1
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Dongol Y, Wilson DT, Daly NL, Cardoso FC, Lewis RJ. Structure-function and rational design of a spider toxin Ssp1a at human voltage-gated sodium channel subtypes. Front Pharmacol 2023; 14:1277143. [PMID: 38034993 PMCID: PMC10682951 DOI: 10.3389/fphar.2023.1277143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
The structure-function and optimization studies of NaV-inhibiting spider toxins have focused on developing selective inhibitors for peripheral pain-sensing NaV1.7. With several NaV subtypes emerging as potential therapeutic targets, structure-function analysis of NaV-inhibiting spider toxins at such subtypes is warranted. Using the recently discovered spider toxin Ssp1a, this study extends the structure-function relationships of NaV-inhibiting spider toxins beyond NaV1.7 to include the epilepsy target NaV1.2 and the pain target NaV1.3. Based on these results and docking studies, we designed analogues for improved potency and/or subtype-selectivity, with S7R-E18K-rSsp1a and N14D-P27R-rSsp1a identified as promising leads. S7R-E18K-rSsp1a increased the rSsp1a potency at these three NaV subtypes, especially at NaV1.3 (∼10-fold), while N14D-P27R-rSsp1a enhanced NaV1.2/1.7 selectivity over NaV1.3. This study highlights the challenge of developing subtype-selective spider toxin inhibitors across multiple NaV subtypes that might offer a more effective therapeutic approach. The findings of this study provide a basis for further rational design of Ssp1a and related NaSpTx1 homologs targeting NaV1.2, NaV1.3 and/or NaV1.7 as research tools and therapeutic leads.
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Affiliation(s)
- Yashad Dongol
- Centre for Chemistry and Drug Discovery, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David T. Wilson
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Norelle L. Daly
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Fernanda C. Cardoso
- Centre for Chemistry and Drug Discovery, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Richard J. Lewis
- Centre for Chemistry and Drug Discovery, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
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2
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Mateos DL, Yarov-Yarovoy V. Structural modeling of peptide toxin-ion channel interactions using RosettaDock. Proteins 2023. [PMID: 36729043 DOI: 10.1002/prot.26474] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/09/2022] [Accepted: 01/30/2023] [Indexed: 02/03/2023]
Abstract
Voltage-gated ion channels play essential physiological roles in action potential generation and propagation. Peptidic toxins from animal venoms target ion channels and provide useful scaffolds for the rational design of novel channel modulators with enhanced potency and subtype selectivity. Despite recent progress in obtaining experimental structures of peptide toxin-ion channel complexes, structural determination of peptide toxins bound to ion channels in physiologically important states remains challenging. Here we describe an application of RosettaDock approach to the structural modeling of peptide toxins interactions with ion channels. We tested this approach on 10 structures of peptide toxin-ion channel complexes and demonstrated that it can sample near-native structures in all tested cases. Our approach will be useful for improving the understanding of the molecular mechanism of natural peptide toxin modulation of ion channel gating and for the structural modeling of novel peptide-based ion channel modulators.
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Affiliation(s)
- Diego Lopez Mateos
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California, USA.,Biophysics Graduate Group, University of California Davis, Davis, California, USA
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California, USA.,Biophysics Graduate Group, University of California Davis, Davis, California, USA.,Department of Anesthesiology and Pain Medicine, University of California Davis, Davis, California, USA
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3
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Dongol Y, Choi PM, Wilson DT, Daly NL, Cardoso FC, Lewis RJ. Voltage-Gated Sodium Channel Modulation by a New Spider Toxin Ssp1a Isolated From an Australian Theraphosid. Front Pharmacol 2021; 12:795455. [PMID: 35002728 PMCID: PMC8740163 DOI: 10.3389/fphar.2021.795455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Given the important role of voltage-gated sodium (NaV) channel-modulating spider toxins in elucidating the function, pharmacology, and mechanism of action of therapeutically relevant NaV channels, we screened the venom from Australian theraphosid species against the human pain target hNaV1.7. Using assay-guided fractionation, we isolated a 33-residue inhibitor cystine knot (ICK) peptide (Ssp1a) belonging to the NaSpTx1 family. Recombinant Ssp1a (rSsp1a) inhibited neuronal hNaV subtypes with a rank order of potency hNaV1.7 > 1.6 > 1.2 > 1.3 > 1.1. rSsp1a inhibited hNaV1.7, hNaV1.2 and hNaV1.3 without significantly altering the voltage-dependence of activation, inactivation, or delay in recovery from inactivation. However, rSsp1a demonstrated voltage-dependent inhibition at hNaV1.7 and rSsp1a-bound hNaV1.7 opened at extreme depolarizations, suggesting rSsp1a likely interacted with voltage-sensing domain II (VSD II) of hNaV1.7 to trap the channel in its resting state. Nuclear magnetic resonance spectroscopy revealed key structural features of Ssp1a, including an amphipathic surface with hydrophobic and charged patches shown by docking studies to comprise the interacting surface. This study provides the basis for future structure-function studies to guide the development of subtype selective inhibitors.
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Affiliation(s)
- Yashad Dongol
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Phil M. Choi
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David T. Wilson
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Norelle L. Daly
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Fernanda C. Cardoso
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Richard J. Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
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4
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Diochot S. Pain-related toxins in scorpion and spider venoms: a face to face with ion channels. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20210026. [PMID: 34925480 PMCID: PMC8667759 DOI: 10.1590/1678-9199-jvatitd-2021-0026] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/10/2021] [Indexed: 12/12/2022] Open
Abstract
Pain is a common symptom induced during envenomation by spiders and scorpions.
Toxins isolated from their venom have become essential tools for studying the
functioning and physiopathological role of ion channels, as they modulate their
activity. In particular, toxins that induce pain relief effects can serve as a
molecular basis for the development of future analgesics in humans. This review
provides a summary of the different scorpion and spider toxins that directly
interact with pain-related ion channels, with inhibitory or stimulatory effects.
Some of these toxins were shown to affect pain modalities in different animal
models providing information on the role played by these channels in the pain
process. The close interaction of certain gating-modifier toxins with membrane
phospholipids close to ion channels is examined along with molecular approaches
to improve selectivity, affinity or bioavailability in vivo for
therapeutic purposes.
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Affiliation(s)
- Sylvie Diochot
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Centre National de la Recherche Scientifique (CNRS) UMR 7275 et Université Côte d'Azur (UCA), 06560 Valbonne, France. Institut de Pharmacologie Moléculaire et Cellulaire Centre National de la Recherche Scientifique Université Côte d'Azur Valbonne France
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5
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Lopez L, Montnach J, Oliveira-Mendes B, Khakh K, Thomas B, Lin S, Caumes C, Wesolowski S, Nicolas S, Servent D, Cohen C, Béroud R, Benoit E, De Waard M. Synthetic Analogues of Huwentoxin-IV Spider Peptide With Altered Human NaV1.7/NaV1.6 Selectivity Ratios. Front Cell Dev Biol 2021; 9:798588. [PMID: 34988086 PMCID: PMC8722715 DOI: 10.3389/fcell.2021.798588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/22/2021] [Indexed: 11/26/2022] Open
Abstract
Huwentoxin-IV (HwTx-IV), a peptide discovered in the venom of the Chinese bird spider Cyriopagopus schmidti, has been reported to be a potent antinociceptive compound due to its action on the genetically-validated NaV1.7 pain target. Using this peptide for antinociceptive applications in vivo suffers from one major drawback, namely its negative impact on the neuromuscular system. Although studied only recently, this effect appears to be due to an interaction between the peptide and the NaV1.6 channel subtype located at the presynaptic level. The aim of this work was to investigate how HwTx-IV could be modified in order to alter the original human (h) NaV1.7/NaV1.6 selectivity ratio of 23. Nineteen HwTx-IV analogues were chemically synthesized and tested for their blocking effects on the Na+ currents flowing through these two channel subtypes stably expressed in cell lines. Dose-response curves for these analogues were generated, thanks to the use of an automated patch-clamp system. Several key amino acid positions were targeted owing to the information provided by earlier structure-activity relationship (SAR) studies. Among the analogues tested, the potency of HwTx-IV E4K was significantly improved for hNaV1.6, leading to a decreased hNaV1.7/hNaV1.6 selectivity ratio (close to 1). Similar decreased selectivity ratios, but with increased potency for both subtypes, were observed for HwTx-IV analogues that combine a substitution at position 4 with a modification of amino acid 1 or 26 (HwTx-IV E1G/E4G and HwTx-IV E4K/R26Q). In contrast, increased selectivity ratios (>46) were obtained if the E4K mutation was combined to an additional double substitution (R26A/Y33W) or simply by further substituting the C-terminal amidation of the peptide by a carboxylated motif, linked to a marked loss of potency on hNaV1.6 in this latter case. These results demonstrate that it is possible to significantly modulate the selectivity ratio for these two channel subtypes in order to improve the potency of a given analogue for hNaV1.6 and/or hNaV1.7 subtypes. In addition, selective analogues for hNaV1.7, possessing better safety profiles, were produced to limit neuromuscular impairments.
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Affiliation(s)
- Ludivine Lopez
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Jérôme Montnach
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | | | | | | | - Sophia Lin
- Xenon Pharmaceuticals, Burnaby, BC, Canada
| | | | | | | | - Denis Servent
- Département Médicaments et Technologies pour La Santé (DMTS), Service d’Ingénierie Moléculaire pour La Santé (SIMoS), ERL CNRS/CEA, Institut des Sciences du Vivant Frédéric Joliot, CEA, Université Paris Saclay, Gif-sur-Yvette, France
| | | | | | - Evelyne Benoit
- Département Médicaments et Technologies pour La Santé (DMTS), Service d’Ingénierie Moléculaire pour La Santé (SIMoS), ERL CNRS/CEA, Institut des Sciences du Vivant Frédéric Joliot, CEA, Université Paris Saclay, Gif-sur-Yvette, France
| | - Michel De Waard
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
- Smartox Biotechnology, Saint-Egrève, France
- LabEx « Ion Channels, Science and Therapeutics », Valbonne, France
- *Correspondence: Michel De Waard,
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6
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Sanches K, Wai DCC, Norton RS. Conformational dynamics in peptide toxins: Implications for receptor interactions and molecular design. Toxicon 2021; 201:127-140. [PMID: 34454969 DOI: 10.1016/j.toxicon.2021.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 10/20/2022]
Abstract
Peptide toxins are potent and often exquisitely selective probes of the structure and function of ion channels and receptors, and are therefore of significant interest to the pharmaceutical and biotech industries as both pharmacological tools and therapeutic leads. The three-dimensional structures of peptide toxins are essential as a basis for understanding their structure-activity relationships and their binding to target receptors, as well as in guiding the design of analogues with modified potency and/or selectivity for key targets. NMR spectroscopy has played a key role in elucidating the structures of peptide toxins and probing their structure-function relationships. In this article, we highlight the additional important contribution of NMR to characterising the dynamics of peptide toxins. We also compare the information available from NMR measurements with that afforded by molecular dynamics simulations. We describe several examples of the importance of dynamics measurements over a range of timescales for understanding the structure-function relationships of peptide toxins and their receptor engagement. Peptide toxins that inhibit the voltage-gated potassium channel KV1.3 with pM affinities display different degrees of conformational flexibility, even though they contain multiple disulfide bonds, and this flexibility can affect the relative orientation of residues that have been shown to be critical for channel binding. Information on the dynamic properties of peptide toxins is important in the design of analogues or mimetics where receptor-bound structures are not available.
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Affiliation(s)
- Karoline Sanches
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia.
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7
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Hu H, Mawlawi SE, Zhao T, Deuis JR, Jami S, Vetter I, Lewis RJ, Cardoso FC. Engineering of a Spider Peptide via Conserved Structure-Function Traits Optimizes Sodium Channel Inhibition In Vitro and Anti-Nociception In Vivo. Front Mol Biosci 2021; 8:742457. [PMID: 34621788 PMCID: PMC8490825 DOI: 10.3389/fmolb.2021.742457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
Venom peptides are potent and selective modulators of voltage-gated ion channels that regulate neuronal function both in health and in disease. We previously identified the spider venom peptide Tap1a from the Venezuelan tarantula Theraphosa apophysis that targeted multiple voltage-gated sodium and calcium channels in visceral pain pathways and inhibited visceral mechano-sensing neurons contributing to irritable bowel syndrome. In this work, alanine scanning and domain activity analysis revealed Tap1a inhibited sodium channels by binding with nanomolar affinity to the voltage-sensor domain II utilising conserved structure-function features characteristic of spider peptides belonging to family NaSpTx1. In order to speed up the development of optimized NaV-targeting peptides with greater inhibitory potency and enhanced in vivo activity, we tested the hypothesis that incorporating residues identified from other optimized NaSpTx1 peptides into Tap1a could also optimize its potency for NaVs. Applying this approach, we designed the peptides Tap1a-OPT1 and Tap1a-OPT2 exhibiting significant increased potency for NaV1.1, NaV1.2, NaV1.3, NaV1.6 and NaV1.7 involved in several neurological disorders including acute and chronic pain, motor neuron disease and epilepsy. Tap1a-OPT1 showed increased potency for the off-target NaV1.4, while this off-target activity was absent in Tap1a-OPT2. This enhanced potency arose through a slowed off-rate mechanism. Optimized inhibition of NaV channels observed in vitro translated in vivo, with reversal of nocifensive behaviours in a murine model of NaV-mediated pain also enhanced by Tap1a-OPT. Molecular docking studies suggested that improved interactions within loops 3 and 4, and C-terminal of Tap1a-OPT and the NaV channel voltage-sensor domain II were the main drivers of potency optimization. Overall, the rationally designed peptide Tap1a-OPT displayed new and refined structure-function features which are likely the major contributors to its enhanced bioactive properties observed in vivo. This work contributes to the rapid engineering and optimization of potent spider peptides multi-targeting NaV channels, and the research into novel drugs to treat neurological diseases.
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Affiliation(s)
- H Hu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - S E Mawlawi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - T Zhao
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - J R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - S Jami
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - I Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.,School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | - R J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - F C Cardoso
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.,Centre for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, Australia
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8
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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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9
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Filipis L, Canepari M. Optical measurement of physiological sodium currents in the axon initial segment. J Physiol 2020; 599:49-66. [PMID: 33094478 DOI: 10.1113/jp280554] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/16/2020] [Indexed: 01/06/2023] Open
Abstract
KEY POINTS Τhe axonal Na+ fluorescence underlying an action potential in the axon initial segment was optically measured at unprecedented temporal resolution. The measurement allowed resolution of the kinetics of the Na+ current at different axonal locations. The distinct components of the Na+ current were correlated with the kinetics of the action potential. NEURON simulations from a modified published model qualitatively predicted the experimentally measured Na+ current. The present method permits the direct investigation of the kinetic behaviour of native Na+ channels under physiological and pathological conditions. ABSTRACT In most neurons of the mammalian central nervous system, the action potential (AP) is generated in the axon initial segment (AIS) by a fast Na+ current mediated by voltage-gated Na+ channels. While the axonal Na+ signal associated with the AP has been measured using fluorescent Na+ indicators, the insufficient resolution of these recordings has not allowed tracking the Na+ current kinetics underlying this fundamental event. In this article, we report the first optical measurement of Na+ currents in the AIS of pyramidal neurons of layer 5 of the somatosensory cortex from brain slices of the mouse. This measurement was obtained by achieving a temporal resolution of 100 μs in the Na+ imaging technique, with a pixel resolution of 0.5 μm, and by calculating the time-derivative of the Na+ change corrected for longitudinal diffusion. We identified a subthreshold current before the AP, a fast-inactivating current peaking during the rise of the AP and a non-inactivating current during the AP repolarization. We established a correlation between the kinetics of the non-inactivating current at different distances from the soma and the kinetics of the somatic AP. We quantitatively compared the experimentally measured Na+ current with the current obtained by computer simulation of published NEURON models, demonstrating how the present approach can lead to the correct estimate of the native behaviour of Na+ channels. Finally, we discuss how the present approach can be used to investigate the physiological or pathological function of different channel types during AP initiation and propagation.
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Affiliation(s)
- Luiza Filipis
- University of Grenoble Alpes, CNRS, LIPhy, Grenoble, F38000, France.,Laboratories of Excellence, Ion Channel Science and Therapeutics, France
| | - Marco Canepari
- University of Grenoble Alpes, CNRS, LIPhy, Grenoble, F38000, France.,Laboratories of Excellence, Ion Channel Science and Therapeutics, France.,Institut National de la Santé et Recherche Médicale, France
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10
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Gao S, Na R, Yang L, Yu H, Zhao X, Huang X. Investigation of binding modes of spider toxin–human voltage-gated sodium channel subtybe 1.7. J Biomol Struct Dyn 2020; 39:4981-4989. [DOI: 10.1080/07391102.2020.1783363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Shasha Gao
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Risong Na
- College of plant protection, Henan Agricultural University, Zhengzhou, P.R China
| | - Lianjuan Yang
- Department of Mycology, Shanghai Dermatology Hospital, Shanghai, China
| | - Hui Yu
- College of Science, Beihua Univesrity, Jilin, China
| | - Xi Zhao
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Xuri Huang
- College of plant protection, Henan Agricultural University, Zhengzhou, P.R China
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11
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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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12
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Agwa AJ, Tran P, Mueller A, Tran HNT, Deuis JR, Israel MR, McMahon KL, Craik DJ, Vetter I, Schroeder CI. Manipulation of a spider peptide toxin alters its affinity for lipid bilayers and potency and selectivity for voltage-gated sodium channel subtype 1.7. J Biol Chem 2020; 295:5067-5080. [PMID: 32139508 PMCID: PMC7152767 DOI: 10.1074/jbc.ra119.012281] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/03/2020] [Indexed: 02/05/2023] Open
Abstract
Huwentoxin-IV (HwTx-IV) is a gating modifier peptide toxin from spiders that has weak affinity for the lipid bilayer. As some gating modifier toxins have affinity for model lipid bilayers, a tripartite relationship among gating modifier toxins, voltage-gated ion channels, and the lipid membrane surrounding the channels has been proposed. We previously designed an HwTx-IV analogue (gHwTx-IV) with reduced negative charge and increased hydrophobic surface profile, which displays increased lipid bilayer affinity and in vitro activity at the voltage-gated sodium channel subtype 1.7 (NaV1.7), a channel targeted in pain management. Here, we show that replacements of the positively-charged residues that contribute to the activity of the peptide can improve gHwTx-IV's potency and selectivity for NaV1.7. Using HwTx-IV, gHwTx-IV, [R26A]gHwTx-IV, [K27A]gHwTx-IV, and [R29A]gHwTx-IV variants, we examined their potency and selectivity at human NaV1.7 and their affinity for the lipid bilayer. [R26A]gHwTx-IV consistently displayed the most improved potency and selectivity for NaV1.7, examined alongside off-target NaVs, compared with HwTx-IV and gHwTx-IV. The lipid affinity of each of the three novel analogues was weaker than that of gHwTx-IV, but stronger than that of HwTx-IV, suggesting a possible relationship between in vitro potency at NaV1.7 and affinity for lipid bilayers. In a murine NaV1.7 engagement model, [R26A]gHwTx-IV exhibited an efficacy comparable with that of native HwTx-IV. In summary, this study reports the development of an HwTx-IV analogue with improved in vitro selectivity for the pain target NaV1.7 and with an in vivo efficacy similar to that of native HwTx-IV.
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Poanna Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alexander Mueller
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Hue N T Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mathilde R Israel
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4103, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, USA
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13
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Neff RA, Flinspach M, Gibbs A, Shih AY, Minassian NA, Liu Y, Fellows R, Libiger O, Young S, Pennington MW, Hunter MJ, Wickenden AD. Comprehensive engineering of the tarantula venom peptide huwentoxin-IV to inhibit the human voltage-gated sodium channel hNav1.7. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49888-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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14
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Neff RA, Flinspach M, Gibbs A, Shih AY, Minassian NA, Liu Y, Fellows R, Libiger O, Young S, Pennington MW, Hunter MJ, Wickenden AD. Comprehensive engineering of the tarantula venom peptide huwentoxin-IV to inhibit the human voltage-gated sodium channel hNa v1.7. J Biol Chem 2019; 295:1315-1327. [PMID: 31871053 DOI: 10.1074/jbc.ra119.011318] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/20/2019] [Indexed: 02/04/2023] Open
Abstract
Pain is a significant public health burden in the United States, and current treatment approaches rely heavily on opioids, which often have limited efficacy and can lead to addiction. In humans, functional loss of the voltage-gated sodium channel Nav1.7 leads to pain insensitivity without deficits in the central nervous system. Accordingly, discovery of a selective Nav1.7 antagonist should provide an analgesic without abuse liability and an improved side-effect profile. Huwentoxin-IV, a component of tarantula venom, potently blocks sodium channels and is an attractive scaffold for engineering a Nav1.7-selective molecule. To define the functional impact of alterations in huwentoxin-IV sequence, we produced a library of 373 point mutants and tested them for Nav1.7 and Nav1.2 activity. We then combined favorable individual changes to produce combinatorial mutants that showed further improvements in Nav1.7 potency (E1N, E4D, Y33W, Q34S-Nav1.7 pIC50 = 8.1 ± 0.08) and increased selectivity over other Nav isoforms (E1N, R26K, Q34S, G36I, Nav1.7 pIC50 = 7.2 ± 0.1, Nav1.2 pIC50 = 6.1 ± 0.18, Nav1.3 pIC50 = 6.4 ± 1.0), Nav1.4 is inactive at 3 μm, and Nav1.5 is inactive at 10 μm We also substituted noncoded amino acids at select positions in huwentoxin-IV. Based on these results, we identify key determinants of huwentoxin's Nav1.7 inhibition and propose a model for huwentoxin-IV's interaction with Nav1.7. These findings uncover fundamental features of huwentoxin involved in Nav1.7 blockade, provide a foundation for additional optimization of this molecule, and offer a basis for the development of a safe and effective analgesic.
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Affiliation(s)
- Robert A Neff
- Neuroscience Discovery, Janssen Research and Development, LLC, San Diego, California 92121
| | - Mack Flinspach
- Biologics Research, Janssen Research and Development, LLC, San Diego, California 92121
| | - Alan Gibbs
- Structural Biology, Janssen Research and Development, LLC, Spring House, Pennsylvania 19477
| | - Amy Y Shih
- Discovery Chemistry-Computational Chemistry, Janssen Research and Development, LLC, San Diego, California 92121
| | - Natali A Minassian
- Neuroscience Discovery, Janssen Research and Development, LLC, San Diego, California 92121
| | - Yi Liu
- Neuroscience Discovery, Janssen Research and Development, LLC, San Diego, California 92121
| | - Ross Fellows
- Biologics Research, Janssen Research and Development, LLC, San Diego, California 92121
| | - Ondrej Libiger
- Translational Medicine and Early Development Statistics, Janssen Research and Development, LLC, San Diego, California 92121
| | - Stephanie Young
- Translational Medicine and Early Development Statistics, Janssen Research and Development, LLC, San Diego, California 92121
| | | | - Michael J Hunter
- Biologics Research, Janssen Research and Development, LLC, San Diego, California 92121
| | - Alan D Wickenden
- Molecular and Cellular Pharmacology, Janssen Research and Development, LLC, San Diego, California 92121
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15
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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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16
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Spider Knottin Pharmacology at Voltage-Gated Sodium Channels and Their Potential to Modulate Pain Pathways. Toxins (Basel) 2019; 11:toxins11110626. [PMID: 31671792 PMCID: PMC6891507 DOI: 10.3390/toxins11110626] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels (NaVs) are a key determinant of neuronal signalling. Neurotoxins from diverse taxa that selectively activate or inhibit NaV channels have helped unravel the role of NaV channels in diseases, including chronic pain. Spider venoms contain the most diverse array of inhibitor cystine knot (ICK) toxins (knottins). This review provides an overview on how spider knottins modulate NaV channels and describes the structural features and molecular determinants that influence their affinity and subtype selectivity. Genetic and functional evidence support a major involvement of NaV subtypes in various chronic pain conditions. The exquisite inhibitory properties of spider knottins over key NaV subtypes make them the best lead molecules for the development of novel analgesics to treat chronic pain.
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17
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Wu T, Wang M, Wu W, Luo Q, Jiang L, Tao H, Deng M. Spider venom peptides as potential drug candidates due to their anticancer and antinociceptive activities. J Venom Anim Toxins Incl Trop Dis 2019; 25:e146318. [PMID: 31210759 PMCID: PMC6551028 DOI: 10.1590/1678-9199-jvatitd-14-63-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 11/15/2018] [Indexed: 12/19/2022] Open
Abstract
Spider venoms are known to contain proteins and polypeptides that perform various
functions including antimicrobial, neurotoxic, analgesic, cytotoxic, necrotic,
and hemagglutinic activities. Currently, several classes of natural molecules
from spider venoms are potential sources of chemotherapeutics against tumor
cells. Some of the spider peptide toxins produce lethal effects on tumor cells
by regulating the cell cycle, activating caspase pathway or inactivating
mitochondria. Some of them also target the various types of ion channels
(including voltage-gated calcium channels, voltage-gated sodium channels, and
acid-sensing ion channels) among other pain-related targets. Herein we review
the structure and pharmacology of spider-venom peptides that are being used as
leads for the development of therapeutics against the pathophysiological
conditions including cancer and pain.
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Affiliation(s)
- Ting Wu
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China.,Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, China
| | - Meng Wang
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China.,Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, China
| | - Wenfang Wu
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China
| | - Qianxuan Luo
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China
| | - Liping Jiang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, China
| | - Huai Tao
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Meichun Deng
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China
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18
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Bajaj S, Han J. Venom-Derived Peptide Modulators of Cation-Selective Channels: Friend, Foe or Frenemy. Front Pharmacol 2019; 10:58. [PMID: 30863305 PMCID: PMC6399158 DOI: 10.3389/fphar.2019.00058] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 01/18/2019] [Indexed: 01/31/2023] Open
Abstract
Ion channels play a key role in our body to regulate homeostasis and conduct electrical signals. With the help of advances in structural biology, as well as the discovery of numerous channel modulators derived from animal toxins, we are moving toward a better understanding of the function and mode of action of ion channels. Their ubiquitous tissue distribution and the physiological relevancies of their opening and closing suggest that cation channels are particularly attractive drug targets, and years of research has revealed a variety of natural toxins that bind to these channels and alter their function. In this review, we provide an introductory overview of the major cation ion channels: potassium channels, sodium channels and calcium channels, describe their venom-derived peptide modulators, and how these peptides provide great research and therapeutic value to both basic and translational medical research.
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Affiliation(s)
- Saumya Bajaj
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jingyao Han
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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19
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Shen H, Liu D, Wu K, Lei J, Yan N. Structures of human Na v1.7 channel in complex with auxiliary subunits and animal toxins. Science 2019; 363:1303-1308. [PMID: 30765606 DOI: 10.1126/science.aaw2493] [Citation(s) in RCA: 288] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 01/29/2019] [Indexed: 12/18/2022]
Abstract
Voltage-gated sodium channel Nav1.7 represents a promising target for pain relief. Here we report the cryo-electron microscopy structures of the human Nav1.7-β1-β2 complex bound to two combinations of pore blockers and gating modifier toxins (GMTs), tetrodotoxin with protoxin-II and saxitoxin with huwentoxin-IV, both determined at overall resolutions of 3.2 angstroms. The two structures are nearly identical except for minor shifts of voltage-sensing domain II (VSDII), whose S3-S4 linker accommodates the two GMTs in a similar manner. One additional protoxin-II sits on top of the S3-S4 linker in VSDIV The structures may represent an inactivated state with all four VSDs "up" and the intracellular gate closed. The structures illuminate the path toward mechanistic understanding of the function and disease of Nav1.7 and establish the foundation for structure-aided development of analgesics.
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Affiliation(s)
- Huaizong Shen
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Dongliang Liu
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Kun Wu
- Medical Research Center, Beijing Key Laboratory of Cardiopulmonary Cerebral Resuscitation, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China
| | - Jianlin Lei
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Nieng Yan
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China. .,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
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20
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Wu B, Murray JK, Andrews KL, Sham K, Long J, Aral J, Ligutti J, Amagasu S, Liu D, Zou A, Min X, Wang Z, Ilch CP, Kornecook TJ, Lin MHJ, Be X, Miranda LP, Moyer BD, Biswas K. Discovery of Tarantula Venom-Derived NaV1.7-Inhibitory JzTx-V Peptide 5-Br-Trp24 Analogue AM-6120 with Systemic Block of Histamine-Induced Pruritis. J Med Chem 2018; 61:9500-9512. [DOI: 10.1021/acs.jmedchem.8b00736] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Xiaoshan Min
- Therapeutic Discovery, Amgen Research, Amgen Inc., 1120 Veterans Blvd, South San Francisco, California 94080, United States
| | - Zhulun Wang
- Therapeutic Discovery, Amgen Research, Amgen Inc., 1120 Veterans Blvd, South San Francisco, California 94080, United States
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21
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A complicated complex: Ion channels, voltage sensing, cell membranes and peptide inhibitors. Neurosci Lett 2018; 679:35-47. [DOI: 10.1016/j.neulet.2018.04.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/11/2018] [Accepted: 04/17/2018] [Indexed: 01/04/2023]
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22
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Abstract
Gating pore currents through the voltage-sensing domains (VSDs) of the skeletal muscle voltage-gated sodium channel NaV1.4 underlie hypokalemic periodic paralysis (HypoPP) type 2. Gating modifier toxins target ion channels by modifying the function of the VSDs. We tested the hypothesis that these toxins could function as blockers of the pathogenic gating pore currents. We report that a crab spider toxin Hm-3 from Heriaeus melloteei can inhibit gating pore currents due to mutations affecting the second arginine residue in the S4 helix of VSD-I that we have found in patients with HypoPP and describe here. NMR studies show that Hm-3 partitions into micelles through a hydrophobic cluster formed by aromatic residues and reveal complex formation with VSD-I through electrostatic and hydrophobic interactions with the S3b helix and the S3-S4 extracellular loop. Our data identify VSD-I as a specific binding site for neurotoxins on sodium channels. Gating modifier toxins may constitute useful hits for the treatment of HypoPP.
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23
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Zeng X, Li P, Chen B, Huang J, Lai R, Liu J, Rong M. Selective Closed-State Nav1.7 Blocker JZTX-34 Exhibits Analgesic Effects against Pain. Toxins (Basel) 2018; 10:toxins10020064. [PMID: 29393892 PMCID: PMC5848165 DOI: 10.3390/toxins10020064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/26/2018] [Accepted: 01/31/2018] [Indexed: 12/11/2022] Open
Abstract
Jingzhaotoxin-34 (JZTX-34) is a selective inhibitor of tetrodotoxin-sensitive (TTX-S) sodium channels. In this study, we found that JZTX-34 selectively acted on Nav1.7 with little effect on other sodium channel subtypes including Nav1.5. If the DIIS3-S4 linker of Nav1.5 is substituted by the correspond linker of Nav1.7, the sensitivity of Nav1.5 to JZTX-34 extremely increases to 1.05 µM. Meanwhile, a mutant D816R in the DIIS3-S4 linker of Nav1.7 decreases binding affinity of Nav1.7 to JZTX-34 about 32-fold. The reverse mutant R800D at the corresponding position in Nav1.5 greatly increased its binding affinity to JZTX-34. This implies that JZTX-34 binds to DIIS3-S4 linker of Nav1.7 and the critical residue of Nav1.7 is D816. Unlike β-scorpion toxin trapping sodium channel in an open state, activity of JZTX-34 requires the sodium channel to be in a resting state. JZTX-34 exhibits an obvious analgesic effect in a rodent pain model. Especially, it shows a longer duration and is more effective than morphine in hot pain models. In a formalin-induced pain model, JZTX-34 at dose of 2 mg/kg is equipotent with morphine (5 mg/kg) in the first phase and several-fold more effective than morphine in second phase. Taken together, our data indicate that JZTX-34 releases pain by selectively binding to the domain II voltage sensor of Nav1.7 in a closed configuration.
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Affiliation(s)
- Xiongzhi Zeng
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
| | - Pengpeng Li
- Life Sciences College of Nanjing Agricultural University, 210095, Jiangsu, China.
| | - Bo Chen
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
| | - Juan Huang
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
| | - Ren Lai
- Life Sciences College of Nanjing Agricultural University, 210095, Jiangsu, China.
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China.
| | - Jingze Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Science, Hebei Normal University, Shijiazhuang 050024, Hebei, China.
| | - Mingqiang Rong
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
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24
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Bang S, Yoo J, Gong X, Liu D, Han Q, Luo X, Chang W, Chen G, Im ST, Kim YH, Strong JA, Zhang MZ, Zhang JM, Lee SY, Ji RR. Differential Inhibition of Nav1.7 and Neuropathic Pain by Hybridoma-Produced and Recombinant Monoclonal Antibodies that Target Nav1.7 : Differential activities of Nav1.7-targeting monoclonal antibodies. Neurosci Bull 2018; 34:22-41. [PMID: 29333591 PMCID: PMC5799132 DOI: 10.1007/s12264-018-0203-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 12/18/2017] [Indexed: 12/21/2022] Open
Abstract
The voltage-gated Na+ channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na+ currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na+ currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na+ currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
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Affiliation(s)
- Sangsu Bang
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Jiho Yoo
- Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA
| | - Xingrui Gong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai, 200127, China
| | - Di Liu
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Qingjian Han
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Xin Luo
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Wonseok Chang
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
- Department of Physiology and Biophysics, College of Medicine, Eulji University, 143-5 Yongdu-Dong, Jung-Gu, Daejeon, 34824, Korea
| | - Gang Chen
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Sang-Taek Im
- Department of Physiology, College of Medicine, Gachon University, Incheon, 21999, Korea
| | - Yong Ho Kim
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
- Department of Physiology, College of Medicine, Gachon University, Incheon, 21999, Korea
| | - Judith A Strong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA
| | - Ma-Zhong Zhang
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai, 200127, China
| | - Jun-Ming Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA.
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA.
| | - Ru-Rong Ji
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA.
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25
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Pennington MW, Czerwinski A, Norton RS. Peptide therapeutics from venom: Current status and potential. Bioorg Med Chem 2017; 26:2738-2758. [PMID: 28988749 DOI: 10.1016/j.bmc.2017.09.029] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/14/2017] [Accepted: 09/19/2017] [Indexed: 12/19/2022]
Abstract
Peptides are recognized as being highly selective, potent and relatively safe as potential therapeutics. Peptides isolated from the venom of different animals satisfy most of these criteria with the possible exception of safety, but when isolated as single compounds and used at appropriate concentrations, venom-derived peptides can become useful drugs. Although the number of venom-derived peptides that have successfully progressed to the clinic is currently limited, the prospects for venom-derived peptides look very optimistic. As proteomic and transcriptomic approaches continue to identify new sequences, the potential of venom-derived peptides to find applications as therapeutics, cosmetics and insecticides grows accordingly.
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Affiliation(s)
| | - Andrzej Czerwinski
- Peptides International, Inc., 11621 Electron Drive, Louisville, KY 40299, USA
| | - Raymond S Norton
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, 3052, Australia
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26
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Insect-Active Toxins with Promiscuous Pharmacology from the African Theraphosid Spider Monocentropus balfouri. Toxins (Basel) 2017; 9:toxins9050155. [PMID: 28475112 PMCID: PMC5450703 DOI: 10.3390/toxins9050155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/24/2017] [Accepted: 04/28/2017] [Indexed: 01/22/2023] Open
Abstract
Many chemical insecticides are becoming less efficacious due to rising resistance in pest species, which has created much interest in the development of new, eco-friendly bioinsecticides. Since insects are the primary prey of most spiders, their venoms are a rich source of insect-active peptides that can be used as leads for new bioinsecticides or as tools to study molecular receptors that are insecticidal targets. In the present study, we isolated two insecticidal peptides, µ/ω-TRTX-Mb1a and -Mb1b, from venom of the African tarantula Monocentropus balfouri. Recombinant µ/ω-TRTX-Mb1a and -Mb1b paralyzed both Lucilia cuprina (Australian sheep blowfly) and Musca domestica (housefly), but neither peptide affected larvae of Helicoverpa armigera (cotton bollworms). Both peptides inhibited currents mediated by voltage-gated sodium (NaV) and calcium channels in Periplaneta americana (American cockroach) dorsal unpaired median neurons, and they also inhibited the cloned Blattella germanica (German cockroach) NaV channel (BgNaV1). An additional effect seen only with Mb1a on BgNaV1 was a delay in fast inactivation. Comparison of the NaV channel sequences of the tested insect species revealed that variations in the S1–S2 loops in the voltage sensor domains might underlie the differences in activity between different phyla.
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Wingerd JS, Mozar CA, Ussing CA, Murali SS, Chin YKY, Cristofori-Armstrong B, Durek T, Gilchrist J, Vaughan CW, Bosmans F, Adams DJ, Lewis RJ, Alewood PF, Mobli M, Christie MJ, Rash LD. The tarantula toxin β/δ-TRTX-Pre1a highlights the importance of the S1-S2 voltage-sensor region for sodium channel subtype selectivity. Sci Rep 2017; 7:974. [PMID: 28428547 PMCID: PMC5430537 DOI: 10.1038/s41598-017-01129-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/27/2017] [Indexed: 11/09/2022] Open
Abstract
Voltage-gated sodium (NaV) channels are essential for the transmission of pain signals in humans making them prime targets for the development of new analgesics. Spider venoms are a rich source of peptide modulators useful to study ion channel structure and function. Here we describe β/δ-TRTX-Pre1a, a 35-residue tarantula peptide that selectively interacts with neuronal NaV channels inhibiting peak current of hNaV1.1, rNaV1.2, hNaV1.6, and hNaV1.7 while concurrently inhibiting fast inactivation of hNaV1.1 and rNaV1.3. The DII and DIV S3-S4 loops of NaV channel voltage sensors are important for the interaction of Pre1a with NaV channels but cannot account for its unique subtype selectivity. Through analysis of the binding regions we ascertained that the variability of the S1-S2 loops between NaV channels contributes substantially to the selectivity profile observed for Pre1a, particularly with regards to fast inactivation. A serine residue on the DIV S2 helix was found to be sufficient to explain Pre1a’s potent and selective inhibitory effect on the fast inactivation process of NaV1.1 and 1.3. This work highlights that interactions with both S1-S2 and S3-S4 of NaV channels may be necessary for functional modulation, and that targeting the diverse S1-S2 region within voltage-sensing domains provides an avenue to develop subtype selective tools.
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Affiliation(s)
- Joshua S Wingerd
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Christine A Mozar
- Discipline of Pharmacology, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Christine A Ussing
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.,Novo Nordisk A/S, Copenhagen Area, Capital Region, Denmark
| | - Swetha S Murali
- Discipline of Pharmacology, University of Sydney, Camperdown, NSW, 2006, Australia.,Harvard Medical School, Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, United States
| | - Yanni K-Y Chin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Ben Cristofori-Armstrong
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Thomas Durek
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - John Gilchrist
- Department of Physiology and Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA
| | - Christopher W Vaughan
- Pain Management Research Institute, University of Sydney, St Leonards, NSW, 2006, Australia
| | - Frank Bosmans
- Department of Physiology and Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA
| | - David J Adams
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging & School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Macdonald J Christie
- Discipline of Pharmacology, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Lachlan D Rash
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia. .,School of Biomedical Sciences, The University of Queensland, St Lucia, 4072, QLD, Australia.
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28
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Agwa AJ, Henriques ST, Schroeder CI. Gating modifier toxin interactions with ion channels and lipid bilayers: Is the trimolecular complex real? Neuropharmacology 2017; 127:32-45. [PMID: 28400258 DOI: 10.1016/j.neuropharm.2017.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/15/2022]
Abstract
Spider peptide toxins have attracted attention because of their ability to target voltage-gated ion channels, which are involved in several pathologies including chronic pain and some cardiovascular conditions. A class of these peptides acts by modulating the gating mechanism of voltage-gated ion channels and are thus called gating modifier toxins (GMTs). In addition to their interactions with voltage-gated ion channels, some GMTs have affinity for lipid bilayers. This review discusses the potential importance of the cell membrane on the mode of action of GMTs. We propose that peptide-membrane interactions can anchor GMTs at the cell surface, thereby increasing GMT concentration in the vicinity of the channel binding site. We also propose that modulating peptide-membrane interactions might be useful for increasing the therapeutic potential of spider toxins. Furthermore, we explore the advantages and limitations of the methodologies currently used to examine peptide-membrane interactions. Although GMT-lipid membrane binding does not appear to be a requirement for the activity of all GMTs, it is an important feature, and future studies with GMTs should consider the trimolecular peptide-lipid membrane-channel complex. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sónia T Henriques
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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29
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Rahnama S, Deuis JR, Cardoso FC, Ramanujam V, Lewis RJ, Rash LD, King GF, Vetter I, Mobli M. The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant. PLoS One 2017; 12:e0173551. [PMID: 28301520 PMCID: PMC5354290 DOI: 10.1371/journal.pone.0173551] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/23/2017] [Indexed: 12/19/2022] Open
Abstract
Venom-derived peptides have attracted much attention as potential lead molecules for pharmaceutical development. A well-known example is Huwentoxin-IV (HwTx-IV), a peptide toxin isolated from the venom of the Chinese bird-eating spider Haplopelma schmitdi. HwTx-IV was identified as a potent blocker of a human voltage-gated sodium channel (hNaV1.7), which is a genetically validated analgesic target. The peptide was promising as it showed high potency at NaV1.7 (IC50 ~26 nM) and selectivity over the cardiac NaV subtype (NaV1.5). Mutagenesis studies aimed at optimising the potency of the peptide resulted in the development of a triple-mutant of HwTx-IV (E1G, E4G, Y33W, m3-HwTx-IV) with significantly increased potency against hNaV1.7 (IC50 = 0.4 ± 0.1 nM) without increased potency against hNaV1.5. The activity of m3-HwTx-IV against other NaV subtypes was, however, not investigated. Similarly, the structure of the mutant peptide was not characterised, limiting the interpretation of the observed increase in potency. In this study we produced isotope-labelled recombinant m3-HwTx-IV in E. coli, which enabled us to characterise the atomic-resolution structure and dynamics of the peptide by NMR spectroscopy. The results show that the structure of the peptide is not perturbed by the mutations, whilst the relaxation studies reveal that residues in the active site of the peptide undergo conformational exchange. Additionally, the NaV subtype selectivity of the recombinant peptide was characterised, revealing potent inhibition of neuronal NaV subtypes 1.1, 1.2, 1.3, 1.6 and 1.7. In parallel to the in vitro studies, we investigated NaV1.7 target engagement of the peptide in vivo using a rodent pain model, where m3-HwTx-IV dose-dependently suppressed spontaneous pain induced by the NaV1.7 activator OD1. Thus, our results provide further insight into the structure and dynamics of this class of peptides that may prove useful in guiding the development of inhibitors with improved selectivity for analgesic NaV subtypes.
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Affiliation(s)
- Sassan Rahnama
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Jennifer R. Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Fernanda C. Cardoso
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | | | - Richard J. Lewis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Lachlan D. Rash
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Glenn F. King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD, Australia
- * E-mail:
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30
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Liu D, Tseng M, Epstein LF, Green L, Chan B, Soriano B, Lim D, Pan O, Murawsky CM, King CT, Moyer BD. Evaluation of recombinant monoclonal antibody SVmab1 binding to Na V1.7 target sequences and block of human Na V1.7 currents. F1000Res 2016; 5:2764. [PMID: 27990272 PMCID: PMC5155501 DOI: 10.12688/f1000research.9918.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/11/2016] [Indexed: 01/16/2023] Open
Abstract
Identification of small and large molecule pain therapeutics that target the genetically validated voltage-gated sodium channel Na
V1.7 is a challenging endeavor under vigorous pursuit. The monoclonal antibody SVmab1 was recently published to bind the Na
V1.7 DII voltage sensor domain and block human Na
V1.7 sodium currents in heterologous cells. We produced purified SVmab1 protein based on publically available sequence information, and evaluated its activity in a battery of binding and functional assays. Herein, we report that our recombinant SVmAb1 does not bind peptide immunogen or purified Na
V1.7 DII voltage sensor domain via ELISA, and does not bind Na
V1.7 in live HEK293, U-2 OS, and CHO-K1 cells via FACS. Whole cell manual patch clamp electrophysiology protocols interrogating diverse Na
V1.7 gating states in HEK293 cells, revealed that recombinant SVmab1 does not block Na
V1.7 currents to an extent greater than observed with an isotype matched control antibody. Collectively, our results show that recombinant SVmab1 monoclonal antibody does not bind Na
V1.7 target sequences or specifically inhibit Na
V1.7 current.
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Affiliation(s)
- Dong Liu
- Neuroscience, Amgen Inc., Thousand Oaks, USA
| | | | | | | | | | - Brian Soriano
- Discovery Attribute Sciences, Amgen Inc., Thousand Oaks, USA
| | | | - Oscar Pan
- Amgen British Columbia, Burnaby, Canada
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31
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Lau CHY, King GF, Mobli M. Molecular basis of the interaction between gating modifier spider toxins and the voltage sensor of voltage-gated ion channels. Sci Rep 2016; 6:34333. [PMID: 27677715 PMCID: PMC5039624 DOI: 10.1038/srep34333] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/12/2016] [Indexed: 01/02/2023] Open
Abstract
Voltage-sensor domains (VSDs) are modular transmembrane domains of voltage-gated ion channels that respond to changes in membrane potential by undergoing conformational changes that are coupled to gating of the ion-conducting pore. Most spider-venom peptides function as gating modifiers by binding to the VSDs of voltage-gated channels and trapping them in a closed or open state. To understand the molecular basis underlying this mode of action, we used nuclear magnetic resonance to delineate the atomic details of the interaction between the VSD of the voltage-gated potassium channel KvAP and the spider-venom peptide VSTx1. Our data reveal that the toxin interacts with residues in an aqueous cleft formed between the extracellular S1-S2 and S3-S4 loops of the VSD whilst maintaining lipid interactions in the gaps formed between the S1-S4 and S2-S3 helices. The resulting network of interactions increases the energetic barrier to the conformational changes required for channel gating, and we propose that this is the mechanism by which gating modifier toxins inhibit voltage-gated ion channels.
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Affiliation(s)
- Carus H Y Lau
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD 4072, Australia
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32
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Herzig V, Ikonomopoulou M, Smith JJ, Dziemborowicz S, Gilchrist J, Kuhn-Nentwig L, Rezende FO, Moreira LA, Nicholson GM, Bosmans F, King GF. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami. Sci Rep 2016; 6:29538. [PMID: 27383378 PMCID: PMC4935840 DOI: 10.1038/srep29538] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/20/2016] [Indexed: 12/30/2022] Open
Abstract
The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1–S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species.
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Affiliation(s)
- Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Maria Ikonomopoulou
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jennifer J Smith
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Sławomir Dziemborowicz
- School of Medical &Molecular Biosciences, University of Technology, Sydney, NSW 2007, Australia
| | - John Gilchrist
- Department of Physiology &Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Lucia Kuhn-Nentwig
- Institute of Ecology &Evolution, University of Bern, CH 3012 Bern, Switzerland
| | | | | | - Graham M Nicholson
- School of Medical &Molecular Biosciences, University of Technology, Sydney, NSW 2007, Australia
| | - Frank Bosmans
- Department of Physiology &Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
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Murray JK, Long J, Zou A, Ligutti J, Andrews KL, Poppe L, Biswas K, Moyer BD, McDonough SI, Miranda LP. Single Residue Substitutions That Confer Voltage-Gated Sodium Ion Channel Subtype Selectivity in the NaV1.7 Inhibitory Peptide GpTx-1. J Med Chem 2016; 59:2704-17. [DOI: 10.1021/acs.jmedchem.5b01947] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Justin K. Murray
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Jason Long
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Anruo Zou
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Joseph Ligutti
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Kristin L. Andrews
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Leszek Poppe
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Kaustav Biswas
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Bryan D. Moyer
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Stefan I. McDonough
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Les P. Miranda
- Therapeutic Discovery and ‡Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
- Therapeutic Discovery and ∥Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States
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Tao H, Chen X, Lu M, Wu Y, Deng M, Zeng X, Liu Z, Liang S. Molecular determinant for the tarantula toxin Jingzhaotoxin-I slowing the fast inactivation of voltage-gated sodium channels. Toxicon 2015; 111:13-21. [PMID: 26721415 DOI: 10.1016/j.toxicon.2015.12.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/23/2015] [Accepted: 12/16/2015] [Indexed: 12/19/2022]
Abstract
Peptide toxins often have divergent pharmacological functions and are powerful tools for a deep review on the current understanding of the structure-function relationships of voltage-gated sodium channels (VGSCs). However, knowing about the interaction of site 3 toxins from tarantula venoms with VGSCs is not sufficient. In the present study, using whole-cell patch clamp technique, we determined the effects of Jingzhaotoxin-I (JZTX-I) on five VGSC subtypes expressed in HEK293 cells. The results showed that JZTX-I could inhibit the inactivation of rNav1.2, rNav1.3, rNav1.4, hNav1.5 and hNav1.7 channels with the IC50 of 870 ± 8 nM, 845 ± 4 nM, 339 ± 5 nM, 335 ± 9 nM, and 348 ± 6 nM, respectively. The affinity of the toxin interaction with subtypes (rNav1.4, hNav1.5, and hNav1.7) was only 2-fold higher than that for subtypes (rNav1.2 and rNav1.3). The toxin delayed the inactivation of VGSCs without affecting the activation and steady-state inactivation kinetics in the physiological range of voltages. Site-directed mutagenesis indicated that the toxin interacted with site 3 located at the extracellular S3-S4 linker of domain IV, and the acidic residue Asp at the position1609 in hNav1.5 was crucial for JZTX-I activity. Our results provide new insights in single key residue that allows toxins to recognize distinct ion channels with similar potency and enhance our understanding of the structure-function relationships of toxin-channel interactions.
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Affiliation(s)
- Huai Tao
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha 410208, Hunan, China; Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha 410208, Hunan, China.
| | - Xia Chen
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Min Lu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Yuanyuan Wu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Meichun Deng
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha 410013, Hunan, China
| | - Xiongzhi Zeng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Zhonghua Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Songping Liang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
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35
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Computational approaches for designing potent and selective analogs of peptide toxins as novel therapeutics. Future Med Chem 2015; 6:1645-58. [PMID: 25406005 DOI: 10.4155/fmc.14.98] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Peptide toxins provide valuable therapeutic leads for many diseases. As they bind to their targets with high affinity, potency is usually ensured. However, toxins also bind to off-target receptors, causing potential side effects. Thus, a major challenge in generating drugs from peptide toxins is ensuring their specificity for their intended targets. Computational methods can play an important role in solving such design problems through construction of accurate models of receptor-toxin complexes and calculation of binding free energies. Here we review the computational methods used for this purpose and their application to toxins targeting ion channels. We describe ShK and HsTX1 toxins, high-affinity blockers of the voltage-gated potassium channel Kv1.3, which could be developed as therapeutic agents for autoimmune diseases.
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36
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Cai T, Luo J, Meng E, Ding J, Liang S, Wang S, Liu Z. Mapping the interaction site for the tarantula toxin hainantoxin-IV (β-TRTX-Hn2a) in the voltage sensor module of domain II of voltage-gated sodium channels. Peptides 2015; 68:148-56. [PMID: 25218973 DOI: 10.1016/j.peptides.2014.09.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/01/2014] [Accepted: 09/02/2014] [Indexed: 01/22/2023]
Abstract
Peptide toxins often have pharmacological applications and are powerful tools for investigating the structure-function relationships of voltage-gated sodium channels (VGSCs). Although a group of potential VGSC inhibitors have been reported from tarantula venoms, little is known about the mechanism of their interaction with VGSCs. In this study, we showed that hainantoxin-IV (β-TRTX-Hn2a, HNTX-IV in brief), a 35-residue peptide from Ornithoctonus hainana venom, preferentially inhibited rNav1.2, rNav1.3 and hNav1.7 compared with rNav1.4 and hNav1.5. hNav1.7 was the most sensitive to HNTX-IV (IC50∼21nM). In contrast to many other tarantula toxins that affect VGSCs, HNTX-IV at subsaturating concentrations did not alter activation and inactivation kinetics in the physiological range of voltages, while very large depolarization above +70mV could partially activate toxin-bound hNav1.7 channel, indicating that HNTX-IV acts as a gating modifier rather than a pore blocker. Site-directed mutagenesis indicated that the toxin bound to site 4, which was located on the extracellular S3-S4 linker of hNav1.7 domain II. Mutants E753Q, D816N and E818Q of hNav1.7 decreased toxin affinity for hNav1.7 by 2.0-, 3.3- and 130-fold, respectively. In silico docking indicated that a three-toed claw substructure formed by residues with close contacts in the interface between HNTX-IV and hNav1.7 domain II stabilized the toxin-channel complex, impeding movement of the domain II voltage sensor and inhibiting hNav1.7 activation. Our data provide structural details for structure-based drug design and a useful template for the design of highly selective inhibitors of a specific subtype of VGSCs.
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Affiliation(s)
- Tianfu Cai
- College of Life Sciences, Hunan Normal University, Changsha, 410081 Hunan, China
| | - Ji Luo
- College of Life Sciences, Hunan Normal University, Changsha, 410081 Hunan, China
| | - Er Meng
- Research Center of Biological Information, College of Science, National University of Defense Technology, Changsha, 410073 Hunan, China
| | - Jiuping Ding
- Key Laboratory of Molecular Biophysics, Huazhong University of Science and Technology, Ministry of Education, College of Life Science and Technology, Wuhan, Hubei 430074, China
| | - Songping Liang
- College of Life Sciences, Hunan Normal University, Changsha, 410081 Hunan, China
| | - Sheng Wang
- Key Laboratory of Molecular Biophysics, Huazhong University of Science and Technology, Ministry of Education, College of Life Science and Technology, Wuhan, Hubei 430074, China.
| | - Zhonghua Liu
- College of Life Sciences, Hunan Normal University, Changsha, 410081 Hunan, China.
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Klint JK, Smith JJ, Vetter I, Rupasinghe DB, Er SY, Senff S, Herzig V, Mobli M, Lewis RJ, Bosmans F, King GF. Seven novel modulators of the analgesic target NaV 1.7 uncovered using a high-throughput venom-based discovery approach. Br J Pharmacol 2015; 172:2445-58. [PMID: 25754331 DOI: 10.1111/bph.13081] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 11/08/2014] [Accepted: 12/08/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Chronic pain is a serious worldwide health issue, with current analgesics having limited efficacy and dose-limiting side effects. Humans with loss-of-function mutations in the voltage-gated sodium channel NaV 1.7 (hNaV 1.7) are indifferent to pain, making hNaV 1.7 a promising target for analgesic development. Since spider venoms are replete with NaV channel modulators, we examined their potential as a source of hNaV 1.7 inhibitors. EXPERIMENTAL APPROACH We developed a high-throughput fluorescent-based assay to screen spider venoms against hNaV 1.7 and isolate 'hit' peptides. To examine the binding site of these peptides, we constructed a panel of chimeric channels in which the S3b-S4 paddle motif from each voltage sensor domain of hNaV 1.7 was transplanted into the homotetrameric KV 2.1 channel. KEY RESULTS We screened 205 spider venoms and found that 40% contain at least one inhibitor of hNaV 1.7. By deconvoluting 'hit' venoms, we discovered seven novel members of the NaSpTx family 1. One of these peptides, Hd1a (peptide μ-TRTX-Hd1a from venom of the spider Haplopelma doriae), inhibited hNaV 1.7 with a high level of selectivity over all other subtypes, except hNaV 1.1. We showed that Hd1a is a gating modifier that inhibits hNaV 1.7 by interacting with the S3b-S4 paddle motif in channel domain II. The structure of Hd1a, determined using heteronuclear NMR, contains an inhibitor cystine knot motif that is likely to confer high levels of chemical, thermal and biological stability. CONCLUSION AND IMPLICATIONS Our data indicate that spider venoms are a rich natural source of hNaV 1.7 inhibitors that might be useful leads for the development of novel analgesics.
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Affiliation(s)
- Julie K Klint
- Centre for Pain Research, Institute for Molecular Bioscience, St. Lucia, Qld, Australia
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Berkut AA, Peigneur S, Myshkin MY, Paramonov AS, Lyukmanova EN, Arseniev AS, Grishin EV, Tytgat J, Shenkarev ZO, Vassilevski AA. Structure of membrane-active toxin from crab spider Heriaeus melloteei suggests parallel evolution of sodium channel gating modifiers in Araneomorphae and Mygalomorphae. J Biol Chem 2014; 290:492-504. [PMID: 25352595 DOI: 10.1074/jbc.m114.595678] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We present a structural and functional study of a sodium channel activation inhibitor from crab spider venom. Hm-3 is an insecticidal peptide toxin consisting of 35 amino acid residues from the spider Heriaeus melloteei (Thomisidae). We produced Hm-3 recombinantly in Escherichia coli and determined its structure by NMR spectroscopy. Typical for spider toxins, Hm-3 was found to adopt the so-called "inhibitor cystine knot" or "knottin" fold stabilized by three disulfide bonds. Its molecule is amphiphilic with a hydrophobic ridge on the surface enriched in aromatic residues and surrounded by positive charges. Correspondingly, Hm-3 binds to both neutral and negatively charged lipid vesicles. Electrophysiological studies showed that at a concentration of 1 μm Hm-3 effectively inhibited a number of mammalian and insect sodium channels. Importantly, Hm-3 shifted the dependence of channel activation to more positive voltages. Moreover, the inhibition was voltage-dependent, and strong depolarizing prepulses attenuated Hm-3 activity. The toxin is therefore concluded to represent the first sodium channel gating modifier from an araneomorph spider and features a "membrane access" mechanism of action. Its amino acid sequence and position of the hydrophobic cluster are notably different from other known gating modifiers from spider venom, all of which are described from mygalomorph species. We hypothesize parallel evolution of inhibitor cystine knot toxins from Araneomorphae and Mygalomorphae suborders.
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Affiliation(s)
- Antonina A Berkut
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia, Moscow Institute of Physics and Technology (State University), 117303 Moscow, Russia, and
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven, 3000 Leuven, Belgium
| | - Mikhail Yu Myshkin
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia, Moscow Institute of Physics and Technology (State University), 117303 Moscow, Russia, and
| | - Alexander S Paramonov
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Ekaterina N Lyukmanova
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Alexander S Arseniev
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia, Moscow Institute of Physics and Technology (State University), 117303 Moscow, Russia, and
| | - Eugene V Grishin
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven, 3000 Leuven, Belgium
| | - Zakhar O Shenkarev
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Alexander A Vassilevski
- From the M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia,
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Kalia J, Milescu M, Salvatierra J, Wagner J, Klint JK, King GF, Olivera BM, Bosmans F. From foe to friend: using animal toxins to investigate ion channel function. J Mol Biol 2014; 427:158-175. [PMID: 25088688 DOI: 10.1016/j.jmb.2014.07.027] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/18/2014] [Accepted: 07/18/2014] [Indexed: 12/19/2022]
Abstract
Ion channels are vital contributors to cellular communication in a wide range of organisms, a distinct feature that renders this ubiquitous family of membrane-spanning proteins a prime target for toxins found in animal venom. For many years, the unique properties of these naturally occurring molecules have enabled researchers to probe the structural and functional features of ion channels and to define their physiological roles in normal and diseased tissues. To illustrate their considerable impact on the ion channel field, this review will highlight fundamental insights into toxin-channel interactions and recently developed toxin screening methods and practical applications of engineered toxins.
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Affiliation(s)
- Jeet Kalia
- Indian Institute of Science Education and Research Pune; Pune, Maharashtra 411 008 India
| | - Mirela Milescu
- Division of Biological Sciences; University of Missouri, Columbia, MO 65211 USA
| | - Juan Salvatierra
- Department of Physiology; Johns Hopkins University, School of Medicine, Baltimore, MD 21205 USA
| | - Jordan Wagner
- Department of Physiology; Johns Hopkins University, School of Medicine, Baltimore, MD 21205 USA
| | - Julie K Klint
- Institute for Molecular Bioscience; The University of Queensland, St. Lucia, QLD 4072 Australia
| | - Glenn F King
- Institute for Molecular Bioscience; The University of Queensland, St. Lucia, QLD 4072 Australia
| | | | - Frank Bosmans
- Department of Physiology; Johns Hopkins University, School of Medicine, Baltimore, MD 21205 USA.,Solomon H. Snyder Department of Neuroscience; Johns Hopkins University, School of Medicine, Baltimore, MD 21205 USA
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Bende NS, Dziemborowicz S, Mobli M, Herzig V, Gilchrist J, Wagner J, Nicholson GM, King GF, Bosmans F. A distinct sodium channel voltage-sensor locus determines insect selectivity of the spider toxin Dc1a. Nat Commun 2014; 5:4350. [PMID: 25014760 PMCID: PMC4115291 DOI: 10.1038/ncomms5350] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 06/10/2014] [Indexed: 12/16/2022] Open
Abstract
β-Diguetoxin-Dc1a (Dc1a) is a toxin from the desert bush spider Diguetia canities that incapacitates insects at concentrations that are non-toxic to mammals. Dc1a promotes opening of German cockroach voltage-gated sodium (Nav) channels (BgNav1), whereas human Nav channels are insensitive. Here, by transplanting commonly targeted S3b-S4 paddle motifs within BgNav1 voltage sensors into Kv2.1, we find that Dc1a interacts with the domain II voltage sensor. In contrast, Dc1a has little effect on sodium currents mediated by PaNav1 channels from the American cockroach even though their domain II paddle motifs are identical. When exploring regions responsible for PaNav1 resistance to Dc1a, we identified two residues within the BgNav1 domain II S1–S2 loop that when mutated to their PaNav1 counterparts drastically reduce toxin susceptibility. Overall, our results reveal a distinct region within insect Nav channels that helps determine Dc1a sensitivity, aconcept that will be valuable for the design of insect-selective insecticides.
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Affiliation(s)
- Niraj S Bende
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland QLD 4072, Australia
| | - Sławomir Dziemborowicz
- School of Medical and Molecular Biosciences, University of Technology, Sydney, New South Wales 2007, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland QLD 4072, Australia
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland QLD 4072, Australia
| | - John Gilchrist
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Jordan Wagner
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Graham M Nicholson
- School of Medical and Molecular Biosciences, University of Technology, Sydney, New South Wales 2007, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland QLD 4072, Australia
| | - Frank Bosmans
- 1] Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA [2] Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
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Zhang Y, Huang Y, He Q, Liu J, Luo J, Zhu L, Lu S, Huang P, Chen X, Zeng X, Liang S. Toxin diversity revealed by a transcriptomic study of Ornithoctonus huwena. PLoS One 2014; 9:e100682. [PMID: 24949878 PMCID: PMC4065081 DOI: 10.1371/journal.pone.0100682] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/26/2014] [Indexed: 12/31/2022] Open
Abstract
Spider venom comprises a mixture of compounds with diverse biological activities, which are used to capture prey and defend against predators. The peptide components bind a broad range of cellular targets with high affinity and selectivity, and appear to have remarkable structural diversity. Although spider venoms have been intensively investigated over the past few decades, venomic strategies to date have generally focused on high-abundance peptides. In addition, the lack of complete spider genomes or representative cDNA libraries has presented significant limitations for researchers interested in molecular diversity and understanding the genetic mechanisms of toxin evolution. In the present study, second-generation sequencing technologies, combined with proteomic analysis, were applied to determine the diverse peptide toxins in venom of the Chinese bird spider Ornithoctonus huwena. In total, 626 toxin precursor sequences were retrieved from transcriptomic data. All toxin precursors clustered into 16 gene superfamilies, which included six novel superfamilies and six novel cysteine patterns. A surprisingly high number of hypermutations and fragment insertions/deletions were detected, which accounted for the majority of toxin gene sequences with low-level expression. These mutations contribute to the formation of diverse cysteine patterns and highly variable isoforms. Furthermore, intraspecific venom variability, in combination with variable transcripts and peptide processing, contributes to the hypervariability of toxins in venoms, and associated rapid and adaptive evolution of toxins for prey capture and defense.
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Affiliation(s)
- Yiya Zhang
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yong Huang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Quanze He
- The State Key Laboratory of Genetic Engineering, Institute of Biomedical Science, Fudan University, Shanghai, China
| | - Jinyan Liu
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Ji Luo
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Li Zhu
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Shanshan Lu
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Pengfei Huang
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xinyi Chen
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiongzhi Zeng
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
- * E-mail: (ZX); (SL)
| | - Songping Liang
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
- * E-mail: (ZX); (SL)
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Xiao Y, Blumenthal K, Cummins TR. Gating-pore currents demonstrate selective and specific modulation of individual sodium channel voltage-sensors by biological toxins. Mol Pharmacol 2014; 86:159-67. [PMID: 24898004 DOI: 10.1124/mol.114.092338] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Voltage-gated sodium channels are critical determinants of nerve and muscle excitability. Although numerous toxins and small molecules target sodium channels, identifying the mechanisms of action is challenging. Here we used gating-pore currents selectively generated in each of the voltage-sensors from the four α-subunit domains (DI-DIV) to monitor the activity of individual voltage-sensors and to investigate the molecular determinants of sodium channel pharmacology. The tarantula toxin huwentoxin-IV (HWTX-IV), which inhibits sodium channel current, exclusively enhanced inward gating-pore currents through the DII voltage-sensor. By contrast, the tarantula toxin ProTx-II, which also inhibits sodium channel currents, altered the gating-pore currents in multiple voltage-sensors in a complex manner. Thus, whereas HWTX-IV inhibits central-pore currents by selectively trapping the DII voltage-sensor in the resting configuration, ProTx-II seems to inhibit central-pore currents by differentially altering the configuration of multiple voltage-sensors. The sea anemone toxin anthopleurin B, which impairs open-channel inactivation, exclusively enhanced inward gating-pore currents through the DIV voltage-sensor. This indicates that trapping the DIV voltage-sensor in the resting configuration selectively impairs open-channel inactivation. Furthermore, these data indicate that although activation of all four voltage-sensors is not required for central-pore current generation, activation of the DII voltage-sensor is crucial. Overall, our data demonstrate that gating-pore currents can determine the mechanism of action for sodium channel gating modifiers with high precision. We propose this approach could be adapted to identify the molecular mechanisms of action for gating modifiers of various voltage-gated ion channels.
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Affiliation(s)
- Yucheng Xiao
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana (Y.X., T.R.C.); Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York (K.B.)
| | - Kenneth Blumenthal
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana (Y.X., T.R.C.); Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York (K.B.)
| | - Theodore R Cummins
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana (Y.X., T.R.C.); Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York (K.B.)
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Abstract
Voltage-gated sodium (Nav) channels are essential contributors to neuronal excitability, making them the most commonly targeted ion channel family by toxins found in animal venoms. These molecules can be used to probe the functional aspects of Nav channels on a molecular level and to explore their physiological role in normal and diseased tissues. This chapter summarizes our existing knowledge of the mechanisms by which animal toxins influence Nav channels as well as their potential application in designing therapeutic drugs.
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44
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Rong M, Duan Z, Chen J, Li J, Xiao Y, Liang S. Native pyroglutamation of huwentoxin-IV: a post-translational modification that increases the trapping ability to the sodium channel. PLoS One 2013; 8:e65984. [PMID: 23826086 PMCID: PMC3691182 DOI: 10.1371/journal.pone.0065984] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 04/29/2013] [Indexed: 11/23/2022] Open
Abstract
Huwentoxin-IV (HWTX-IV), a tetrodotoxin-sensitive (TTX-s) sodium channel antagonist, is found in the venom of the Chinese spider Ornithoctonus huwena. A naturally modified HWTX-IV (mHWTX-IV), having a molecular mass 18 Da lower than HWTX-IV, has also been isolated from the venom of the same spider. By a combination of enzymatic fragmentation and MS/MS de novo sequencing, mHWTX-IV has been shown to have the same amino acid sequence as that of HWTX-IV, except that the N-terminal glutamic acid replaced by pyroglutamic acid. mHWTX-IV inhibited tetrodotoxin-sensitive voltage-gated sodium channels of dorsal root ganglion neurons with an IC50 nearly equal to native HWTX-IV. mHWTX-IV showed the same activation and inactivation kinetics seen for native HWTX-IV. In contrast with HWTX-IV, which dissociates at moderate voltage depolarization voltages (+50 mV, 180000 ms), mHWTX-IV inhibition of TTX-sensitive sodium channels is not reversed by strong depolarization voltages (+200 mV, 500 ms). Recovery of Nav1.7current was voltage-dependent and was induced by extreme depolarization in the presence of HWTX-IV, but no obvious current was elicited after application of mHWTX-IV. Our data indicate that the N-terminal modification of HWTX-IV gives the peptide toxin a greater ability to trap the voltage sensor in the sodium channel. Loss of a negative charge, caused by cyclization at the N-terminus, is a possible reason why the modified toxin binds much stronger. To our knowledge, this is the first report of a pyroglutamic acid residue in a spider toxin; this modification seems to increase the trapping ability of the voltage sensor in the sodium channel.
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Affiliation(s)
- Mingqiang Rong
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Zhigui Duan
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Juliang Chen
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Jianglin Li
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yuchen Xiao
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Songping Liang
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, China
- * E-mail:
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Minassian NA, Gibbs A, Shih AY, Liu Y, Neff RA, Sutton SW, Mirzadegan T, Connor J, Fellows R, Husovsky M, Nelson S, Hunter MJ, Flinspach M, Wickenden AD. Analysis of the structural and molecular basis of voltage-sensitive sodium channel inhibition by the spider toxin huwentoxin-IV (μ-TRTX-Hh2a). J Biol Chem 2013; 288:22707-20. [PMID: 23760503 DOI: 10.1074/jbc.m113.461392] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are essential to the normal function of the vertebrate nervous system. Aberrant function of VGSCs underlies a variety of disorders, including epilepsy, arrhythmia, and pain. A large number of animal toxins target these ion channels and may have significant therapeutic potential. Most of these toxins, however, have not been characterized in detail. Here, by combining patch clamp electrophysiology and radioligand binding studies with peptide mutagenesis, NMR structure determination, and molecular modeling, we have revealed key molecular determinants of the interaction between the tarantula toxin huwentoxin-IV and two VGSC isoforms, Nav1.7 and Nav1.2. Nine huwentoxin-IV residues (F6A, P11A, D14A, L22A, S25A, W30A, K32A, Y33A, and I35A) were important for block of Nav1.7 and Nav1.2. Importantly, molecular dynamics simulations and NMR studies indicated that folding was normal for several key mutants, suggesting that these amino acids probably make specific interactions with sodium channel residues. Additionally, we identified several amino acids (F6A, K18A, R26A, and K27A) that are involved in isoform-specific VGSC interactions. Our structural and functional data were used to model the docking of huwentoxin-IV into the domain II voltage sensor of Nav1.7. The model predicts that a hydrophobic patch composed of Trp-30 and Phe-6, along with the basic Lys-32 residue, docks into a groove formed by the Nav1.7 S1-S2 and S3-S4 loops. These results provide new insight into the structural and molecular basis of sodium channel block by huwentoxin-IV and may provide a basis for the rational design of toxin-based peptides with improved VGSC potency and/or selectivity.
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Affiliation(s)
- Natali A Minassian
- Department of Neuroscience Discovery, Janssen Research & Development, LLC, San Diego, California 92121, USA
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Revell JD, Lund PE, Linley JE, Metcalfe J, Burmeister N, Sridharan S, Jones C, Jermutus L, Bednarek MA. Potency optimization of Huwentoxin-IV on hNav1.7: a neurotoxin TTX-S sodium-channel antagonist from the venom of the Chinese bird-eating spider Selenocosmia huwena. Peptides 2013; 44:40-6. [PMID: 23523779 DOI: 10.1016/j.peptides.2013.03.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/06/2013] [Accepted: 03/06/2013] [Indexed: 11/23/2022]
Abstract
The spider venom peptide Huwentoxin-IV (HwTx-IV) 1 is a potent antagonist of hNav1.7 (IC50 determined herein as 17 ± 2 nM). Nav1.7 is a voltage-gated sodium channel involved in the generation and conduction of neuropathic and nociceptive pain signals. We prepared a number of HwTx-IV analogs as part of a structure-function study into Nav1.7 antagonism. The inhibitory potency of these analogs was determined by automated electrophysiology and is reported herein. In particular, the native residues Glu(1), Glu(4), Phe(6) and Tyr(33) were revealed as important activity modulators and several peptides bearing mutations in these positions showed significantly increased potency on hNav1.7 while maintaining the original selectivity profile of the wild-type peptide 1 on hNav1.5. Peptide 47 (Gly(1), Gly(4), Trp(33)-HwTx) demonstrated the largest potency increase on hNav1.7 (IC50 0.4 ± 0.1 nM).
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47
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Synthesis and biological characterization of synthetic analogs of Huwentoxin-IV (Mu-theraphotoxin-Hh2a), a neuronal tetrodotoxin-sensitive sodium channel inhibitor. Toxicon 2013; 71:57-65. [PMID: 23726857 DOI: 10.1016/j.toxicon.2013.05.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 05/12/2013] [Accepted: 05/15/2013] [Indexed: 11/22/2022]
Abstract
Huwentoxin-IV (HWTX-IV, also named Mu-theraphotoxin-Hh2a) is a typical inhibitor cystine knot peptide isolated from the venom of Chinese tarantula Ornithoctonus huwena and is found to inhibit tetrodotoxin-sensitive (TTX-S) sodium channels from mammalian sensory neurons. This peptide binds to neurotoxin receptor site 4 located at the extracellular S3-S4 linker of domain II in neuronal sodium channels. However, the molecular surface of HWTX-IV interaction with sodium channels remains unknown. In this study, we synthesized HWTX-IV and three mutants (T28D, R29A and Q34D) and characterized their functions on TTX-S sodium channels from adult rat dorsal root ganglion (DRG) neurons. Analysis of liquid chromatography, mass spectrometry and circular dichroism spectrum indicated that all four synthetic peptides are properly folded. Synthetic HWTX-IV exhibited the same activity as native HWTX-IV, while three mutations reduced toxin binding affinities by 10-200 fold, indicating that the basic or vicinal polar residues Thr²⁸, Arg²⁹, and Gln³⁴ in C-terminus might play critical roles in the interaction of HWTX-IV with TTX-S sodium channels.
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48
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Liu Z, Cai T, Zhu Q, Deng M, Li J, Zhou X, Zhang F, Li D, Li J, Liu Y, Hu W, Liang S. Structure and function of hainantoxin-III, a selective antagonist of neuronal tetrodotoxin-sensitive voltage-gated sodium channels isolated from the Chinese bird spider Ornithoctonus hainana. J Biol Chem 2013; 288:20392-403. [PMID: 23703613 DOI: 10.1074/jbc.m112.426627] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the present study, we investigated the structure and function of hainantoxin-III (HNTX-III), a 33-residue polypeptide from the venom of the spider Ornithoctonus hainana. It is a selective antagonist of neuronal tetrodotoxin-sensitive voltage-gated sodium channels. HNTX-III suppressed Nav1.7 current amplitude without significantly altering the activation, inactivation, and repriming kinetics. Short extreme depolarizations partially activated the toxin-bound channel, indicating voltage-dependent inhibition of HNTX-III. HNTX-III increased the deactivation of the Nav1.7 current after extreme depolarizations. The HNTX-III·Nav1.7 complex was gradually dissociated upon prolonged strong depolarizations in a voltage-dependent manner, and the unbound toxin rebound to Nav1.7 after a long repolarization. Moreover, analysis of chimeric channels showed that the DIIS3-S4 linker was critical for HNTX-III binding to Nav1.7. These data are consistent with HNTX-III interacting with Nav1.7 site 4 and trapping the domain II voltage sensor in the closed state. The solution structure of HNTX-III was determined by two-dimensional NMR and shown to possess an inhibitor cystine knot motif. Structural analysis indicated that certain basic, hydrophobic, and aromatic residues mainly localized in the C terminus may constitute an amphiphilic surface potentially involved in HNTX-III binding to Nav1.7. Taken together, our results show that HNTX-III is distinct from β-scorpion toxins and other β-spider toxins in its mechanism of action and binding specificity and affinity. The present findings contribute to our understanding of the mechanism of toxin-sodium channel interaction and provide a useful tool for the investigation of the structure and function of sodium channel isoforms and for the development of analgesics.
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Affiliation(s)
- Zhonghua Liu
- College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China.
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Knapp O, Nevin ST, Yasuda T, Lawrence N, Lewis RJ, Adams DJ. Biophysical properties of Na(v) 1.8/Na(v) 1.2 chimeras and inhibition by µO-conotoxin MrVIB. Br J Pharmacol 2012; 166:2148-60. [PMID: 22452751 DOI: 10.1111/j.1476-5381.2012.01955.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Voltage-gated sodium channels are expressed primarily in excitable cells and play a pivotal role in the initiation and propagation of action potentials. Nine subtypes of the pore-forming α-subunit have been identified, each with a distinct tissue distribution, biophysical properties and sensitivity to tetrodotoxin (TTX). Na(v) 1.8, a TTX-resistant (TTX-R) subtype, is selectively expressed in sensory neurons and plays a pathophysiological role in neuropathic pain. In comparison with TTX-sensitive (TTX-S) Na(v) α-subtypes in neurons, Na(v) 1.8 is most strongly inhibited by the µO-conotoxin MrVIB from Conus marmoreus. To determine which domain confers Na(v) 1.8 α-subunit its biophysical properties and MrVIB binding, we constructed various chimeric channels incorporating sequence from Na(v) 1.8 and the TTX-S Na(v) 1.2 using a domain exchange strategy. EXPERIMENTAL APPROACH Wild-type and chimeric Na(v) channels were expressed in Xenopus oocytes, and depolarization-activated Na⁺ currents were recorded using the two-electrode voltage clamp technique. KEY RESULTS MrVIB (1 µM) reduced Na(v) 1.2 current amplitude to 69 ± 12%, whereas Na(v) 1.8 current was reduced to 31 ± 3%, confirming that MrVIB has a binding preference for Na(v) 1.8. A similar reduction in Na⁺ current amplitude was observed when MrVIB was applied to chimeras containing the region extending from S6 segment of domain I through the S5-S6 linker of domain II of Na(v) 1.8. In contrast, MrVIB had only a small effect on Na⁺ current for chimeras containing the corresponding region of Na(v) 1.2. CONCLUSIONS AND IMPLICATIONS Taken together, these results suggest that domain II of Na(v) 1.8 is an important determinant of MrVIB affinity, highlighting a region of the α-subunit that may allow further nociceptor-specific ligand targeting.
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Affiliation(s)
- O Knapp
- Health Innovations Research Institute, RMIT University, Melbourne, Vic, Australia
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Peigneur S, Béress L, Möller C, Marí F, Forssmann W, Tytgat J. A natural point mutation changes both target selectivity and mechanism of action of sea anemone toxins. FASEB J 2012; 26:5141-51. [DOI: 10.1096/fj.12-218479] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Steve Peigneur
- Laboratory of ToxicologyUniversity of Leuven (Katholieke Universiteit Leuven)LeuvenBelgium
| | - László Béress
- Department of Immunology and RheumatologyHannover Medical UniversityHannoverGermany
- Pharis Biotec GmbHHannoverGermany
| | - Carolina Möller
- Department of Chemistry and BiochemistryFlorida Atlantic UniversityBoca RatonFloridaUSA
| | - Frank Marí
- Department of Chemistry and BiochemistryFlorida Atlantic UniversityBoca RatonFloridaUSA
| | - Wolf‐Georg Forssmann
- Department of Immunology and RheumatologyHannover Medical UniversityHannoverGermany
- Pharis Biotec GmbHHannoverGermany
| | - Jan Tytgat
- Laboratory of ToxicologyUniversity of Leuven (Katholieke Universiteit Leuven)LeuvenBelgium
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