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Sarkar D, Mishra S, Nisal R, Majhi S, Shrivas R, Singh Y, Anusree VS, Kalia J. Site-Specific Fluorescent Labeling of the Cysteine-Rich Toxin, DkTx, for TRPV1 Ion Channel Imaging and Membrane Binding Studies. Bioconjug Chem 2022; 33:1761-1770. [PMID: 36073164 DOI: 10.1021/acs.bioconjchem.2c00355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide toxins secreted by venomous animals bind to mammalian ion channel proteins and modulate their function. The high specificity of these toxins for their target ion channels enables them to serve as powerful tools for ion channel biology. Toxins labeled with fluorescent dyes are employed for the cellular imaging of channels and also for studying toxin-channel and toxin-membrane interactions. Several of these toxins are cysteine-rich, rendering the production of properly folded fluorescently labeled toxins technically challenging. Herein, we evaluate a variety of site-specific protein bioconjugation approaches for producing fluorescently labeled double-knot toxin (DkTx), a potent TRPV1 ion channel agonist that contains an uncommonly large number of cysteines (12 out of a total of 75 amino acids present in the protein). We find that popular cysteine-mediated bioconjugation approaches are unsuccessful as the introduction of a non-native cysteine residue for thiol modification leads to the formation of misfolded toxin species. Moreover, N-terminal aldehyde-mediated bioconjugation approaches are also not suitable as the resultant labeled toxin lacks activity. In contrast to these approaches, C-terminal bioconjugation of DkTx via the sortase bioconjugation technology yields functionally active fluorescently labeled DkTx. We employ this labeled toxin for imaging rat TRPV1 heterologously expressed in Xenopus laevis oocytes, as well as for performing membrane binding studies on giant unilamellar vesicles composed of different lipid compositions. Our studies set the stage for using fluorescent DkTx as a tool for TRPV1 biology and provide an informative blueprint for labeling cysteine-rich proteins.
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Affiliation(s)
- Debayan Sarkar
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Satyajit Mishra
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Rahul Nisal
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Sumita Majhi
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Rohit Shrivas
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Yashaswi Singh
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - V S Anusree
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Jeet Kalia
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India.,Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.,Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
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Montnach J, De Waard S, Nicolas S, Burel S, Osorio N, Zoukimian C, Mantegazza M, Boukaiba R, Béroud R, Partiseti M, Delmas P, Marionneau C, De Waard M. Fluorescent- and tagged-protoxin II peptides: potent markers of the Na v 1.7 channel pain target. Br J Pharmacol 2021; 178:2632-2650. [PMID: 33742442 DOI: 10.1111/bph.15453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/26/2021] [Accepted: 02/09/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Protoxin II (ProTx II) is a high affinity gating modifier that is thought to selectively block the Nav 1.7 voltage-dependent Na+ channel, a major therapeutic target for the control of pain. We aimed at producing ProTx II analogues entitled with novel functionalities for cell distribution studies and biochemical characterization of its Nav channel targets. EXPERIMENTAL APPROACH We took advantage of the high affinity properties of the peptide, combined to its slow off rate, to design a number of new tagged analogues useful for imaging and biochemistry purposes. We used high-throughput automated patch-clamp to identify the analogues best matching the native properties of ProTx II and validated them on various Nav -expressing cells in pull-down and cell distribution studies. KEY RESULTS Two of the produced ProTx II analogues, Biot-ProTx II and ATTO488-ProTx II, best emulate the pharmacological properties of unlabelled ProTx II, whereas other analogues remain high affinity blockers of Nav 1.7. The biotinylated version of ProTx II efficiently works for the pull-down of several Nav isoforms tested in a concentration-dependent manner, whereas the fluorescent ATTO488-ProTx II specifically labels the Nav 1.7 channel over other Nav isoforms tested in various experimental conditions. CONCLUSIONS AND IMPLICATIONS The properties of these ProTx II analogues as tools for Nav channel purification and cell distribution studies pave the way for a better understanding of ProTx II channel receptors in pain and their pathophysiological implications in sensory neuronal processing. The new fluorescent ProTx II should also be useful in the design of new drug screening strategies.
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Affiliation(s)
- Jérôme Montnach
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Stephan De Waard
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Sébastien Nicolas
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Sophie Burel
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Nancy Osorio
- Laboratory of Cognitive Neuroscience, UMR 7291, CNRS, Aix-Marseille University, Marseille, France
| | | | - Massimo Mantegazza
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Rachid Boukaiba
- Sanofi R&D, Integrated Drug Discovery - High Content Biology, Vitry-sur-Seine, France
| | | | - Michel Partiseti
- Sanofi R&D, Integrated Drug Discovery - High Content Biology, Vitry-sur-Seine, France
| | - Patrick Delmas
- Laboratory of Cognitive Neuroscience, UMR 7291, CNRS, Aix-Marseille University, Marseille, France
| | - Céline Marionneau
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Michel De Waard
- LabEx "Ion Channels, Science & Therapeutics", l'institut du thorax, INSERM, CNRS, UNIV NANTES, Nantes, France.,Smartox Biotechnology, Saint-Egrève, France
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3
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Structural Pharmacology of Voltage-Gated Sodium Channels. J Mol Biol 2021; 433:166967. [PMID: 33794261 DOI: 10.1016/j.jmb.2021.166967] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium (NaV) channels initiate and propagate action potentials in excitable tissues to mediate key physiological processes including heart contraction and nervous system function. Accordingly, NaV channels are major targets for drugs, toxins and disease-causing mutations. Recent breakthroughs in cryo-electron microscopy have led to the visualization of human NaV1.1, NaV1.2, NaV1.4, NaV1.5 and NaV1.7 channel subtypes at high-resolution. These landmark studies have greatly advanced our structural understanding of channel architecture, ion selectivity, voltage-sensing, electromechanical coupling, fast inactivation, and the molecular basis underlying NaV channelopathies. NaV channel structures have also been increasingly determined in complex with toxin and small molecule modulators that target either the pore module or voltage sensor domains. These structural studies have provided new insights into the mechanisms of pharmacological action and opportunities for subtype-selective NaV channel drug design. This review will highlight the structural pharmacology of human NaV channels as well as the potential use of engineered and chimeric channels in future drug discovery efforts.
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Sodium ion channels as potential therapeutic targets for cancer metastasis. Drug Discov Today 2021; 26:1136-1147. [PMID: 33545383 DOI: 10.1016/j.drudis.2021.01.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/31/2020] [Accepted: 01/27/2021] [Indexed: 12/28/2022]
Abstract
Is it possible to develop drugs for the treatment of a specific type of metastatic cancer by targeting sodium ion channels?
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Wisedchaisri G, Tonggu L, Gamal El-Din TM, McCord E, Zheng N, Catterall WA. Structural Basis for High-Affinity Trapping of the Na V1.7 Channel in Its Resting State by Tarantula Toxin. Mol Cell 2021; 81:38-48.e4. [PMID: 33232657 PMCID: PMC8043720 DOI: 10.1016/j.molcel.2020.10.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/14/2020] [Accepted: 10/28/2020] [Indexed: 11/17/2022]
Abstract
Voltage-gated sodium channels initiate electrical signals and are frequently targeted by deadly gating-modifier neurotoxins, including tarantula toxins, which trap the voltage sensor in its resting state. The structural basis for tarantula-toxin action remains elusive because of the difficulty of capturing the functionally relevant form of the toxin-channel complex. Here, we engineered the model sodium channel NaVAb with voltage-shifting mutations and the toxin-binding site of human NaV1.7, an attractive pain target. This mutant chimera enabled us to determine the cryoelectron microscopy (cryo-EM) structure of the channel functionally arrested by tarantula toxin. Our structure reveals a high-affinity resting-state-specific toxin-channel interaction between a key lysine residue that serves as a "stinger" and penetrates a triad of carboxyl groups in the S3-S4 linker of the voltage sensor. By unveiling this high-affinity binding mode, our studies establish a high-resolution channel-docking and resting-state locking mechanism for huwentoxin-IV and provide guidance for developing future resting-state-targeted analgesic drugs.
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Affiliation(s)
| | - Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Eedann McCord
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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Employing NaChBac for cryo-EM analysis of toxin action on voltage-gated Na + channels in nanodisc. Proc Natl Acad Sci U S A 2020; 117:14187-14193. [PMID: 32513729 DOI: 10.1073/pnas.1922903117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
NaChBac, the first bacterial voltage-gated Na+ (Nav) channel to be characterized, has been the prokaryotic prototype for studying the structure-function relationship of Nav channels. Discovered nearly two decades ago, the structure of NaChBac has not been determined. Here we present the single particle electron cryomicroscopy (cryo-EM) analysis of NaChBac in both detergent micelles and nanodiscs. Under both conditions, the conformation of NaChBac is nearly identical to that of the potentially inactivated NavAb. Determining the structure of NaChBac in nanodiscs enabled us to examine gating modifier toxins (GMTs) of Nav channels in lipid bilayers. To study GMTs in mammalian Nav channels, we generated a chimera in which the extracellular fragment of the S3 and S4 segments in the second voltage-sensing domain from Nav1.7 replaced the corresponding sequence in NaChBac. Cryo-EM structures of the nanodisc-embedded chimera alone and in complex with HuwenToxin IV (HWTX-IV) were determined to 3.5 and 3.2 Å resolutions, respectively. Compared to the structure of HWTX-IV-bound human Nav1.7, which was obtained at an overall resolution of 3.2 Å, the local resolution of the toxin has been improved from ∼6 to ∼4 Å. This resolution enabled visualization of toxin docking. NaChBac can thus serve as a convenient surrogate for structural studies of the interactions between GMTs and Nav channels in a membrane environment.
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Gardill B, Huang J, Tu L, Van Petegem F, Oxenoid K, Thomson CA. Nanodisc technology facilitates identification of monoclonal antibodies targeting multi-pass membrane proteins. Sci Rep 2020; 10:1130. [PMID: 31980674 PMCID: PMC6981118 DOI: 10.1038/s41598-020-58002-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 01/08/2020] [Indexed: 12/31/2022] Open
Abstract
Multi-pass membrane proteins are important targets of biologic medicines. Given the inherent difficulties in working with membrane proteins, we sought to investigate the utility of membrane scaffold protein nanodiscs as a means of solubilizing membrane proteins to aid antibody discovery. Using a model multi-pass membrane protein, we demonstrate how incorporation of a multi-pass membrane protein into nanodiscs can be used in flow cytometry to identify antigen-specific hybridoma. The use of target protein-loaded nanodiscs to sort individual hybridoma early in the screening process can reduce the time required to identify antibodies against multi-pass membrane proteins.
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Affiliation(s)
- Bernd Gardill
- Amgen Research, Biologic Discovery, Burnaby, BC, Canada.,The University of British Columbia, Department of Biochemistry and Molecular Biology, Life Sciences Institute, Vancouver, BC, Canada.,Amgen Research, Munich, Germany
| | - Jerry Huang
- Amgen Research, Biologic Discovery, Burnaby, BC, Canada
| | - Lawrence Tu
- Amgen Research, Biologic Discovery, Burnaby, BC, Canada
| | - Filip Van Petegem
- The University of British Columbia, Department of Biochemistry and Molecular Biology, Life Sciences Institute, Vancouver, BC, Canada
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Tzakoniati F, Xu H, Li T, Garcia N, Kugel C, Payandeh J, Koth CM, Tate EW. Development of Photocrosslinking Probes Based on Huwentoxin-IV to Map the Site of Interaction on Nav1.7. Cell Chem Biol 2019; 27:306-313.e4. [PMID: 31732432 PMCID: PMC7083225 DOI: 10.1016/j.chembiol.2019.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 08/31/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023]
Abstract
Voltage-gated sodium (Nav) channels respond to changes in the membrane potential of excitable cells through the concerted action of four voltage-sensor domains (VSDs). Subtype Nav1.7 plays an important role in the propagation of signals in pain-sensing neurons and is a target for the clinical development of novel analgesics. Certain inhibitory cystine knot (ICK) peptides produced by venomous animals potently modulate Nav1.7; however, the molecular mechanisms underlying their selective binding and activity remain elusive. This study reports on the design of a library of photoprobes based on the potent spider toxin Huwentoxin-IV and the determination of the toxin binding interface on VSD2 of Nav1.7 through a photocrosslinking and tandem mass spectrometry approach. Our Huwentoxin-IV probes selectively crosslink to extracellular loop S1-S2 and helix S3 of VSD2 in a chimeric channel system. Our results provide a strategy that will enable mapping of sites of interaction of other ICK peptides on Nav channels. Development of six potent diazirine-containing photoprobes based on Huwentoxin-IV Photoprobes specifically photolabel purified bacterial-Nav1.7 VSD2 chimeric channels Proteomic mass spectrometry identifies binding site on S1-S2 loop and S3 helix Proposed model of HwTx-IV binding reveals importance of K27 and R29
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Affiliation(s)
| | - Hui Xu
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Tianbo Li
- Department of Biochemical and Cellular Pharmacology, Genentech, South San Francisco, CA 94080, USA
| | - Natalie Garcia
- Department of Protein Analytical Chemistry, Genentech, South San Francisco, CA 94080, USA
| | - Christine Kugel
- Department of Biomolecular Resources, Genentech, South San Francisco, CA 94080, USA
| | - Jian Payandeh
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Christopher M Koth
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Edward W Tate
- Department of Chemistry, Imperial College London, London W12 0BZ, UK.
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Colley CS, England E, Linley JE, Wilkinson TCI. Screening Strategies for the Discovery of Ion Channel Monoclonal Antibodies. ACTA ACUST UNITED AC 2018; 82:e44. [DOI: 10.1002/cpph.44] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Caroline S. Colley
- Antibody Discovery and Protein Engineering, MedImmune; Cambridge United Kingdom
| | - Elizabeth England
- Antibody Discovery and Protein Engineering, MedImmune; Cambridge United Kingdom
| | - John E. Linley
- Neuroscience, IMED Biotech Unit, AstraZeneca; Cambridge United Kingdom
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