrifugal enhancement in vesicle fusion was attained, not by accelerating the fusion process but by accelerating the delivery of membrane vesicles to the surface of the BLMs, which led to an increase in the number of membrane vesicles that were available for fusion. Our method for enhancing the probability of vesicle fusion promises to dramatically increase the experimental efficiency of BLM reconstitution systems, leading to the realization of a BLM-based, high-throughput platform for functional assays of various membrane proteins.
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Affiliation(s)
- Ayumi Hirano-Iwata
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan.
| | - Yutaka Ishinari
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan
| | - Miyu Yoshida
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan
| | - Shun Araki
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan
| | - Daisuke Tadaki
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan
| | - Ryusuke Miyata
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan
| | | | - Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aoba, Sendai, Japan
| | - Yasuo Kimura
- Department of Electric and Electronic Engineering, School of Engineering, Tokyo University of Technology, Hachioji, Tokyo, Japan
| | - Michio Niwano
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan; Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai, Japan
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10
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Vijayvergiya V, Acharya S, Wilson SP, Schmidt JJ. Measurement of Ensemble TRPV1 Ion Channel Currents Using Droplet Bilayers. PLoS One 2015; 10:e0141366. [PMID: 26513481 PMCID: PMC4626236 DOI: 10.1371/journal.pone.0141366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/06/2015] [Indexed: 11/18/2022] Open
Abstract
Electrophysiological characterization of ion channels is useful for elucidation of channel function as well as quantitative assessment of pharmaceutical effects on ion channel conductance. We used droplet bilayers to measure ensemble ion channel currents from membrane preparations made from TRPV1-expressing HEK cells. Conductance measurements showed rectification, activation by acid and capsaicin, and inhibition by capsazepine, SB 452533, and JNJ 17293212. We also quantitatively measured concentration-dependent inhibition of channel conductance through determination of capsazepine IC50 in agreement with previously published studies using patch clamp. These results, combined with the reduced apparatus and material requirements of droplet bilayers, indicate that this platform could be used for study of other physiologically relevant ion channels.
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Affiliation(s)
- Viksita Vijayvergiya
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, United States of America
| | - Shiv Acharya
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, United States of America
| | - Sidney P. Wilson
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jacob J. Schmidt
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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