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Dashevsky D, Harris RJ, Zdenek CN, Benard-Valle M, Alagón A, Portes-Junior JA, Tanaka-Azevedo AM, Grego KF, Sant'Anna SS, Frank N, Fry BG. Red-on-Yellow Queen: Bio-Layer Interferometry Reveals Functional Diversity Within Micrurus Venoms and Toxin Resistance in Prey Species. J Mol Evol 2024; 92:317-328. [PMID: 38814340 PMCID: PMC11168994 DOI: 10.1007/s00239-024-10176-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 05/03/2024] [Indexed: 05/31/2024]
Abstract
Snakes in the family Elapidae largely produce venoms rich in three-finger toxins (3FTx) that bind to the α 1 subunit of nicotinic acetylcholine receptors (nAChRs), impeding ion channel activity. These neurotoxins immobilize the prey by disrupting muscle contraction. Coral snakes of the genus Micrurus are specialist predators who produce many 3FTx, making them an interesting system for examining the coevolution of these toxins and their targets in prey animals. We used a bio-layer interferometry technique to measure the binding interaction between 15 Micrurus venoms and 12 taxon-specific mimotopes designed to resemble the orthosteric binding region of the muscular nAChR subunit. We found that Micrurus venoms vary greatly in their potency on this assay and that this variation follows phylogenetic patterns rather than previously reported patterns of venom composition. The long-tailed Micrurus tend to have greater binding to nAChR orthosteric sites than their short-tailed relatives and we conclude this is the likely ancestral state. The repeated loss of this activity may be due to the evolution of 3FTx that bind to other regions of the nAChR. We also observed variations in the potency of the venoms depending on the taxon of the target mimotope. Rather than a pattern of prey-specificity, we found that mimotopes modeled after snake nAChRs are less susceptible to Micrurus venoms and that this resistance is partly due to a characteristic tryptophan → serine mutation within the orthosteric site in all snake mimotopes. This resistance may be part of a Red Queen arms race between coral snakes and their prey.
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Affiliation(s)
- Daniel Dashevsky
- Australian National Insect Collection, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT, 2601, Australia.
| | - Richard J Harris
- Venom Evolution Lab, School of the Environment, The University of Queensland, Saint Lucia, QLD, 4072, Australia
- Australian Institute of Marine Science, Cape Cleveland, QLD, 4810, Australia
| | - Christina N Zdenek
- Celine Frere Group, School of the Environment, The University of Queensland, Saint Lucia, QLD, 4072, Australia
| | - Melisa Benard-Valle
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800, Kongens Lyngby, Region Hovedstaden, Denmark
| | - Alejandro Alagón
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico
| | - José A Portes-Junior
- Laboratório de Coleções Zoológicas, Instituto Butantan, São Paulo, São Paulo, 05503-900, Brazil
| | - Anita M Tanaka-Azevedo
- Laboratório de Herpetologia, Instituto Butantan, São Paulo, São Paulo, 05503-900, Brazil
| | - Kathleen F Grego
- Laboratório de Herpetologia, Instituto Butantan, São Paulo, São Paulo, 05503-900, Brazil
| | - Sávio S Sant'Anna
- Laboratório de Herpetologia, Instituto Butantan, São Paulo, São Paulo, 05503-900, Brazil
| | - Nathaniel Frank
- MToxins Venom Lab, 717 Oregon Street, Oshkosh, WI, 54902, USA
| | - Bryan G Fry
- Venom Evolution Lab, School of the Environment, The University of Queensland, Saint Lucia, QLD, 4072, Australia
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2
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Roman-Ramos H, Prieto-da-Silva ÁRB, Dellê H, Floriano RS, Dias L, Hyslop S, Schezaro-Ramos R, Servent D, Mourier G, de Oliveira JL, Lemes DE, Costa-Lotufo LV, Oliveira JS, Menezes MC, Markus RP, Ho PL. The Cloning and Characterization of a Three-Finger Toxin Homolog (NXH8) from the Coralsnake Micrurus corallinus That Interacts with Skeletal Muscle Nicotinic Acetylcholine Receptors. Toxins (Basel) 2024; 16:164. [PMID: 38668589 PMCID: PMC11054780 DOI: 10.3390/toxins16040164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/04/2024] [Accepted: 03/20/2024] [Indexed: 04/29/2024] Open
Abstract
Coralsnakes (Micrurus spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx). Due to difficulties in venom extraction and availability, research on coralsnake venoms is still very limited when compared to that of other Elapidae snakes like cobras, kraits, and mambas. In this study, two previously described 3FTx from the venom of M. corallinus, NXH1 (3SOC1_MICCO), and NXH8 (3NO48_MICCO) were characterized. Using in silico, in vitro, and ex vivo experiments, the biological activities of these toxins were predicted and evaluated. The results showed that only NXH8 was capable of binding to skeletal muscle cells and modulating the activity of nAChRs in nerve-diaphragm preparations. These effects were antagonized by anti-rNXH8 or antielapidic sera. Sequence analysis revealed that the NXH1 toxin possesses eight cysteine residues and four disulfide bonds, while the NXH8 toxin has a primary structure similar to that of non-conventional 3FTx, with an additional disulfide bond on the first loop. These findings add more information related to the structural diversity present within the 3FTx class, while expanding our understanding of the mechanisms of the toxicity of this coralsnake venom and opening new perspectives for developing more effective therapeutic interventions.
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Affiliation(s)
- Henrique Roman-Ramos
- Laboratório de Biotecnologia, Programa de Pós-Graduação em Medicina, Universidade Nove de Julho (UNINOVE), São Paulo 01504-001, SP, Brazil; (H.D.); (J.L.d.O.); (D.E.L.)
| | | | - Humberto Dellê
- Laboratório de Biotecnologia, Programa de Pós-Graduação em Medicina, Universidade Nove de Julho (UNINOVE), São Paulo 01504-001, SP, Brazil; (H.D.); (J.L.d.O.); (D.E.L.)
| | - Rafael S. Floriano
- Laboratório de Toxinologia e Estudos Cardiovasculares, Universidade do Oeste Paulista (UNOESTE), Presidente Prudente 19067-175, SP, Brazil;
| | - Lourdes Dias
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil; (L.D.); (S.H.); (R.S.-R.)
| | - Stephen Hyslop
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil; (L.D.); (S.H.); (R.S.-R.)
| | - Raphael Schezaro-Ramos
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil; (L.D.); (S.H.); (R.S.-R.)
| | - Denis Servent
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS), Département Médicaments et Technologies pour la Santé, Université Paris Saclay, Commissariat à l’énergie Atomique et aux Énergies Alternatives (CEA), F-91191 Gif sur Yvette, France; (D.S.); (G.M.)
| | - Gilles Mourier
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS), Département Médicaments et Technologies pour la Santé, Université Paris Saclay, Commissariat à l’énergie Atomique et aux Énergies Alternatives (CEA), F-91191 Gif sur Yvette, France; (D.S.); (G.M.)
| | - Jéssica Lopes de Oliveira
- Laboratório de Biotecnologia, Programa de Pós-Graduação em Medicina, Universidade Nove de Julho (UNINOVE), São Paulo 01504-001, SP, Brazil; (H.D.); (J.L.d.O.); (D.E.L.)
| | - Douglas Edgard Lemes
- Laboratório de Biotecnologia, Programa de Pós-Graduação em Medicina, Universidade Nove de Julho (UNINOVE), São Paulo 01504-001, SP, Brazil; (H.D.); (J.L.d.O.); (D.E.L.)
| | - Letícia V. Costa-Lotufo
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo 05508-000, SP, Brazil;
| | - Jane S. Oliveira
- Centro de Biotecnologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil;
| | | | - Regina P. Markus
- Laboratório de Cronofarmacologia, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo 05508-090, SP, Brazil;
| | - Paulo Lee Ho
- Centro Bioindustrial, Instituto Butantan, São Paulo 05503-900, SP, Brazil;
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3
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Munafó JP, Biscussi B, Obiol D, Costabel M, Bouzat C, Murray AP, Antollini S. New Multitarget Molecules Derived from Caffeine as Potentiators of the Cholinergic System. ACS Chem Neurosci 2024; 15:994-1009. [PMID: 38407056 DOI: 10.1021/acschemneuro.3c00710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024] Open
Abstract
Cholinergic deficit is a characteristic factor of several pathologies, such as myasthenia gravis, some types of congenital myasthenic syndromes, and Alzheimer's Disease. Two molecular targets for its treatment are acetylcholinesterase (AChE) and nicotinic acetylcholine receptor (nAChR). In previous studies, we found that caffeine behaves as a partial nAChR agonist and confirmed that it inhibits AChE. Here, we present new bifunctional caffeine derivatives consisting of a theophylline ring connected to amino groups by different linkers. All of them were more potent AChE inhibitors than caffeine. Furthermore, although some of them also activated muscle nAChR as partial agonists, not all of them stabilized nAChR in its desensitized conformation. To understand the molecular mechanism underlying these results, we performed docking studies on AChE and nAChR. The nAChR agonist behavior of the compounds depends on their accessory group, whereas their ability to stabilize the receptor in a desensitized state depends on the interactions of the linker at the binding site. Our results show that the new compounds can inhibit AChE and activate nAChR with greater potency than caffeine and provide further information on the modulation mechanisms of pharmacological targets for the design of novel therapeutic interventions in cholinergic deficit.
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Affiliation(s)
- Juan Pablo Munafó
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
| | - Brunella Biscussi
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Diego Obiol
- Grupo de Biofísica, Instituto de Física del Sur, Departamento de Física, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Marcelo Costabel
- Grupo de Biofísica, Instituto de Física del Sur, Departamento de Física, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
| | - Ana Paula Murray
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Silvia Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
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4
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Menzies SK, Arinto-Garcia R, Amorim FG, Cardoso IA, Abada C, Crasset T, Durbesson F, Edge RJ, El-Kazzi P, Hall S, Redureau D, Stenner R, Boldrini-França J, Sun H, Roldão A, Alves PM, Harrison RA, Vincentelli R, Berger I, Quinton L, Casewell NR, Schaffitzel C. ADDovenom: Thermostable Protein-Based ADDomer Nanoparticles as New Therapeutics for Snakebite Envenoming. Toxins (Basel) 2023; 15:673. [PMID: 38133177 PMCID: PMC10747859 DOI: 10.3390/toxins15120673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/13/2023] [Accepted: 11/23/2023] [Indexed: 12/23/2023] Open
Abstract
Snakebite envenoming can be a life-threatening medical emergency that requires prompt medical intervention to neutralise the effects of venom toxins. Each year up to 138,000 people die from snakebites and threefold more victims suffer life-altering disabilities. The current treatment of snakebite relies solely on antivenom-polyclonal antibodies isolated from the plasma of hyperimmunised animals-which is associated with numerous deficiencies. The ADDovenom project seeks to deliver a novel snakebite therapy, through the use of an innovative protein-based scaffold as a next-generation antivenom. The ADDomer is a megadalton-sized, thermostable synthetic nanoparticle derived from the adenovirus penton base protein; it has 60 high-avidity binding sites to neutralise venom toxins. Here, we outline our experimental strategies to achieve this goal using state-of-the-art protein engineering, expression technology and mass spectrometry, as well as in vitro and in vivo venom neutralisation assays. We anticipate that the approaches described here will produce antivenom with unparalleled efficacy, safety and affordability.
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Affiliation(s)
- Stefanie K. Menzies
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Raquel Arinto-Garcia
- iBET, Instituto de Biologia Experimental e Technológica, Apartado 12, 2781-901 Oeiras, Portugal
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Fernanda Gobbi Amorim
- Mass Spectrometry Laboratory, MolSys Research Unit, Allée du six Aout 11, Quartier Agora, Liège Université, 4000 Liège, Belgium
| | - Iara Aimê Cardoso
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Camille Abada
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Thomas Crasset
- Mass Spectrometry Laboratory, MolSys Research Unit, Allée du six Aout 11, Quartier Agora, Liège Université, 4000 Liège, Belgium
| | - Fabien Durbesson
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13009 Marseille, France
| | - Rebecca J. Edge
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Priscila El-Kazzi
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13009 Marseille, France
| | - Sophie Hall
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock’s Close, Bristol BS8 1TS, UK
| | - Damien Redureau
- Mass Spectrometry Laboratory, MolSys Research Unit, Allée du six Aout 11, Quartier Agora, Liège Université, 4000 Liège, Belgium
| | - Richard Stenner
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock’s Close, Bristol BS8 1TS, UK
| | - Johara Boldrini-França
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock’s Close, Bristol BS8 1TS, UK
| | - Huan Sun
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock’s Close, Bristol BS8 1TS, UK
| | - António Roldão
- iBET, Instituto de Biologia Experimental e Technológica, Apartado 12, 2781-901 Oeiras, Portugal
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Paula M. Alves
- iBET, Instituto de Biologia Experimental e Technológica, Apartado 12, 2781-901 Oeiras, Portugal
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Robert A. Harrison
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Renaud Vincentelli
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13009 Marseille, France
| | - Imre Berger
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock’s Close, Bristol BS8 1TS, UK
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, Allée du six Aout 11, Quartier Agora, Liège Université, 4000 Liège, Belgium
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Christiane Schaffitzel
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
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5
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Palermo G, Schouten WM, Alonso LL, Ulens C, Kool J, Slagboom J. Acetylcholine-Binding Protein Affinity Profiling of Neurotoxins in Snake Venoms with Parallel Toxin Identification. Int J Mol Sci 2023; 24:16769. [PMID: 38069093 PMCID: PMC10706727 DOI: 10.3390/ijms242316769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Snakebite is considered a concerning issue and a neglected tropical disease. Three-finger toxins (3FTxs) in snake venoms primarily cause neurotoxic effects since they have high affinity for nicotinic acetylcholine receptors (nAChRs). Their small molecular size makes 3FTxs weakly immunogenic and therefore not appropriately targeted by current antivenoms. This study aims at presenting and applying an analytical method for investigating the therapeutic potential of the acetylcholine-binding protein (AChBP), an efficient nAChR mimic that can capture 3FTxs, for alternative treatment of elapid snakebites. In this analytical methodology, snake venom toxins were separated and characterised using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) and high-throughput venomics. By subsequent nanofractionation analytics, binding profiling of toxins to the AChBP was achieved with a post-column plate reader-based fluorescence-enhancement ligand displacement bioassay. The integrated method was established and applied to profiling venoms of six elapid snakes (Naja mossambica, Ophiophagus hannah, Dendroaspis polylepis, Naja kaouthia, Naja haje and Bungarus multicinctus). The methodology demonstrated that the AChBP is able to effectively bind long-chain 3FTxs with relatively high affinity, but has low or no binding affinity towards short-chain 3FTxs, and as such provides an efficient analytical platform to investigate binding affinity of 3FTxs to the AChBP and mutants thereof and to rapidly identify bound toxins.
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Affiliation(s)
- Giulia Palermo
- Centre for Analytical Sciences Amsterdam (CASA), 1012 WX Amsterdam, The Netherlands; (G.P.); (W.M.S.); (L.L.A.)
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Wietse M. Schouten
- Centre for Analytical Sciences Amsterdam (CASA), 1012 WX Amsterdam, The Netherlands; (G.P.); (W.M.S.); (L.L.A.)
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Luis Lago Alonso
- Centre for Analytical Sciences Amsterdam (CASA), 1012 WX Amsterdam, The Netherlands; (G.P.); (W.M.S.); (L.L.A.)
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, 3000 Leuven, Belgium;
| | - Jeroen Kool
- Centre for Analytical Sciences Amsterdam (CASA), 1012 WX Amsterdam, The Netherlands; (G.P.); (W.M.S.); (L.L.A.)
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Julien Slagboom
- Centre for Analytical Sciences Amsterdam (CASA), 1012 WX Amsterdam, The Netherlands; (G.P.); (W.M.S.); (L.L.A.)
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
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6
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Patel RN, Clare RH, Ledsgaard L, Nys M, Kool J, Laustsen AH, Ulens C, Casewell NR. An in vitro assay to investigate venom neurotoxin activity on muscle-type nicotinic acetylcholine receptor activation and for the discovery of toxin-inhibitory molecules. Biochem Pharmacol 2023; 216:115758. [PMID: 37604290 PMCID: PMC10570928 DOI: 10.1016/j.bcp.2023.115758] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Snakebite envenoming is a neglected tropical disease that causes over 100,000 deaths annually. Envenomings result in variable pathologies, but systemic neurotoxicity is among the most serious and is currently only treated with difficult to access and variably efficacious commercial antivenoms. Venom-induced neurotoxicity is often caused by α-neurotoxins antagonising the muscle-type nicotinic acetylcholine receptor (nAChR), a ligand-gated ion channel. Discovery of therapeutics targeting α-neurotoxins is hampered by relying on binding assays that do not reveal restoration of receptor activity or more costly and/or lower throughput electrophysiology-based approaches. Here, we report the validation of a screening assay for nAChR activation using immortalised TE671 cells expressing the γ-subunit containing muscle-type nAChR and a fluorescent dye that reports changes in cell membrane potential. Assay validation using traditional nAChR agonists and antagonists, which either activate or block ion fluxes, was consistent with previous studies. We then characterised antagonism of the nAChR by a variety of elapid snake venoms that cause muscle paralysis in snakebite victims, before defining the toxin-inhibiting activities of commercial antivenoms, and new types of snakebite therapeutic candidates, namely monoclonal antibodies, decoy receptors, and small molecules. Our findings show robust evidence of assay uniformity across 96-well plates and highlight the amenability of this approach for the future discovery of new snakebite therapeutics via screening campaigns. The described assay therefore represents a useful first-step approach for identifying α-neurotoxins and their inhibitors in the context of snakebite envenoming, and it should provide wider value for studying modulators of nAChR activity from other sources.
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Affiliation(s)
- Rohit N Patel
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Rachel H Clare
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Line Ledsgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Mieke Nys
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Jeroen Kool
- AIMMS Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Netherlands
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK.
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7
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Zhou K, Luo W, Liu T, Ni Y, Qin Z. Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications. Toxins (Basel) 2022; 15:18. [PMID: 36668838 PMCID: PMC9865788 DOI: 10.3390/toxins15010018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotoxins generally inhibit or promote the release of neurotransmitters or bind to receptors that are located in the pre- or post-synaptic membranes, thereby affecting physiological functions of synapses and affecting biological processes. With more and more research on the toxins of various origins, many neurotoxins are now widely used in clinical treatment and have demonstrated good therapeutic outcomes. This review summarizes the structural properties and potential pharmacological effects of neurotoxins acting on different components of the synapse, as well as their important clinical applications, thus could be a useful reference for researchers and clinicians in the study of neurotoxins.
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Affiliation(s)
- Kunming Zhou
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong 226019, China
| | - Yong Ni
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zhenghong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
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Shenkarev ZO, Chesnokov YM, Zaigraev MM, Chugunov AO, Kulbatskii DS, Kocharovskaya MV, Paramonov AS, Bychkov ML, Shulepko MA, Nolde DE, Kamyshinsky RA, Yablokov EO, Ivanov AS, Kirpichnikov MP, Lyukmanova EN. Membrane-mediated interaction of non-conventional snake three-finger toxins with nicotinic acetylcholine receptors. Commun Biol 2022; 5:1344. [PMID: 36477694 PMCID: PMC9729238 DOI: 10.1038/s42003-022-04308-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Nicotinic acetylcholine receptor of α7 type (α7-nAChR) presented in the nervous and immune systems and epithelium is a promising therapeutic target for cognitive disfunctions and cancer treatment. Weak toxin from Naja kaouthia venom (WTX) is a non-conventional three-finger neurotoxin, targeting α7-nAChR with weak affinity. There are no data on interaction mode of non-conventional neurotoxins with nAChRs. Using α-bungarotoxin (classical three-finger neurotoxin with high affinity to α7-nAChR), we showed applicability of cryo-EM to study complexes of α7-nAChR extracellular ligand-binding domain (α7-ECD) with toxins. Using cryo-EM structure of the α7-ECD/WTX complex, together with NMR data on membrane active site in the WTX molecule and mutagenesis data, we reconstruct the structure of α7-nAChR/WTX complex in the membrane environment. WTX interacts at the entrance to the orthosteric site located at the receptor intersubunit interface and simultaneously forms the contacts with the membrane surface. WTX interaction mode with α7-nAChR significantly differs from α-bungarotoxin's one, which does not contact the membrane. Our study reveals the important role of the membrane for interaction of non-conventional neurotoxins with the nicotinic receptors.
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Affiliation(s)
- Zakhar O. Shenkarev
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Yuri M. Chesnokov
- grid.18919.380000000406204151National Research Center “Kurchatov Institute”, Academic Kurchatov Sq. 1, Moscow, 123182 Russia ,grid.435159.f0000 0001 1941 7461Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333 Russia
| | - Maxim M. Zaigraev
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Anton O. Chugunov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia ,grid.410682.90000 0004 0578 2005National Research University Higher School of Economics, Myasnitskaya Str. 20, Moscow, 101000 Russia
| | - Dmitrii S. Kulbatskii
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Milita V. Kocharovskaya
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Alexander S. Paramonov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Maxim L. Bychkov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Mikhail A. Shulepko
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Dmitry E. Nolde
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.410682.90000 0004 0578 2005National Research University Higher School of Economics, Myasnitskaya Str. 20, Moscow, 101000 Russia
| | - Roman A. Kamyshinsky
- grid.18919.380000000406204151National Research Center “Kurchatov Institute”, Academic Kurchatov Sq. 1, Moscow, 123182 Russia ,grid.435159.f0000 0001 1941 7461Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333 Russia
| | - Evgeniy O. Yablokov
- grid.418846.70000 0000 8607 342XInstitute of Biomedical Chemistry, Pogodinskaya 10k8, Moscow, 119121 Russia
| | - Alexey S. Ivanov
- grid.418846.70000 0000 8607 342XInstitute of Biomedical Chemistry, Pogodinskaya 10k8, Moscow, 119121 Russia
| | - Mikhail P. Kirpichnikov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.14476.300000 0001 2342 9668Interdisciplinary Scientific and Educational School of Moscow University “Molecular Technologies of the Living Systems and Synthetic Biology”, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119234 Russia
| | - Ekaterina N. Lyukmanova
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia ,grid.14476.300000 0001 2342 9668Interdisciplinary Scientific and Educational School of Moscow University “Molecular Technologies of the Living Systems and Synthetic Biology”, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119234 Russia
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Nys M, Zarkadas E, Brams M, Mehregan A, Kambara K, Kool J, Casewell NR, Bertrand D, Baenziger JE, Nury H, Ulens C. The molecular mechanism of snake short-chain α-neurotoxin binding to muscle-type nicotinic acetylcholine receptors. Nat Commun 2022; 13:4543. [PMID: 35927270 PMCID: PMC9352773 DOI: 10.1038/s41467-022-32174-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/20/2022] [Indexed: 11/11/2022] Open
Abstract
Bites by elapid snakes (e.g. cobras) can result in life-threatening paralysis caused by venom neurotoxins blocking neuromuscular nicotinic acetylcholine receptors. Here, we determine the cryo-EM structure of the muscle-type Torpedo receptor in complex with ScNtx, a recombinant short-chain α-neurotoxin. ScNtx is pinched between loop C on the principal subunit and a unique hairpin in loop F on the complementary subunit, thereby blocking access to the neurotransmitter binding site. ScNtx adopts a binding mode that is tilted toward the complementary subunit, forming a wider network of interactions than those seen in the long-chain α-Bungarotoxin complex. Certain mutations in ScNtx at the toxin-receptor interface eliminate inhibition of neuronal α7 nAChRs, but not of human muscle-type receptors. These observations explain why ScNtx binds more tightly to muscle-type receptors than neuronal receptors. Together, these data offer a framework for understanding subtype-specific actions of short-chain α-neurotoxins and inspire strategies for design of new snake antivenoms.
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Affiliation(s)
- Mieke Nys
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, 3000, Leuven, Belgium.
| | - Eleftherios Zarkadas
- University Grenoble Alpes, CNRS, CEA, IBS, F-38000, Grenoble, France
- University Grenoble Alpes, CNRS, CEA, EMBL, ISBG, F-38000, Grenoble, France
| | - Marijke Brams
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, 3000, Leuven, Belgium
| | - Aujan Mehregan
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, 3000, Leuven, Belgium
| | | | - Jeroen Kool
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, 1081, HV, Amsterdam, Netherlands
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | | | - John E Baenziger
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Hugues Nury
- University Grenoble Alpes, CNRS, CEA, IBS, F-38000, Grenoble, France
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, 3000, Leuven, Belgium.
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10
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Zhang ZY, Lv Y, Wu W, Yan C, Tang CY, Peng C, Li JT. The structural and functional divergence of a neglected three-finger toxin subfamily in lethal elapids. Cell Rep 2022; 40:111079. [PMID: 35830808 DOI: 10.1016/j.celrep.2022.111079] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 05/04/2022] [Accepted: 06/20/2022] [Indexed: 11/24/2022] Open
Abstract
Bungarus multicinctus is a widely distributed and medically important elapid snake that produces lethal neurotoxic venom. To study and enhance existing antivenom, we explore the complete repertoire of its toxin genes based on de novo chromosome-level assembly and multi-tissue transcriptome data. Comparative genomic analyses suggest that the three-finger toxin family (3FTX) may evolve through the neofunctionalization of flanking LY6E. A long-neglected 3FTX subfamily (i.e., MKA-3FTX) is also investigated. Only one MKA-3FTX gene, which evolves a different protein conformation, is under positive selection and actively transcribed in the venom gland, functioning as a major toxin effector together with MKT-3FTX subfamily homologs. Furthermore, this lethal snake may acquire self-resistance to its β-bungarotoxin via amino acid replacements on fast-evolving KCNA2. This study provides valuable resources for further evolutionary and structure-function studies of snake toxins, which are fundamental for the development of effective antivenoms and drug candidates.
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Affiliation(s)
- Zhi-Yi Zhang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Yunyun Lv
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China; College of Life Science, Neijiang Normal University, Neijiang, Sichuan 641100, China
| | - Wei Wu
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China; University of Chinese Academy of Sciences, Beijing 101408, China
| | - Chaochao Yan
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Chen-Yang Tang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Changjun Peng
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China; University of Chinese Academy of Sciences, Beijing 101408, China
| | - Jia-Tang Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China; University of Chinese Academy of Sciences, Beijing 101408, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
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11
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Talukdar A, Maddhesiya P, Namsa ND, Doley R. Snake venom toxins targeting the central nervous system. TOXIN REV 2022. [DOI: 10.1080/15569543.2022.2084418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Amit Talukdar
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
| | - Priya Maddhesiya
- Cell Biology and Anatomy, Ludwig Maximilian University (LMU), Munich, Germany
| | - Nima Dondu Namsa
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
| | - Robin Doley
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
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12
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Trim CM, Byrne LJ, Trim SA. Utilisation of compounds from venoms in drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2021; 60:1-66. [PMID: 34147202 DOI: 10.1016/bs.pmch.2021.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Difficult drug targets are becoming the normal course of business in drug discovery, sometimes due to large interacting surfaces or only small differences in selectivity regions. For these, a different approach is merited: compounds lying somewhere between the small molecule and the large antibody in terms of many properties including stability, biodistribution and pharmacokinetics. Venoms have evolved over millions of years to be complex mixtures of stable molecules derived from other somatic molecules, the stability comes from the pressure to be ready for delivery at a moment's notice. Snakes, spiders, scorpions, jellyfish, wasps, fish and even mammals have evolved independent venom systems with complex mixtures in their chemical arsenal. These venom-derived molecules have been proven to be useful tools, such as for the development of antihypotensive angiotensin converting enzyme (ACE) inhibitors and have also made successful drugs such as Byetta® (Exenatide), Integrilin® (Eptifibatide) and Echistatin. Only a small percentage of the available chemical space from venoms has been investigated so far and this is growing. In a new era of biological therapeutics, venom peptides present opportunities for larger target engagement surface with greater stability than antibodies or human peptides. There are challenges for oral absorption and target engagement, but there are venom structures that overcome these and thus provide substrate for engineering novel molecules that combine all desired properties. Venom researchers are characterising new venoms, species, and functions all the time, these provide great substrate for solving the challenges presented by today's difficult targets.
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Affiliation(s)
- Carol M Trim
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
| | - Lee J Byrne
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
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13
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Bekbossynova A, Zharylgap A, Filchakova O. Venom-Derived Neurotoxins Targeting Nicotinic Acetylcholine Receptors. Molecules 2021; 26:molecules26113373. [PMID: 34204855 PMCID: PMC8199771 DOI: 10.3390/molecules26113373] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 01/02/2023] Open
Abstract
Acetylcholine was the first neurotransmitter described. The receptors targeted by acetylcholine are found within organisms spanning different phyla and position themselves as very attractive targets for predation, as well as for defense. Venoms of snakes within the Elapidae family, as well as those of marine snails within the Conus genus, are particularly rich in proteins and peptides that target nicotinic acetylcholine receptors (nAChRs). Such compounds are invaluable tools for research seeking to understand the structure and function of the cholinergic system. Proteins and peptides of venomous origin targeting nAChR demonstrate high affinity and good selectivity. This review aims at providing an overview of the toxins targeting nAChRs found within venoms of different animals, as well as their activities and the structural determinants important for receptor binding.
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Shah B, Sindhikara D, Borrelli K, Leffler AE. Water Thermodynamics of Peptide Toxin Binding Sites on Ion Channels. Toxins (Basel) 2020; 12:toxins12100652. [PMID: 33053750 PMCID: PMC7599640 DOI: 10.3390/toxins12100652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/21/2020] [Accepted: 10/09/2020] [Indexed: 12/20/2022] Open
Abstract
Peptide toxins isolated from venomous creatures, long prized as research tools due to their innate potency for ion channels, are emerging as drugs as well. However, it remains challenging to understand why peptide toxins bind with high potency to ion channels, to identify residues that are key for activity, and to improve their affinities via mutagenesis. We use WaterMap, a molecular dynamics simulation-based method, to gain computational insight into these three questions by calculating the locations and thermodynamic properties of water molecules in the peptide toxin binding sites of five ion channels. These include an acid-sensing ion channel, voltage-gated potassium channel, sodium channel in activated and deactivated states, transient-receptor potential channel, and a nicotinic receptor whose structures were recently determined by crystallography and cryo-electron microscopy (cryo-EM). All channels had water sites in the peptide toxin binding site, and an average of 75% of these sites were stable (low-energy), and 25% were unstable (medium or high energy). For the sodium channel, more unstable water sites were present in the deactivated state structure than the activated. Additionally, for each channel, unstable water sites coincided with the positions of peptide toxin residues that previous mutagenesis experiments had shown were important for activity. Finally, for the sodium channel in the deactivated state, unstable water sites were present in the peptide toxin binding pocket but did not overlap with the peptide toxin, suggesting that future experimental efforts could focus on targeting these sites to optimize potency.
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Affiliation(s)
- Binita Shah
- Schrödinger, Inc. 120 W. 45th St, New York, NY 10036, USA; (B.S.); (D.S.); (K.B.)
- PhD Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Dan Sindhikara
- Schrödinger, Inc. 120 W. 45th St, New York, NY 10036, USA; (B.S.); (D.S.); (K.B.)
| | - Ken Borrelli
- Schrödinger, Inc. 120 W. 45th St, New York, NY 10036, USA; (B.S.); (D.S.); (K.B.)
| | - Abba E. Leffler
- Schrödinger, Inc. 120 W. 45th St, New York, NY 10036, USA; (B.S.); (D.S.); (K.B.)
- Correspondence:
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15
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Gulsevin A, Meiler J. An Investigation of Three-Finger Toxin-nAChR Interactions through Rosetta Protein Docking. Toxins (Basel) 2020; 12:E598. [PMID: 32947868 PMCID: PMC7551183 DOI: 10.3390/toxins12090598] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/11/2020] [Accepted: 09/12/2020] [Indexed: 12/14/2022] Open
Abstract
Three-finger toxins (3FTX) are a group of peptides that affect multiple receptor types. One group of proteins affected by 3FTX are nicotinic acetylcholine receptors (nAChR). Structural information on how neurotoxins interact with nAChR is limited and is confined to a small group of neurotoxins. Therefore, in silico methods are valuable in understanding the interactions between 3FTX and different nAChR subtypes, but there are no established protocols to model 3FTX-nAChR interactions. We followed a homology modeling and protein docking protocol to address this issue and tested its success on three different systems. First, neurotoxin peptides co-crystallized with acetylcholine binding protein (AChBP) were re-docked to assess whether Rosetta protein-protein docking can reproduce the native poses. Second, experimental data on peptide binding to AChBP was used to test whether the docking protocol can qualitatively distinguish AChBP-binders from non-binders. Finally, we docked eight peptides with known α7 and muscle-type nAChR binding properties to test whether the protocol can explain the differential activities of the peptides at the two receptor subtypes. Overall, the docking protocol predicted the qualitative and some specific aspects of 3FTX binding to nAChR with reasonable success and shed light on unknown aspects of 3FTX binding to different receptor subtypes.
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Affiliation(s)
- Alican Gulsevin
- Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA;
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA;
- Institute for Drug Discovery, Leipzig University Medical School, 04103 Leipzig, Germany
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16
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Nirthanan S. Snake three-finger α-neurotoxins and nicotinic acetylcholine receptors: molecules, mechanisms and medicine. Biochem Pharmacol 2020; 181:114168. [PMID: 32710970 DOI: 10.1016/j.bcp.2020.114168] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 12/13/2022]
Abstract
Snake venom three-finger α-neurotoxins (α-3FNTx) act on postsynaptic nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction (NMJ) to produce skeletal muscle paralysis. The discovery of the archetypal α-bungarotoxin (α-BgTx), almost six decades ago, exponentially expanded our knowledge of membrane receptors and ion channels. This included the localisation, isolation and characterization of the first receptor (nAChR); and by extension, the pathophysiology and pharmacology of neuromuscular transmission and associated pathologies such as myasthenia gravis, as well as our understanding of the role of α-3FNTxs in snakebite envenomation leading to novel concepts of targeted treatment. Subsequent studies on a variety of animal venoms have yielded a plethora of novel toxins that have revolutionized molecular biomedicine and advanced drug discovery from bench to bedside. This review provides an overview of nAChRs and their subtypes, classification of α-3FNTxs and the challenges of typifying an increasing arsenal of structurally and functionally unique toxins, and the three-finger protein (3FP) fold in the context of the uPAR/Ly6/CD59/snake toxin superfamily. The pharmacology of snake α-3FNTxs including their mechanisms of neuromuscular blockade, variations in reversibility of nAChR interactions, specificity for nAChR subtypes or for distinct ligand-binding interfaces within a subtype and the role of α-3FNTxs in neurotoxic envenomation are also detailed. Lastly, a reconciliation of structure-function relationships between α-3FNTx and nAChRs, derived from historical mutational and biochemical studies and emerging atomic level structures of nAChR models in complex with α-3FNTxs is discussed.
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Affiliation(s)
- Selvanayagam Nirthanan
- School of Medical Science, Griffith Health Group, Griffith University, Gold Coast, Queensland, Australia.
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17
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Foo CS, Jobichen C, Hassan-Puttaswamy V, Dekan Z, Tae HS, Bertrand D, Adams DJ, Alewood PF, Sivaraman J, Nirthanan S, Kini RM. Fulditoxin, representing a new class of dimeric snake toxins, defines novel pharmacology at nicotinic ACh receptors. Br J Pharmacol 2020; 177:1822-1840. [PMID: 31877243 DOI: 10.1111/bph.14954] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Animal toxins have contributed significantly to our understanding of the neurobiology of receptors and ion channels. We studied the venom of the coral snake Micrurus fulvius fulvius and identified and characterized the structure and pharmacology of a new homodimeric neurotoxin, fulditoxin, that exhibited novel pharmacology at nicotinic ACh receptors (nAChRs). EXPERIMENTAL APPROACH Fulditoxin was isolated by chromatography, chemically synthesized, its structure determined by X-ray crystallography, and its pharmacological actions on nAChRs characterized by organ bath assays and two-electrode voltage clamp electrophysiology. KEY RESULTS Fulditoxin's distinct 1.95-Å quaternary structure revealed two short-chain three-finger α-neurotoxins (α-3FNTxs) non-covalently bound by hydrophobic interactions and an ability to bind metal and form tetrameric complexes, not reported previously for three-finger proteins. Although fulditoxin lacked all conserved amino acids canonically important for inhibiting nAChRs, it produced postsynaptic neuromuscular blockade of chick muscle at nanomolar concentrations, comparable to the prototypical α-bungarotoxin. This neuromuscular blockade was completely reversible, which is unusual for snake α-3FNTxs. Fulditoxin, therefore, interacts with nAChRs by utilizing a different pharmacophore. Unlike short-chain α-3FNTxs that bind only to muscle nAChRs, fulditoxin utilizes dimerization to expand its pharmacological targets to include human neuronal α4β2, α7, and α3β2 nAChRs which it blocked with IC50 values of 1.8, 7, and 12 μM respectively. CONCLUSIONS AND IMPLICATIONS Based on its distinct quaternary structure and unusual pharmacology, we named this new class of dimeric Micrurus neurotoxins represented by fulditoxin as Σ-neurotoxins, which offers greater insight into understanding the interactions between nAChRs and peptide antagonists.
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Affiliation(s)
- Chun Shin Foo
- Protein Science Laboratory, Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Varuna Hassan-Puttaswamy
- Protein Science Laboratory, Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Zoltan Dekan
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | | | - David J Adams
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - J Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Selvanayagam Nirthanan
- School of Medical Science, Griffith Health Group, Griffith University, Gold Coast, Queensland, Australia
| | - R Manjunatha Kini
- Protein Science Laboratory, Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
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Modahl CM, Brahma RK, Koh CY, Shioi N, Kini RM. Omics Technologies for Profiling Toxin Diversity and Evolution in Snake Venom: Impacts on the Discovery of Therapeutic and Diagnostic Agents. Annu Rev Anim Biosci 2019; 8:91-116. [PMID: 31702940 DOI: 10.1146/annurev-animal-021419-083626] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Snake venoms are primarily composed of proteins and peptides, and these toxins have developed high selectivity to their biological targets. This makes venoms interesting for exploration into protein evolution and structure-function relationships. A single venom protein superfamily can exhibit a variety of pharmacological effects; these variations in activity originate from differences in functional sites, domains, posttranslational modifications, and the formations of toxin complexes. In this review, we discuss examples of how the major venom protein superfamilies have diversified, as well as how newer technologies in the omics fields, such as genomics, transcriptomics, and proteomics, can be used to characterize both known and unknown toxins.Because toxins are bioactive molecules with a rich diversity of activities, they can be useful as therapeutic and diagnostic agents, and successful examples of toxin applications in these areas are also reviewed. With the current rapid pace of technology, snake venom research and its applications will only continue to expand.
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Affiliation(s)
- Cassandra M Modahl
- Protein Science Lab, Department of Biological Sciences, University of Singapore, Singapore 119077; , ,
| | - Rajeev Kungur Brahma
- Protein Science Lab, Department of Biological Sciences, University of Singapore, Singapore 119077; , ,
| | - Cho Yeow Koh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077;
| | - Narumi Shioi
- Protein Science Lab, Department of Biological Sciences, University of Singapore, Singapore 119077; , , .,Department of Chemistry, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan;
| | - R Manjunatha Kini
- Protein Science Lab, Department of Biological Sciences, University of Singapore, Singapore 119077; , ,
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19
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Effects of Snake Venom Pharmacopuncture on a Mouse model of Cerebral Infarction. JOURNAL OF ACUPUNCTURE RESEARCH 2019. [DOI: 10.13045/jar.2019.00073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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20
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Albulescu LO, Kazandjian T, Slagboom J, Bruyneel B, Ainsworth S, Alsolaiss J, Wagstaff SC, Whiteley G, Harrison RA, Ulens C, Kool J, Casewell NR. A Decoy-Receptor Approach Using Nicotinic Acetylcholine Receptor Mimics Reveals Their Potential as Novel Therapeutics Against Neurotoxic Snakebite. Front Pharmacol 2019; 10:848. [PMID: 31417406 PMCID: PMC6683245 DOI: 10.3389/fphar.2019.00848] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/02/2019] [Indexed: 12/24/2022] Open
Abstract
Snakebite is a neglected tropical disease that causes 138,000 deaths each year. Neurotoxic snake venoms contain small neurotoxins, including three-finger toxins (3FTxs), which can cause rapid paralysis in snakebite victims by blocking postsynaptic transmission via nicotinic acetylcholine receptors (nAChRs). These toxins are typically weakly immunogenic and thus are often not effectively targeted by current polyclonal antivenom therapies. We investigated whether nAChR mimics, also known as acetylcholine binding proteins (AChBPs), could effectively capture 3FTxs and therefore be developed as a novel class of snake-generic therapeutics for combatting neurotoxic envenoming. First, we identified the binding specificities of 3FTx from various medically important elapid snake venoms to nAChR using two recombinant nAChR mimics: the AChBP from Lymnaea stagnalis and a humanized neuronal α7 version (α7-AChBP). We next characterized these AChBP-bound and unbound fractions using SDS-PAGE and mass spectrometry. Interestingly, both mimics effectively captured long-chain 3FTxs from multiple snake species but largely failed to capture the highly related short-chain 3FTxs, suggesting a high level of binding specificity. We next investigated whether nAChR mimics could be used as snakebite therapeutics. We showed that while α7-AChBP alone did not protect against Naja haje (Egyptian cobra) venom lethality in vivo, it significantly prolonged survival times when coadministered with a nonprotective dose of antivenom. Thus, nAChR mimics are capable of neutralizing specific venom toxins and may be useful adjunct therapeutics for improving the safety and affordability of existing snakebite treatments by reducing therapeutic doses. Our findings justify exploring the future development of AChBPs as potential snakebite treatments.
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Affiliation(s)
- Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Taline Kazandjian
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Julien Slagboom
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Ben Bruyneel
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Stuart Ainsworth
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jaffer Alsolaiss
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Simon C Wagstaff
- Bioinformatics Unit, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Gareth Whiteley
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Robert A Harrison
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Jeroen Kool
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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21
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Ayvazyan NM, O'Leary VB, Dolly JO, Ovsepian SV. Neurobiology and therapeutic utility of neurotoxins targeting postsynaptic mechanisms of neuromuscular transmission. Drug Discov Today 2019; 24:1968-1984. [PMID: 31247153 DOI: 10.1016/j.drudis.2019.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 11/28/2022]
Abstract
The neuromuscular junction (NMJ) is the principal site for the translation of motor neurochemical signals to muscle activity. Therefore, the release and sensing machinery of acetylcholine (ACh) along with muscle contraction are two of the main targets of natural toxins and pathogens, causing paralysis. Given pharmacology and medical advances, the active ingredients of toxins that target postsynaptic mechanisms have become of major interest, showing promise as drug leads. Herein, we review key facets of prevalent toxins modulating the mechanisms of ACh sensing and generation of the postsynaptic response, with muscle contraction. We consider the correlation between their outstanding selectivity and potency plus effects on motor function, and discuss emerging data advocating their usage for the development of therapies alleviating neuromuscular dysfunction.
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Affiliation(s)
- Naira M Ayvazyan
- Orbeli Institute of Physiology, National Academy of Sciences of the Republic of Armenia, Yerevan, Armenia.
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland
| | - Saak V Ovsepian
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland; The National Institute of Mental Health, Topolová 748, Klecany, Czech Republic; Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic.
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22
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Prorocentrolide-A from Cultured Prorocentrum lima Dinoflagellates Collected in Japan Blocks Sub-Types of Nicotinic Acetylcholine Receptors. Toxins (Basel) 2018; 10:toxins10030097. [PMID: 29495549 PMCID: PMC5869385 DOI: 10.3390/toxins10030097] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/19/2018] [Accepted: 02/23/2018] [Indexed: 01/19/2023] Open
Abstract
Prorocentrolides are members of the cyclic imine phycotoxins family. Their chemical structure includes a 26-membered carbo-macrocycle and a 28-membered macrocyclic lactone arranged around a hexahydroisoquinoline that incorporates the characteristic cyclic imine group. Six prorocentrolides are already known. However, their mode of action remains undetermined. The aim of the present work was to explore whether prorocentrolide-A acts on nicotinic acetylcholine receptors (nAChRs), using competition-binding assays and electrophysiological techniques. Prorocentrolide-A displaced [125I]α-bungarotoxin binding to Torpedo membranes, expressing the muscle-type (α12β1γδ) nAChR, and in HEK-293 cells, expressing the chimeric chick neuronal α7-5HT3 nAChR. Functional studies revealed that prorocentrolide-A had no agonist action on nAChRs, but inhibited ACh-induced currents in Xenopus oocytes that had incorporated the muscle-type α12β1γδ nAChR to their membranes, or that expressed the human α7 nAChR, as revealed by voltage-clamp recordings. Molecular docking calculations showed the absence of the characteristic hydrogen bond between the iminium group of prorocentrolide-A and the backbone carbonyl group of Trp147 in the receptor, explaining its weaker affinity as compared to all other cyclic imine toxins. In conclusion, this is the first study to show that prorocentrolide-A acts on both muscle and neuronal nAChRs, but with higher affinity on the muscle-type nAChR.
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23
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Aird SD, da Silva NJ, Qiu L, Villar-Briones A, Saddi VA, Pires de Campos Telles M, Grau ML, Mikheyev AS. Coralsnake Venomics: Analyses of Venom Gland Transcriptomes and Proteomes of Six Brazilian Taxa. Toxins (Basel) 2017; 9:E187. [PMID: 28594382 PMCID: PMC5488037 DOI: 10.3390/toxins9060187] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 11/16/2022] Open
Abstract
Venom gland transcriptomes and proteomes of six Micrurus taxa (M. corallinus, M. lemniscatus carvalhoi, M. lemniscatus lemniscatus, M. paraensis, M. spixii spixii, and M. surinamensis) were investigated, providing the most comprehensive, quantitative data on Micrurus venom composition to date, and more than tripling the number of Micrurus venom protein sequences previously available. The six venomes differ dramatically. All are dominated by 2-6 toxin classes that account for 91-99% of the toxin transcripts. The M. s. spixii venome is compositionally the simplest. In it, three-finger toxins (3FTxs) and phospholipases A₂ (PLA₂s) comprise >99% of the toxin transcripts, which include only four additional toxin families at levels ≥0.1%. Micrurus l. lemniscatus venom is the most complex, with at least 17 toxin families. However, in each venome, multiple structural subclasses of 3FTXs and PLA₂s are present. These almost certainly differ in pharmacology as well. All venoms also contain phospholipase B and vascular endothelial growth factors. Minor components (0.1-2.0%) are found in all venoms except that of M. s. spixii. Other toxin families are present in all six venoms at trace levels (<0.005%). Minor and trace venom components differ in each venom. Numerous novel toxin chemistries include 3FTxs with previously unknown 8- and 10-cysteine arrangements, resulting in new 3D structures and target specificities. 9-cysteine toxins raise the possibility of covalent, homodimeric 3FTxs or heterodimeric toxins with unknown pharmacologies. Probable muscarinic sequences may be reptile-specific homologs that promote hypotension via vascular mAChRs. The first complete sequences are presented for 3FTxs putatively responsible for liberating glutamate from rat brain synaptosomes. Micrurus C-type lectin-like proteins may have 6-9 cysteine residues and may be monomers, or homo- or heterodimers of unknown pharmacology. Novel KSPIs, 3× longer than any seen previously, appear to have arisen in three species by gene duplication and fusion. Four species have transcripts homologous to the nociceptive toxin, (MitTx) α-subunit, but all six species had homologs to the β-subunit. The first non-neurotoxic, non-catalytic elapid phospholipase A₂s are reported. All are probably myonecrotic. Phylogenetic analysis indicates that the six taxa diverged 15-35 million years ago and that they split from their last common ancestor with Old World elapines nearly 55 million years ago. Given their early diversification, many cryptic micrurine taxa are anticipated.
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Affiliation(s)
- Steven D Aird
- Division of Faculty Affairs, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Nelson Jorge da Silva
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
| | - Lijun Qiu
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alejandro Villar-Briones
- Research Support Division, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Vera Aparecida Saddi
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Oncogenética e Radiobiologia da Associação de Combate ao Câncer em Goiás, Universidade Federal de Goiás, Rua 239 no. 52-Setor Universitário, Goiânia, Goiás 74065-070, Brazil.
| | - Mariana Pires de Campos Telles
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Genética & Biodiversidade, Universidade Federal de Goiás, Goiânia, Goiás 74690-900, Brazil.
| | - Miguel L Grau
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
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24
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Tan KY, Tan CH, Chanhome L, Tan NH. Comparative venom gland transcriptomics of Naja kaouthia (monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty. PeerJ 2017; 5:e3142. [PMID: 28392982 PMCID: PMC5384570 DOI: 10.7717/peerj.3142] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/03/2017] [Indexed: 11/20/2022] Open
Abstract
Background The monocled cobra (Naja kaouthia) is a medically important venomous snake in Southeast Asia. Its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. To investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes of N. kaouthia from Malaysia (NK-M) and Thailand (NK-T) applying next-generation sequencing (NGS) technology. Methods The transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T. Results and discussion The toxin transcripts showed high redundancy (41–82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin’s fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes from N. kaouthia which have not been reported hitherto; these include N. kaouthia-specific l-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.
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Affiliation(s)
- Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | | | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
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25
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Molgó J, Marchot P, Aráoz R, Benoit E, Iorga BI, Zakarian A, Taylor P, Bourne Y, Servent D. Cyclic imine toxins from dinoflagellates: a growing family of potent antagonists of the nicotinic acetylcholine receptors. J Neurochem 2017; 142 Suppl 2:41-51. [PMID: 28326551 DOI: 10.1111/jnc.13995] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 12/24/2022]
Abstract
We present an overview of the toxicological profile of the fast-acting, lipophilic macrocyclic imine toxins, an emerging family of organic compounds associated with algal blooms, shellfish contamination and neurotoxicity. Worldwide, shellfish contamination incidents are expanding; therefore, the significance of these toxins for the shellfish food industry deserves further study. Emphasis is directed to the dinoflagellate species involved in their production, their chemical structures, and their specific mode of interaction with their principal natural molecular targets, the nicotinic acetylcholine receptors, or with the soluble acetylcholine-binding protein, used as a surrogate receptor model. The dinoflagellates Karenia selliformis and Alexandrium ostenfeldii / A. peruvianum have been implicated in the biosynthesis of gymnodimines and spirolides, while Vulcanodinium rugosum is the producer of pinnatoxins and portimine. The cyclic imine toxins are characterized by a macrocyclic skeleton comprising 14-27 carbon atoms, flanked by two conserved moieties, the cyclic imine and the spiroketal ring system. These phycotoxins generally display high affinity and broad specificity for the muscle type and neuronal nicotinic acetylcholine receptors, a feature consistent with their binding site at the receptor subunit interfaces, composed of residues highly conserved among all nAChRs, and explaining the diverse toxicity among animal species. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Jordi Molgó
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Pascale Marchot
- Aix-Marseille Université / Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Marseille, France
| | - Rómulo Aráoz
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Evelyne Benoit
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Bogdan I Iorga
- Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles, UPR 2301, Labex LERMIT, Gif-sur-Yvette, France
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California, USA
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yves Bourne
- Aix-Marseille Université / Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Marseille, France
| | - Denis Servent
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France
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26
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de la Rosa G, Pastor N, Alagón A, Corzo G. Synthetic peptide antigens derived from long-chain alpha-neurotoxins: Immunogenicity effect against elapid venoms. Peptides 2017; 88:80-86. [PMID: 28010961 DOI: 10.1016/j.peptides.2016.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 10/20/2022]
Abstract
Three-finger toxins (3FTXs), especially α-neurotoxins, are the most poorly neutralized elapid snake toxins by current antivenoms. In this work, the conserved structural similarity and motif arrangements of long-chain α-neurotoxins led us to design peptides with consensus sequences. Eight long-chain α-neurotoxins (also known as Type II) were used to generate a consensus sequence from which two peptides were chemically synthesized, LCP1 and LCP2. Rabbit sera raised against them were able to generate partially-neutralizing antibodies, which delayed mice mortality in neutralization assays against Naja haje, Dendrospis polylepis and Ophiophagus hannah venoms.
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Affiliation(s)
- Guillermo de la Rosa
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca Morelos 61500, Mexico
| | - Nina Pastor
- Centro de Investigación en Dinámica Celular, IICBA, UAEM, Av. Universidad 1001 Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico
| | - Alejandro Alagón
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca Morelos 61500, Mexico
| | - Gerardo Corzo
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca Morelos 61500, Mexico.
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27
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Couesnon A, Aráoz R, Iorga BI, Benoit E, Reynaud M, Servent D, Molgó J. The Dinoflagellate Toxin 20-Methyl Spirolide-G Potently Blocks Skeletal Muscle and Neuronal Nicotinic Acetylcholine Receptors. Toxins (Basel) 2016; 8:E249. [PMID: 27563924 PMCID: PMC5037475 DOI: 10.3390/toxins8090249] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/06/2016] [Accepted: 08/12/2016] [Indexed: 11/16/2022] Open
Abstract
The cyclic imine toxin 20-methyl spirolide G (20-meSPX-G), produced by the toxigenic dinoflagellate Alexandrium ostenfeldii/Alexandrium peruvianum, has been previously reported to contaminate shellfish in various European coastal locations, as revealed by mouse toxicity bioassay. The aim of the present study was to determine its toxicological profile and its molecular target selectivity. 20-meSPX-G blocked nerve-evoked isometric contractions in isolated mouse neuromuscular preparations, while it had no action on contractions elicited by direct electrical stimulation, and reduced reversibly nerve-evoked compound muscle action potential amplitudes in anesthetized mice. Voltage-clamp recordings in Xenopus oocytes revealed that 20-meSPX-G potently inhibited currents evoked by ACh on Torpedo muscle-type and human α7 nicotinic acetylcholine receptors (nAChR), whereas lower potency was observed in human α4β2 nAChR. Competition-binding assays showed that 20-meSPX-G fully displaced [³H]epibatidine binding to HEK-293 cells expressing the human α3β2 (Ki = 0.040 nM), whereas a 90-fold lower affinity was detected in human α4β2 nAChR. The spirolide displaced [(125)I]α-bungarotoxin binding to Torpedo membranes (Ki = 0.028 nM) and in HEK-293 cells expressing chick chimeric α7-5HT₃ nAChR (Ki = 0.11 nM). In conclusion, this is the first study to demonstrate that 20-meSPX-G is a potent antagonist of nAChRs, and its subtype selectivity is discussed on the basis of molecular docking models.
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MESH Headings
- Action Potentials
- Animals
- Binding Sites
- Binding, Competitive
- Bridged Bicyclo Compounds, Heterocyclic/metabolism
- Chickens
- Cholinergic Fibers/drug effects
- Cholinergic Fibers/metabolism
- Dose-Response Relationship, Drug
- Electric Stimulation
- Female
- HEK293 Cells
- Humans
- In Vitro Techniques
- Isometric Contraction/drug effects
- Mice
- Molecular Docking Simulation
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/innervation
- Muscle, Skeletal/metabolism
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/metabolism
- Nicotinic Antagonists/chemistry
- Nicotinic Antagonists/metabolism
- Nicotinic Antagonists/toxicity
- Protein Binding
- Protein Conformation
- Pyridines/metabolism
- Receptors, Nicotinic/chemistry
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/genetics
- Receptors, Nicotinic/metabolism
- Spiro Compounds/chemistry
- Spiro Compounds/metabolism
- Spiro Compounds/toxicity
- Structure-Activity Relationship
- Torpedo
- Transfection
- Xenopus laevis
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Affiliation(s)
- Aurélie Couesnon
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
| | - Rómulo Aráoz
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Bogdan I Iorga
- Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles, UPR 2301, Labex LERMIT, F-91198 Gif-sur-Yvette, France.
| | - Evelyne Benoit
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Morgane Reynaud
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Denis Servent
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Jordi Molgó
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
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Tan KY, Tan CH, Sim SM, Fung SY, Tan NH. Geographical venom variations of the Southeast Asian monocled cobra (Naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization. Comp Biochem Physiol C Toxicol Pharmacol 2016; 185-186:77-86. [PMID: 26972756 DOI: 10.1016/j.cbpc.2016.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/06/2016] [Accepted: 03/09/2016] [Indexed: 11/30/2022]
Abstract
The Southeast Asian monocled cobras (Naja kaouthia) exhibit geographical variations in their venom proteomes, especially on the composition of neurotoxins. This study compared the neuromuscular depressant activity of the venoms of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V), and the neutralization of neurotoxicity by a monospecific antivenom. On chick biventer cervicis nerve-muscle preparation, all venoms abolished the indirect twitches, with NK-T venom being the most potent (shortest t90, time to 90% twitch inhibition), followed by NK-V and NK-M. Acetylcholine and carbachol failed to reverse the blockade, indicating irreversible/pseudo-irreversible post-synaptic neuromuscular blockade. KCl restored the twitches variably (NK-M preparation being the least responsive), consistent with different degree of muscle damage. The findings support that NK-T venom has the most abundant curarimimetic alpha-neurotoxins, while NK-M venom contains more tissue-damaging cytotoxins. Pre-incubation of tissue with N. kaouthia monovalent antivenom (NKMAV) prevented venom-induced twitch depression, with the NK-T preparation needing the largest antivenom dose. NKMAV added after the onset of neuromuscular depression could only halt the inhibitory progression but failed to restore full contraction. The findings highlight the urgency of early antivenom administration to sequester as much circulating neurotoxins as possible, thereby hastening toxin elimination from the circulation. In envenomed mice, NKMAV administered upon the first neurological sign neutralized the neurotoxic effect, with the slowest full recovery noticed in the NK-T group. This is consistent with the high abundance of neurotoxins in the NK-T venom, implying that a larger amount or repeated dosing of NKMAV may be required in NK-T envenomation.
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Affiliation(s)
- Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Si Mui Sim
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Shin Yee Fung
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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29
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Nicotinic receptor involvement in regulation of functions of mouse neutrophils from inflammatory site. Immunobiology 2016; 221:761-72. [DOI: 10.1016/j.imbio.2016.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/30/2016] [Indexed: 01/08/2023]
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30
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Barnwal B, Jobichen C, Girish VM, Foo CS, Sivaraman J, Kini RM. Ringhalexin from Hemachatus haemachatus: A novel inhibitor of extrinsic tenase complex. Sci Rep 2016; 6:25935. [PMID: 27173146 PMCID: PMC4865804 DOI: 10.1038/srep25935] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/26/2016] [Indexed: 12/15/2022] Open
Abstract
Anticoagulant therapy is used for the prevention and treatment of thromboembolic disorders. Blood coagulation is initiated by the interaction of factor VIIa (FVIIa) with membrane-bound tissue factor (TF) to form the extrinsic tenase complex which activates FX to FXa. Thus, it is an important target for the development of novel anticoagulants. Here, we report the isolation and characterization of a novel anticoagulant ringhalexin from the venom of Hemachatus haemachatus (African Ringhals Cobra). Amino acid sequence of the protein indicates that it belongs to the three-finger toxin family and exhibits 94% identity to an uncharacterized Neurotoxin-like protein NTL2 from Naja atra. Ringhalexin inhibited FX activation by extrinsic tenase complex with an IC50 of 123.8 ± 9.54 nM. It is a mixed-type inhibitor with the kinetic constants, Ki and Ki' of 84.25 ± 3.53 nM and 152.5 ± 11.32 nM, respectively. Ringhalexin also exhibits a weak, irreversible neurotoxicity on chick biventer cervicis muscle preparations. Subsequently, the three-dimensional structure of ringhalexin was determined at 2.95 Å resolution. This study for the first time reports the structure of an anticoagulant three-finger toxin. Thus, ringhalexin is a potent inhibitor of the FX activation by extrinsic tenase complex and a weak, irreversible neurotoxin.
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Affiliation(s)
- Bhaskar Barnwal
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260, Singapore
| | | | - Chun Shin Foo
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260, Singapore
| | - J. Sivaraman
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260, Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260, Singapore
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31
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Marine Natural Products from New Caledonia--A Review. Mar Drugs 2016; 14:md14030058. [PMID: 26999165 PMCID: PMC4820312 DOI: 10.3390/md14030058] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 01/17/2023] Open
Abstract
Marine micro- and macroorganisms are well known to produce metabolites with high biotechnological potential. Nearly 40 years of systematic prospecting all around the New Caledonia archipelago and several successive research programs have uncovered new chemical leads from benthic and planktonic organisms. After species identification, biological and/or pharmaceutical analyses are performed on marine organisms to assess their bioactivities. A total of 3582 genera, 1107 families and 9372 species have been surveyed and more than 350 novel molecular structures have been identified. Along with their bioactivities that hold promise for therapeutic applications, most of these molecules are also potentially useful for cosmetics and food biotechnology. This review highlights the tremendous marine diversity in New Caledonia, and offers an outline of the vast possibilities for natural products, especially in the interest of pursuing collaborative fundamental research programs and developing local biotechnology programs.
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32
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Venomics of the Australian eastern brown snake ( Pseudonaja textilis ): Detection of new venom proteins and splicing variants. Toxicon 2015; 107:252-65. [DOI: 10.1016/j.toxicon.2015.06.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 01/28/2023]
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33
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Utkin YN, Kasheverov IE, Kudryavtsev DS, Andreeva TV, Starkov VG, Ziganshin RH, Kuznetsov DV, Anh HN, Thao NTT, Khoa NC, Tsetlin VI. Nonconventional three-finger toxin BMLCL from krait Bungarus multicinctus venom with high affinity interacts with nicotinic acetylcholine receptors. DOKL BIOCHEM BIOPHYS 2015; 464:294-7. [PMID: 26518551 DOI: 10.1134/s1607672915050099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Indexed: 12/16/2022]
Abstract
Nonconventional three-finger toxin BMLCL was isolated from B. multicinctus venom, and its interaction with different subtypes of nicotinic acetylcholine receptor (nAChR) was studied. It was found that BMLCL is able to interact with high efficiency with both α7 and muscle type nAChRs.
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Affiliation(s)
- Yu N Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia. .,The National University of Science and Technology MISiS, Moscow, Russia.
| | - I E Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.,Syneuro Ltd., Moscow, Russia
| | - D S Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.,Syneuro Ltd., Moscow, Russia
| | - T V Andreeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - V G Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - R H Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - D V Kuznetsov
- The National University of Science and Technology MISiS, Moscow, Russia
| | - Hoang Ngoc Anh
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Thanh Thao
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
| | - Nguyen Cuu Khoa
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
| | - V I Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
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A comparative study of venomics of Naja naja from India and Sri Lanka, clinical manifestations and antivenomics of an Indian polyspecific antivenom. J Proteomics 2015; 132:131-43. [PMID: 26506536 DOI: 10.1016/j.jprot.2015.10.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/24/2015] [Accepted: 10/08/2015] [Indexed: 11/22/2022]
Abstract
Naja naja (Indian cobra) from Sri Lanka and India is the WHO Category 1 medically important snakes in both countries. Some antivenom produced against Indian N. naja (NNi) were less effective against Sri Lankan N. naja (NNsl). Proteomes of NNi and NNsl venoms were studied by RP-HPLC, SDS-PAGE and LC/MS/MS. Six protein families were identified in both venoms with the most abundant were the 3 finger toxins (3FTs) where cytotoxins (CTX) subtype predominated, followed by phospholipase A2, cysteine-rich venom protein, snake venom metalloproteases, venom growth factors, and protease inhibitors. Qualitative and quantitative differences in the venomics profiles were observed. Some proteins were isolated from either NNi or NNsl venom. Postsynaptic neurotoxins (NTX) were identified for the first time in NNsl venom. Thus, there are geographic intra-specific variations of venom composition of the two N. naja. The relative abundance of CTX and NTX explained well the clinical manifestations of these venoms. Antivenomics study of an Indian antivenom (Vins) showed the antibodies effectively bound all venom toxins from both snakes but more avidly to the Indian venom proteins. The lower antibody affinity towards the 'heterologous' venom was the likely cause of poor efficacy of the Indian antivenom used to treat NNsl envenoming.
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Aráoz R, Ouanounou G, Iorga BI, Goudet A, Alili D, Amar M, Benoit E, Molgó J, Servent D. The Neurotoxic Effect of 13,19-Didesmethyl and 13-Desmethyl Spirolide C Phycotoxins Is Mainly Mediated by Nicotinic Rather Than Muscarinic Acetylcholine Receptors. Toxicol Sci 2015; 147:156-67. [DOI: 10.1093/toxsci/kfv119] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Bourne Y, Sulzenbacher G, Radić Z, Aráoz R, Reynaud M, Benoit E, Zakarian A, Servent D, Molgó J, Taylor P, Marchot P. Marine Macrocyclic Imines, Pinnatoxins A and G: Structural Determinants and Functional Properties to Distinguish Neuronal α7 from Muscle α1(2)βγδ nAChRs. Structure 2015; 23:1106-15. [PMID: 26004441 DOI: 10.1016/j.str.2015.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 10/23/2022]
Abstract
Pinnatoxins are macrocyclic imine phycotoxins associated with algal blooms and shellfish toxicity. Functional analysis of pinnatoxin A and pinnatoxin G by binding and voltage-clamp electrophysiology on membrane-embedded neuronal α7, α4β2, α3β2, and muscle-type α12βγδ nicotinic acetylcholine receptors (nAChRs) reveals high-affinity binding and potent antagonism for the α7 and α12βγδ subtypes. The toxins also bind to the nAChR surrogate, acetylcholine-binding protein (AChBP), with low Kd values reflecting slow dissociation. Crystal structures of pinnatoxin-AChBP complexes (1.9-2.2 Å resolution) show the multiple anchoring points of the hydrophobic portion, the cyclic imine, and the substituted bis-spiroketal and cyclohexene ring systems of the pinnatoxins that dictate tight binding between the opposing loops C and F at the receptor subunit interface, as observed for the 13-desmethyl-spirolide C and gymnodimine A congeners. Uniquely, however, the bulky bridged EF-ketal ring specific to the pinnatoxins extends radially from the interfacial-binding pocket to interact with the sequence-variable loop F and govern nAChR subtype selectivity and central neurotoxicity.
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Affiliation(s)
- Yves Bourne
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
| | - Gerlind Sulzenbacher
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France
| | - Zoran Radić
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Rómulo Aráoz
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Morgane Reynaud
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Evelyne Benoit
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California Santa Barbara, CA 93106-9510, USA
| | - Denis Servent
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Jordi Molgó
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Pascale Marchot
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
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37
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Reeks TA, Fry BG, Alewood PF. Privileged frameworks from snake venom. Cell Mol Life Sci 2015; 72:1939-58. [PMID: 25693678 PMCID: PMC11113608 DOI: 10.1007/s00018-015-1844-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 11/25/2022]
Abstract
Venom as a form of chemical prey capture is a key innovation that has underpinned the explosive radiation of the advanced snakes (Caenophidia). Small venom proteins are often rich in disulfide bonds thus facilitating stable molecular scaffolds that present key functional residues on the protein surface. New toxin types are initially developed through the venom gland over-expression of normal body proteins, their subsequent gene duplication and diversification that leads to neofunctionalisation as random mutations modify their structure and function. This process has led to preferentially selected (privileged) cysteine-rich scaffolds that enable the snake to build arrays of toxins many of which may lead to therapeutic products and research tools. This review focuses on cysteine-rich small proteins and peptides found in snake venoms spanning natriuretic peptides to phospholipase enzymes, while highlighting their three-dimensional structures and biological functions as well as their potential as therapeutic agents or research tools.
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Affiliation(s)
- T. A. Reeks
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - B. G. Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072 Australia
| | - P. F. Alewood
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
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38
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Tan KY, Tan CH, Fung SY, Tan NH. Venomics, lethality and neutralization of Naja kaouthia (monocled cobra) venoms from three different geographical regions of Southeast Asia. J Proteomics 2015; 120:105-25. [PMID: 25748141 DOI: 10.1016/j.jprot.2015.02.012] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/18/2015] [Accepted: 02/24/2015] [Indexed: 01/15/2023]
Abstract
UNLABELLED Previous studies showed that venoms of the monocled cobra, Naja kaouthia from Thailand and Malaysia are substantially different in their median lethal doses. The intraspecific venom variations of N. kaouthia, however, have not been fully elucidated. Here we investigated the venom proteomes of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V) through reverse-phase HPLC, SDS-PAGE and tandem mass spectrometry. The venom proteins comprise 13 toxin families, with three-finger toxins being the most abundant (63-77%) and the most varied (11-18 isoforms) among the three populations. NK-T has the highest content of neurotoxins (50%, predominantly long neurotoxins), followed by NK-V (29%, predominantly weak neurotoxins and some short neurotoxins), while NK-M has the least (18%, some weak neurotoxins but less short and long neurotoxins). On the other hand, cytotoxins constitute the main bulk of toxins in NK-M and NK-V venoms (up to 45% each), but less in NK-T venom (27%). The three venoms show different lethal potencies that generally reflect the proteomic findings. Despite the proteomic variations, the use of Thai monovalent and Neuro polyvalent antivenoms for N. kaouthia envenomation in the three regions is appropriate as the different venoms were neutralized by the antivenoms albeit at different degrees of effectiveness. BIOLOGICAL SIGNIFICANCE Biogeographical variations were observed in the venom proteome of monocled cobra (Naja kaouthia) from Malaysia, Thailand and Vietnam. The Thai N. kaouthia venom is particularly rich in long neurotoxins, while the Malaysian and Vietnamese specimens were predominated with cytotoxins. The differentially expressed toxin profile accounts for the discrepancy in the lethal dose of the venom from different populations. Commercially available Thai antivenoms (monovalent and polyvalent) were able to neutralize the three venoms at different effective doses, hence supporting their uses in the three regions. While dose adjustment according to geographical region seems possible, changes to standard recommended dosage should only be made if further study validates that the monocled cobras within a population do not exhibit remarkable inter-individual venom variation.
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Affiliation(s)
- Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; University of Malaya Centre for Proteomics Research (UMPCR), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Shin Yee Fung
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; University of Malaya Centre for Proteomics Research (UMPCR), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; University of Malaya Centre for Proteomics Research (UMPCR), University of Malaya, 50603 Kuala Lumpur, Malaysia
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39
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Rusmili MRA, Tee TY, Mustafa MR, Othman I, Hodgson WC. Isolation and characterization of α-elapitoxin-Bf1b, a postsynaptic neurotoxin from Malaysian Bungarus fasciatus venom. Biochem Pharmacol 2014; 88:229-36. [DOI: 10.1016/j.bcp.2014.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/03/2014] [Accepted: 01/07/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Muhamad Rusdi Ahmad Rusmili
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, 3168 Clayton, Victoria, Australia; Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, 46150 Bandar Sunway, Malaysia
| | - Ting Yee Tee
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, 46150 Bandar Sunway, Malaysia
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 59100 Kuala Lumpur, Malaysia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, 46150 Bandar Sunway, Malaysia
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, 3168 Clayton, Victoria, Australia.
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40
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Inter-residue coupling contributes to high-affinity subtype-selective binding of α-bungarotoxin to nicotinic receptors. Biochem J 2013; 454:311-21. [PMID: 23802200 DOI: 10.1042/bj20130638] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The crystal structure of a pentameric α7 ligand-binding domain chimaera with bound α-btx (α-bungarotoxin) showed that of the five conserved aromatic residues in α7, only Tyr¹⁸⁴ in loop C of the ligand-binding site was required for high-affinity binding. To determine whether the contribution of Tyr¹⁸⁴ depends on local residues, we generated mutations in an α7/5HT(3A) (5-hydroxytryptamine type 3A) receptor chimaera, individually and in pairs, and measured ¹²⁵I-labelled α-btx binding. The results show that mutations of individual residues near Tyr¹⁸⁴ do not affect α-btx affinity, but pairwise mutations decrease affinity in an energetically coupled manner. Kinetic measurements show that the affinity decreases arise through increases in the α-btx dissociation rate with little change in the association rate. Replacing loop C in α7 with loop C from the α-btx-insensitive α2 or α3 subunits abolishes high-affinity α-btx binding, but preserves acetylcholine-elicited single channel currents. However, in both the α2 and α3 construct, mutating either residue that flanks Tyr¹⁸⁴ to its α7 counterpart restores high-affinity α-btx binding. Analogously, in α7, mutating both residues that flank Tyr¹⁸⁴ to the α2 or α3 counterparts abolishes high-affinity α-btx binding. Thus interaction between Tyr¹⁸⁴ and local residues contributes to high-affinity subtype-selective α-btx binding.
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Unfolding stabilities of two paralogous proteins from Naja naja naja (Indian cobra) as probed by molecular dynamics simulations. Toxicon 2013; 72:11-22. [DOI: 10.1016/j.toxicon.2013.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 05/20/2013] [Accepted: 05/30/2013] [Indexed: 11/21/2022]
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Heyborne WH, Mackessy SP. Identification and characterization of a taxon-specific three-finger toxin from the venom of the Green Vinesnake (Oxybelis fulgidus; family Colubridae). Biochimie 2013; 95:1923-32. [PMID: 23851011 DOI: 10.1016/j.biochi.2013.06.025] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 06/27/2013] [Indexed: 11/17/2022]
Abstract
Snake venoms contain a variety of protein and peptide toxins, and the three-finger toxins (3FTxs) are among the best characterized family of venom proteins. The compact nature and highly conserved molecular fold of 3FTxs, together with their abundance in many venoms, has contributed to their utility in structure-function studies. Although many target the nicotinic acetylcholine receptor of vertebrate skeletal muscle, often binding with nanomolar Kds, several non-conventional 3FTxs show pronounced taxon-specific neurotoxic effects. Here we describe the purification and characterization of fulgimotoxin, a monomeric 3FTx from the venom of Oxybelis fulgidus, a neotropical rear-fanged snake. Fulgimotoxin retains the canonical 5 disulfides of the non-conventional 3FTxs and is highly neurotoxic to lizards; however, mice are unaffected, demonstrating that this toxin is taxon-specific in its effects. Analysis of structural features of fulgimotoxin and other colubrid venom 3FTxs indicate the presence of a "colubrid toxin motif" (CYTLY) and a second conserved segment (WAVK) found in Boiga and Oxybelis taxon-specific 3FTxs, both in loop II. Because specific residues in loop II conventional α-neurotoxic 3FTxs are intimately associated with receptor binding, we hypothesize that this loop, with its highly conserved substitutions, confers taxon-specific neurotoxicity. These findings underscore the importance of rear-fanged snake venoms for understanding the evolution of toxin molecules and demonstrate that even among well-characterized toxin families, novel structural and functional motifs may be found.
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Affiliation(s)
- William H Heyborne
- School of Biological Sciences, University of Northern Colorado, 501 20th St., CB 92, Greeley, CO 80639-0017, USA
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Functional proteomic approach to discover geographic variations of king cobra venoms from Southeast Asia and China. J Proteomics 2013; 89:141-53. [PMID: 23796489 DOI: 10.1016/j.jprot.2013.06.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/10/2013] [Accepted: 06/13/2013] [Indexed: 11/21/2022]
Abstract
UNLABELLED This study deciphers the geographic variations of king cobra (Ophiophagus hannah) venom using functional proteomics. Pooled samples of king cobra venom (abbreviated as Ohv) were obtained from Indonesia, Malaysia, Thailand, and two provinces of China, namely Guangxi and Hainan. Using two animal models to test and compare the lethal effects, we found that the Chinese Ohvs were more fatal to mice, while the Southeast Asian Ohvs were more fatal to lizards (Eutropis multifasciata). Various phospholipases A2 (PLA2s), three-finger toxins (3FTxs) and Kunitz-type inhibitors were purified from these Ohvs and compared. Besides the two Chinese Ohv PLA2s with known sequences, eight novel PLA2s were identified from the five Ohv samples and their antiplatelet activities were compared. While two 3FTxs (namely oh-55 and oh-27) were common in all the Ohvs, different sets of 3FTx markers were present in the Chinese and Southeast Asian Ohvs. All the Ohvs contain the Kunitz inhibitor, OH-TCI, while only the Chinese Ohvs contain the inhibitor variant, Oh11-1. Relative to the Chinese Ohvs which contained more phospholipases, the Southeast Asian Ohvs had higher metalloproteinase, acetylcholine esterase, and alkaline phosphatase activities. BIOLOGICAL SIGNIFICANCE Remarkable variations in five king cobra geographic samples reveal fast evolution and dynamic translational regulation of the venom which probably adapted to different prey ecology as testified by the lethal tests on mice and lizards. Our results predict possible variations of the king cobra envenoming to human and the importance of using local antivenin for snakebite treatment.
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Bailly-Chouriberry L, Cormant F, Garcia P, Kind A, Popot MA, Bonnaire Y. Identification of α-Cobratoxin in Equine Plasma by LC-MS/MS for Doping Control. Anal Chem 2013; 85:5219-25. [DOI: 10.1021/ac4006342] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
| | - Florence Cormant
- Laboratoire des Courses Hippiques (LCH), 15 rue de Paradis, 91370 Verrières
le Buisson, France
| | - Patrice Garcia
- Laboratoire des Courses Hippiques (LCH), 15 rue de Paradis, 91370 Verrières
le Buisson, France
| | - Albert Kind
- CYCADS
Laboratory, Iowa State College of Veterinary Medicine, 1600 S 16th Street, Ames, Iowa 50011, United States
| | - Marie-Agnès Popot
- Laboratoire des Courses Hippiques (LCH), 15 rue de Paradis, 91370 Verrières
le Buisson, France
| | - Yves Bonnaire
- Laboratoire des Courses Hippiques (LCH), 15 rue de Paradis, 91370 Verrières
le Buisson, France
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Quinton L, Servent D, Girard E, Molgó J, Le Caer JP, Malosse C, Haidar EA, Lecoq A, Gilles N, Chamot-Rooke J. Identification and functional characterization of a novel α-conotoxin (EIIA) from Conus ermineus. Anal Bioanal Chem 2013; 405:5341-51. [PMID: 23584713 DOI: 10.1007/s00216-013-6926-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/14/2013] [Accepted: 03/18/2013] [Indexed: 01/22/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are one of the most important families in the ligand-gated ion channel superfamily due to their involvement in primordial brain functions and in several neurodegenerative pathologies. The discovery of new ligands which can bind with high affinity and selectivity to nAChR subtypes is of prime interest in order to study these receptors and to potentially discover new drugs for treating various pathologies. Predatory cone snails of the genus Conus hunt their prey using venoms containing a large number of small, highly structured peptides called conotoxins. Conotoxins are classified in different structural families and target a large panel of receptors and ion channels. Interestingly, nAChRs represent the only subgroup for which Conus has developed seven distinct families of conotoxins. Conus venoms have thus received much attention as they could represent a potential source of selective ligands of nAChR subtypes. We describe the mass spectrometric-based approaches which led to the discovery of a novel α-conotoxin targeting muscular nAChR from the venom of Conus ermineus. The presence of several posttranslational modifications complicated the N-terminal sequencing. To discriminate between the different possible sequences, analogs with variable N-terminus were synthesized and fragmented by MS/MS. Understanding the fragmentation pathways in the low m/z range appeared crucial to determine the right sequence. The biological activity of this novel α-conotoxin (α-EIIA) that belongs to the unusual α4/4 subfamily was determined by binding experiments. The results revealed not only its selectivity for the muscular nAChR, but also a clear discrimination between the two binding sites described for this receptor.
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Affiliation(s)
- Loïc Quinton
- Laboratoire des Mécanismes Réactionnels, Département de Chimie, Ecole Polytechnique, CNRS UMR7651, 91128 Palaiseau Cedex, France
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Barber CM, Isbister GK, Hodgson WC. Alpha neurotoxins. Toxicon 2013; 66:47-58. [PMID: 23416229 DOI: 10.1016/j.toxicon.2013.01.019] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/29/2013] [Indexed: 10/27/2022]
Abstract
α-Neurotoxins have been isolated from hydrophid, elapid and, more recently, colubrid snake venoms. Also referred to as postsynaptic neurotoxins or 'curare mimetic' neurotoxins, they play an important role in the capture and/or killing of prey by binding to the nicotinic acetylcholine receptor on the skeletal muscle disrupting neurotransmission. They are also thought to cause respiratory paralysis in envenomed humans. This review will discuss the historical background into the discovery, isolation, structure and mechanism of action of the α-neurotoxins, including targets and cellular outcomes, and then will examine the potential uses of α-neurotoxins as pharmacological tools and/or as drug leads.
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Affiliation(s)
- Carmel M Barber
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
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Girish VM, Kumar S, Joseph L, Jobichen C, Kini RM, Sivaraman J. Identification and structural characterization of a new three-finger toxin hemachatoxin from Hemachatus haemachatus venom. PLoS One 2012; 7:e48112. [PMID: 23144733 PMCID: PMC3483290 DOI: 10.1371/journal.pone.0048112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 09/19/2012] [Indexed: 01/26/2023] Open
Abstract
Snake venoms are rich sources of biologically active proteins and polypeptides. Three-finger toxins are non-enzymatic proteins present in elapid (cobras, kraits, mambas and sea snakes) and colubrid venoms. These proteins contain four conserved disulfide bonds in the core to maintain the three-finger folds. Although all three-finger toxins have similar fold, their biological activities are different. A new three-finger toxin (hemachatoxin) was isolated from Hemachatus haemachatus (Ringhals cobra) venom. Its amino acid sequence was elucidated, and crystal structure was determined at 2.43 Å resolution. The overall fold is similar to other three-finger toxins. The structure and sequence analysis revealed that the fold is maintained by four highly conserved disulfide bonds. It exhibited highest similarity to particularly P-type cardiotoxins that are known to associate and perturb the membrane surface with their lipid binding sites. Also, the increased B value of hemachotoxin loop II suggests that loop II is flexible and may remain flexible until its interaction with membrane phospholipids. Based on the analysis, we predict hemachatoxin to be cardiotoxic/cytotoxic and our future experiments will be directed to characterize the activity of hemachatoxin.
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Affiliation(s)
| | - Sundramurthy Kumar
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Lissa Joseph
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail: (RMK); (JS)
| | - J. Sivaraman
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
- * E-mail: (RMK); (JS)
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Pharmacological characterization of α-elapitoxin-Al2a from the venom of the Australian pygmy copperhead (Austrelaps labialis): An atypical long-chain α-neurotoxin with only weak affinity for α7 nicotinic receptors. Biochem Pharmacol 2012; 84:851-63. [DOI: 10.1016/j.bcp.2012.06.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 06/22/2012] [Accepted: 06/25/2012] [Indexed: 11/19/2022]
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Song JK, Jo MR, Park MH, Song HS, An BJ, Song MJ, Han SB, Hong JT. Cell growth inhibition and induction of apoptosis by snake venom toxin in ovarian cancer cell via inactivation of nuclear factor κB and signal transducer and activator of transcription 3. Arch Pharm Res 2012; 35:867-76. [PMID: 22644854 DOI: 10.1007/s12272-012-0512-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/18/2011] [Accepted: 11/02/2011] [Indexed: 01/05/2023]
Abstract
Snake venom toxin from Vipera lebetina turanica induces apoptosis in many cancer cell lines, but there is no study about the apoptotic effect of snake venom toxin on human ovarian cancer cells. In this study, we investigated the apoptotic effect of snake venom toxin in human ovarian cancer PA-1 and SK-OV3 cells. Snake venom toxin dose dependently (0∼10 μg/mL) inhibited ovarian cancer cell growth with IC(50) values 4.5 μg/mL in PA-1 cells, and 6.5 μg/mL in SK-OV3 cells. Our results also showed that apoptotic cell death increased by snake venom toxin in a dose dependent manner (0∼10 μg/mL). Consistent with increased cell death, snake venom toxin increased the expression of pro-apoptotic protein Bax and caspase-3, but down-regulated anti-apoptotic protein Bcl-2. Untreated ovarian cancer cells showed a high DNA binding activity of nuclear factor B (NF-κB), but it was inhibited by snake venom toxin accompanied by inhibition of p50 and p65 translocation into the nucleus as well as phosphorylation of inhibitory κB. Snake venom toxin also inhibited DNA binding activity of the signal transducer and activator of transcription 3 (STAT3). Moreover, the combination treatment of NF-κB (salicylic acid, 1 or 5 μM) and STAT3 (stattic, 1 μM) with snake venom toxin (1 μg/mL) further enhanced cell growth inhibitory effects of snake venom toxin. These results showed that snake venom toxin from Vipera lebetina turanica caused apoptotic cell death of ovarian cancer cells through the inhibition of NF-κB and STAT3 signal, and suggested that snake venom toxin may be applicable as an anticancer agent for ovarian cancer.
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Affiliation(s)
- Ju Kyoung Song
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju, Korea
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Hone AJ, Meyer EL, McIntyre M, McIntosh JM. Nicotinic acetylcholine receptors in dorsal root ganglion neurons include the α6β4* subtype. FASEB J 2011; 26:917-26. [PMID: 22024738 DOI: 10.1096/fj.11-195883] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The α6-containing nicotinic acetylcholine receptors (nAChRs) have recently been implicated in diseases of the central nervous system (CNS), including Parkinson's disease and substance abuse. In contrast, little is known about the role of α6* nAChRs in the peripheral nervous system (where the asterisk denotes the possible presence of additional subunits). Dorsal root ganglia (DRG) neurons are known to express nAChRs with a pharmacology consistent with an α7, α3β4*, and α4β2* composition. Here we present evidence that DRG neurons also express α6* nAChRs. We used RT-PCR to show the presence of α6 subunit transcripts and patch-clamp electrophysiology together with subtype-selective α-conotoxins to pharmacologically characterize the nAChRs in rat DRG neurons. α-Conotoxin BuIA (500 nM) blocked acetylcholine-gated currents (I(ACh)) by 90.3 ± 3.0%; the recovery from blockade was very slow, indicating a predominance of α(x)β4* nAChRs. Perfusion with either 300 nM BuIA[T5A;P6O] or 200 nM MII[E11A], α-conotoxins that target the α6β4* subtype, blocked I(ACh) by 49.3 ± 5 and 46.7 ± 8%, respectively. In these neurons, I(ACh) was relatively insensitive to 200 nM ArIB[V11L;V16D] (9.4±2.0% blockade) or 500 nM PnIA (23.0±4% blockade), α-conotoxins that target α7 and α3β2*/α6β2* nAChRs, respectively. We conclude that α6β4* nAChRs are among the subtypes expressed by DRG, and to our knowledge, this is the first demonstration of α6β4* in neurons outside the CNS.
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Affiliation(s)
- Arik J Hone
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah, USA
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