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Cardoso-Arenas S, Clement H, Arenas I, Olvera F, Zamudio F, Caliskan F, Corrales-García LL, Corzo G. Recombinant expression and antigenicity of two peptide families of neurotoxins from Androctonus sp. J Venom Anim Toxins Incl Trop Dis 2022; 28:e20220026. [PMID: 36578820 PMCID: PMC9769139 DOI: 10.1590/1678-9199-jvatitd-2022-0026] [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: 05/26/2022] [Accepted: 09/23/2022] [Indexed: 12/23/2022] Open
Abstract
Background Scorpion neurotoxins such as those that modify the mammalian voltage-gated sodium ion channels (Nav) are the main responsible for scorpion envenomation. Their neutralization is crucial in the production of antivenoms against scorpion stings. Methods In the present study, two in silico designed genes - one that codes for a native neurotoxin from the venom of the Anatolian scorpion Androctonus crassicauda, named Acra 4 - and another non-native toxin - named consensus scorpion toxin (SccTx) obtained from the alignment of the primary structures of the most toxic neurotoxins from the Middle Eastern and North African scorpions - were recombinantly expressed in E. coli Origami. Results Following bacterial expression, the two expressed neurotoxins, hereafter named HisrAcra4 and HisrSccTx, were obtained from inclusion bodies. Both recombinant neurotoxins were obtained in multiple Cys-Cys isoforms. After refolding, the active protein fractions were identified with molecular masses of 8,947.6 and 9,989.1 Da for HisrAcra4 and HisrSccTx, respectively, which agreed with their expected theoretical masses. HisrAcra4 and HisrSccTx were used as antigens to immunize two groups of rabbits, to produce either anti-HisrAcra4 or anti-HisrSccTx serum antibodies, which in turn could recognize and neutralize neurotoxins from venoms of scorpion species from the Middle East and North Africa. The antibodies obtained from rabbits neutralized the 3LD50 of Androctonus australis, Leiurus quinquestriatus hebraeus and Buthus occitanus venoms, but they did not neutralize A. crassicauda and A. mauritanicus venoms. In addition, the anti-HisrAcra4 antibodies did not neutralize any of the five scorpion venoms tested. However, an antibody blend of anti-HisrAcra4 and anti-HisrSccTx was able to neutralize A. crassicauda and A. mauritanicus venoms. Conclusions Two recombinant Nav neurotoxins, from different peptide families, were used as antigens to generate IgGs for neutralizing scorpion venoms of species from the Middle East and North Africa.
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Affiliation(s)
- Samuel Cardoso-Arenas
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico
| | - Herlinda Clement
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico
| | - Iván Arenas
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico
| | - Felipe Olvera
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico
| | - Fernando Zamudio
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico
| | - Figen Caliskan
- Department of Biology, Faculty of Science and Letters, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Ligia Luz Corrales-García
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico.,Department of Food Sciences, School of Pharmaceutical and Food Sciences, University of Antioquia (UdeA), Medellín, Colombia
| | - Gerardo Corzo
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos, Mexico.,Correspondence:
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de Melo-Braga MN, Moreira RDS, Gervásio JHDB, Felicori LF. Overview of protein posttranslational modifications in Arthropoda venoms. J Venom Anim Toxins Incl Trop Dis 2022; 28:e20210047. [PMID: 35519418 PMCID: PMC9036706 DOI: 10.1590/1678-9199-jvatitd-2021-0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/27/2021] [Indexed: 11/22/2022] Open
Abstract
Accidents with venomous animals are a public health issue worldwide. Among the species involved in these accidents are scorpions, spiders, bees, wasps, and other members of the phylum Arthropoda. The knowledge of the function of proteins present in these venoms is important to guide diagnosis, therapeutics, besides being a source of a large variety of biotechnological active molecules. Although our understanding about the characteristics and function of arthropod venoms has been evolving in the last decades, a major aspect crucial for the function of these proteins remains poorly studied, the posttranslational modifications (PTMs). Comprehension of such modifications can contribute to better understanding the basis of envenomation, leading to improvements in the specificities of potential therapeutic toxins. Therefore, in this review, we bring to light protein/toxin PTMs in arthropod venoms by accessing the information present in the UniProtKB/Swiss-Prot database, including experimental and putative inferences. Then, we concentrate our discussion on the current knowledge on protein phosphorylation and glycosylation, highlighting the potential functionality of these modifications in arthropod venom. We also briefly describe general approaches to study "PTM-functional-venomics", herein referred to the integration of PTM-venomics with a functional investigation of PTM impact on venom biology. Furthermore, we discuss the bottlenecks in toxinology studies covering PTM investigation. In conclusion, through the mining of PTMs in arthropod venoms, we observed a large gap in this field that limits our understanding on the biology of these venoms, affecting the diagnosis and therapeutics development. Hence, we encourage community efforts to draw attention to a better understanding of PTM in arthropod venom toxins.
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Affiliation(s)
- Marcella Nunes de Melo-Braga
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Raniele da Silva Moreira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - João Henrique Diniz Brandão Gervásio
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Liza Figueiredo Felicori
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
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Hmaidi R, Ksouri A, Benabderrazek R, Antonietti V, Sonnet P, Gautier M, Bouhaouala-Zahar B, Ouadid-Ahidouch H. The Pharmacological and Structural Basis of the AahII–NaV1.5 Interaction and Modulation by the Anti-AahII Nb10 Nanobody. Front Pharmacol 2022; 13:821181. [PMID: 35295326 PMCID: PMC8918821 DOI: 10.3389/fphar.2022.821181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Scorpion α-toxins are neurotoxins that target the fast inactivation mechanism of voltage-gated sodium (NaV) channels leading to several neuro- and cardiotoxic effects in mammals. The toxin AahII is the most active α-toxin from the North African scorpion Androctonus australis Hector that slows the fast inactivation of NaV channels. To fight scorpion envenomation, an anti-AahII nanobody named NbAahII10 (Nb10) was developed. The efficiency of this nanobody has been evaluated in vivo on mice, but its mechanism of action at the cellular level remains unknown. Here we have shown that AahII toxin slows the fast inactivation of the adult cardiac NaV1.5 channels, expressed in HEK293 cells, in a dose-dependent manner, while current amplitude was not affected. The inactivation of NaV1.5 is slower by a factor of 4, 7, and 35 in the presence of [AahII] at 75, 150, and 300 nM, respectively. The washout partially reversed the toxin effect on inactivation from 8.3 ± 0.9 ms to 5.2 ± 1.2 ms at 75 nM. We have also demonstrated that the highly neutralizing Nb10 can fully reverse the effect of AahII toxin on the channel inactivation kinetics even at the 1:1 M ratio. However, the 1:0.5 M ratio is not able to neutralize completely the AahII effect. Therefore, the application of Nb10 promotes a partial abolishment of AahII action. Bioinformatic analysis and prediction of NaV1.5-driven docking with AahII show that Ala39 and Arg62 of AahII play a crucial role to establish a stable interaction through H-bound interactions with Gln1615 and Lys1616 (S3–S4 extracellular loop) and Asp1553 (S1–S2 loop) from the voltage-sensing domain IV (VSD4) of NaV1.5, respectively. From this, we notice that AahII shares the same contact surface with Nb10. This strongly suggests that Nb10 dynamically replaces AahII toxin from its binding site on the NaV1.5 channel. At the physiopathological level, Nb10 completely neutralized the enhancement of breast cancer cell invasion induced by AahII. In summary, for the first time, we made an electrophysiological and structural characterization of the neutralization potent of Nb10 against the α-scorpion toxin AahII in a cellular model overexpressing NaV1.5 channels.
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Affiliation(s)
- Riadh Hmaidi
- Laboratory of Biomolecules, Venoms, and Theranostic Applications, Institut Pasteur Tunis, University of Tunis El Manar, Tunis, Tunisia
- Laboratory of Cellular and Molecular Physiology UR 4667, UFR of Sciences, University of Picardie Jules Verne, Amiens, France
| | - Ayoub Ksouri
- Laboratory of Biomolecules, Venoms, and Theranostic Applications, Institut Pasteur Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Rahma Benabderrazek
- Laboratory of Biomolecules, Venoms, and Theranostic Applications, Institut Pasteur Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Viviane Antonietti
- Infectious Agents, Resistance and Chemotherapy UR 4294, UFR of Pharmacy, University of Picardie Jules Verne, Amiens, France
| | - Pascal Sonnet
- Infectious Agents, Resistance and Chemotherapy UR 4294, UFR of Pharmacy, University of Picardie Jules Verne, Amiens, France
| | - Mathieu Gautier
- Laboratory of Cellular and Molecular Physiology UR 4667, UFR of Sciences, University of Picardie Jules Verne, Amiens, France
- *Correspondence: Mathieu Gautier, ; Balkiss Bouhaouala-Zahar, ; Halima Ouadid-Ahidouch,
| | - Balkiss Bouhaouala-Zahar
- Laboratory of Biomolecules, Venoms, and Theranostic Applications, Institut Pasteur Tunis, University of Tunis El Manar, Tunis, Tunisia
- Medical School of Tunis, University of Tunis El Manar, Tunis, Tunisia
- *Correspondence: Mathieu Gautier, ; Balkiss Bouhaouala-Zahar, ; Halima Ouadid-Ahidouch,
| | - Halima Ouadid-Ahidouch
- Laboratory of Cellular and Molecular Physiology UR 4667, UFR of Sciences, University of Picardie Jules Verne, Amiens, France
- *Correspondence: Mathieu Gautier, ; Balkiss Bouhaouala-Zahar, ; Halima Ouadid-Ahidouch,
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Rivera-de-Torre E, Rimbault C, Jenkins TP, Sørensen CV, Damsbo A, Saez NJ, Duhoo Y, Hackney CM, Ellgaard L, Laustsen AH. Strategies for Heterologous Expression, Synthesis, and Purification of Animal Venom Toxins. Front Bioeng Biotechnol 2022; 9:811905. [PMID: 35127675 PMCID: PMC8811309 DOI: 10.3389/fbioe.2021.811905] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Animal venoms are complex mixtures containing peptides and proteins known as toxins, which are responsible for the deleterious effect of envenomations. Across the animal Kingdom, toxin diversity is enormous, and the ability to understand the biochemical mechanisms governing toxicity is not only relevant for the development of better envenomation therapies, but also for exploiting toxin bioactivities for therapeutic or biotechnological purposes. Most of toxinology research has relied on obtaining the toxins from crude venoms; however, some toxins are difficult to obtain because the venomous animal is endangered, does not thrive in captivity, produces only a small amount of venom, is difficult to milk, or only produces low amounts of the toxin of interest. Heterologous expression of toxins enables the production of sufficient amounts to unlock the biotechnological potential of these bioactive proteins. Moreover, heterologous expression ensures homogeneity, avoids cross-contamination with other venom components, and circumvents the use of crude venom. Heterologous expression is also not only restricted to natural toxins, but allows for the design of toxins with special properties or can take advantage of the increasing amount of transcriptomics and genomics data, enabling the expression of dormant toxin genes. The main challenge when producing toxins is obtaining properly folded proteins with a correct disulfide pattern that ensures the activity of the toxin of interest. This review presents the strategies that can be used to express toxins in bacteria, yeast, insect cells, or mammalian cells, as well as synthetic approaches that do not involve cells, such as cell-free biosynthesis and peptide synthesis. This is accompanied by an overview of the main advantages and drawbacks of these different systems for producing toxins, as well as a discussion of the biosafety considerations that need to be made when working with highly bioactive proteins.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Esperanza Rivera-de-Torre, ; Andreas H. Laustsen,
| | - Charlotte Rimbault
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Timothy P. Jenkins
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Christoffer V. Sørensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Anna Damsbo
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Natalie J. Saez
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Yoan Duhoo
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Celeste Menuet Hackney
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Lars Ellgaard
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Esperanza Rivera-de-Torre, ; Andreas H. Laustsen,
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Bayatzadeh MA, Zare Mirakabadi A, Babaei N, Doulah A, Doosti A. Expression and purification of recombinant alpha-toxin AnCra1 from the scorpion Androctonus crassicauda and its functional characterization on mammalian sodium channels. Mol Biol Rep 2021; 48:6303-6312. [PMID: 34379289 DOI: 10.1007/s11033-021-06624-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/03/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Alpha-scorpion toxins with long-chain peptide and four disulfide bonds represent diverse pharmacological profiles for various subtypes of voltage-gated sodium channels. Obtaining the natural toxins are difficult and time-consuming process, which represents the major difficulty to interpreting analysis of their structural and functional properties. METHODS AND RESULTS This study describes the toxin peptide and plasmid construct containing the gene coding for mammalian toxin AnCra1 from the scorpion Androctonus crassicauda venom. We have established genetic construction of fusion protein in pET32a + vector containing thioredoxin (Trx-tag), enterokinase cleavage site and 6xhistidine-tag for efficient expression in Escherichia coli strain RG2 (DE3). The soluble expressed peptide, then purified by Ni-NTA resin affinity chromatography and its purity was confirmed by reverse-phase HPLC and mass spectrometry (7433.54 Da.). The electrophysiological data showed that recombinant AnCra1 selectively inhibits the fast inactivation of hNav1.7 channel (EC50 = 136.7 ± 6.6 nM). CONCLUSIONS Our findings demonstrate that the AnCra1 is structurally and functionally analogous to alpha excitatory toxins; furthermore, expression and purification of bioactive scorpion toxins in bacterial cells can be a practicable and efficient way to obtain a novel source of toxin peptides as tools to study the function and physiological responses of ion channels.
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Affiliation(s)
- Mohammad Ali Bayatzadeh
- Department of Molecular Cell Biology and Genetics, Bushehr Branch, Islamic Azad University, Bushehr, Iran
| | - Abbas Zare Mirakabadi
- Venomous Animals and Antivenom Production Department, Razi Vaccine and Serum Research Institute, Agricultural Research- Education and Extension Organization, Hesarak, Karaj, Alborz, Iran.
| | - Nahid Babaei
- Department of Molecular Cell Biology and Genetics, Bushehr Branch, Islamic Azad University, Bushehr, Iran
| | - Abdolhassan Doulah
- Department of Nursing, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
| | - Abbas Doosti
- Biotechnology Research Center, Islamic Azad University, Shahrekord, Iran
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New Insectotoxin from Tibellus Oblongus Spider Venom Presents Novel Adaptation of ICK Fold. Toxins (Basel) 2021; 13:toxins13010029. [PMID: 33406803 PMCID: PMC7824768 DOI: 10.3390/toxins13010029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/21/2020] [Accepted: 12/30/2020] [Indexed: 11/17/2022] Open
Abstract
The Tibellus oblongus spider is an active predator that does not spin webs and remains poorly investigated in terms of venom composition. Here, we present a new toxin, named Tbo-IT2, predicted by cDNA analysis of venom glands transcriptome. The presence of Tbo-IT2 in the venom was confirmed by proteomic analyses using the LC-MS and MS/MS techniques. The distinctive features of Tbo-IT2 are the low similarity of primary structure with known animal toxins and the unusual motif of 10 cysteine residues distribution. Recombinant Tbo-IT2 (rTbo-IT2), produced in E. coli using the thioredoxin fusion protein strategy, was structurally and functionally studied. rTbo-IT2 showed insecticidal activity on larvae of the housefly Musca domestica (LD100 200 μg/g) and no activity on the panel of expressed neuronal receptors and ion channels. The spatial structure of the peptide was determined in a water solution by NMR spectroscopy. The Tbo-IT2 structure is a new example of evolutionary adaptation of a well-known inhibitor cystine knot (ICK) fold to 5 disulfide bonds configuration, which determines additional conformational stability and gives opportunities for insectotoxicity and probably some other interesting features.
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C-Terminal Amidation of Chlorotoxin Does Not Affect Tumour Cell Proliferation and Has No Effect on Toxin Cytotoxicity. Int J Pept Res Ther 2020. [DOI: 10.1007/s10989-020-10117-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Johnson SR, Rikli HG. Aspartic Acid Isomerization Characterized by High Definition Mass Spectrometry Significantly Alters the Bioactivity of a Novel Toxin from Poecilotheria. Toxins (Basel) 2020; 12:E207. [PMID: 32218140 PMCID: PMC7232244 DOI: 10.3390/toxins12040207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 11/25/2022] Open
Abstract
Research in toxinology has created a pharmacological paradox. With an estimated 220,000 venomous animals worldwide, the study of peptidyl toxins provides a vast number of effector molecules. However, due to the complexity of the protein-protein interactions, there are fewer than ten venom-derived molecules on the market. Structural characterization and identification of post-translational modifications are essential to develop biological lead structures into pharmaceuticals. Utilizing advancements in mass spectrometry, we have created a high definition approach that fuses conventional high-resolution MS-MS with ion mobility spectrometry (HDMSE) to elucidate these primary structure characteristics. We investigated venom from ten species of "tiger" spider (Genus: Poecilotheria) and discovered they contain isobaric conformers originating from non-enzymatic Asp isomerization. One conformer pair conserved in five of ten species examined, denominated PcaTX-1a and PcaTX-1b, was found to be a 36-residue peptide with a cysteine knot, an amidated C-terminus, and isoAsp33Asp substitution. Although the isomerization of Asp has been implicated in many pathologies, this is the first characterization of Asp isomerization in a toxin and demonstrates the isomerized product's diminished physiological effects. This study establishes the value of a HDMSE approach to toxin screening and characterization.
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Affiliation(s)
- Stephen R. Johnson
- Carbon Dynamics Institute LLC, Sherman, IL 62684, USA
- Chemistry Department, University of Illinois Springfield, Springfield, IL 62703, USA
| | - Hillary G. Rikli
- College of Liberal Arts & Sciences, University of Illinois Springfield, Springfield, IL 62703, USA;
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Rincón-Cortés CA, Olamendi-Portugal T, Carcamo-Noriega EN, Santillán EG, Zuñiga FZ, Reyes-Montaño EA, Vega Castro NA, Possani LD. Structural and functional characterization of toxic peptides purified from the venom of the Colombian scorpion Tityus macrochirus. Toxicon 2019; 169:5-11. [PMID: 31402191 DOI: 10.1016/j.toxicon.2019.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/01/2019] [Accepted: 07/23/2019] [Indexed: 01/09/2023]
Abstract
The soluble venom of the scorpion Tityus macrochirus was separated by chromatographic procedures and three homogeneous peptides were obtained and their primary structures were determined. They were called: Tma1-Tma3, from the abbreviated name of the scorpion. Tma1 is a peptide containing 65 amino acids with four disulfide linkages and a molecular weight of 7386.2 Da. It is a mammalian toxin, shown to affect human sodium-channels sub-types hNav1.6 and hNav1.4. Tma2 and Tma3 are peptides containing 69 amino acids linked by four disulfide bonds, molecular weights 7819.7 and 7830.0 Da, respectively. They do not affect human sodium-channels but are lethal to insects (crickets). A phylogenic analysis of the three peptides and those of other toxic peptides isolated from the genus Tityus and Centruroides were grouped together and analyzed, permitting to obtain a topology with two main clades, one includes most sodium-channel anti-insect scorpion toxins and others includes mostly sodium-channel scorpion toxins anti-mammalian. Tma1 segregates among a group of well-studied β-class toxins of other Tityus species such as T. discrepans, T. obscurus and T. pachyurus. Tma2 and Tma3 are associated with anti-insect toxins, particularly with one of T. obscurus. This phylogenetic analysis confirms and enforces our experimental results obtained with these three new sodium-channel scorpion toxins.
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Affiliation(s)
- Clara Andrea Rincón-Cortés
- Grupo de Investigación en Proteínas, Departamento de Química, Universidad Nacional de Colombia, Bogotá, D.C., Colombia; Universidad de Ciencias Aplicadas y Ambientales, U.D.C.A., Bogotá, D.C., Colombia
| | - Timoteo Olamendi-Portugal
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Edson Norberto Carcamo-Noriega
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Edmundo González Santillán
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Fernando Zamudio Zuñiga
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Edgar Antonio Reyes-Montaño
- Grupo de Investigación en Proteínas, Departamento de Química, Universidad Nacional de Colombia, Bogotá, D.C., Colombia
| | - Nohora Angélica Vega Castro
- Grupo de Investigación en Proteínas, Departamento de Química, Universidad Nacional de Colombia, Bogotá, D.C., Colombia
| | - Lourival Domingos Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico.
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Clairfeuille T, Cloake A, Infield DT, Llongueras JP, Arthur CP, Li ZR, Jian Y, Martin-Eauclaire MF, Bougis PE, Ciferri C, Ahern CA, Bosmans F, Hackos DH, Rohou A, Payandeh J. Structural basis of α-scorpion toxin action on Na v channels. Science 2019; 363:science.aav8573. [PMID: 30733386 DOI: 10.1126/science.aav8573] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/28/2019] [Indexed: 01/25/2023]
Abstract
Fast inactivation of voltage-gated sodium (Nav) channels is essential for electrical signaling, but its mechanism remains poorly understood. Here we determined the structures of a eukaryotic Nav channel alone and in complex with a lethal α-scorpion toxin, AaH2, by electron microscopy, both at 3.5-angstrom resolution. AaH2 wedges into voltage-sensing domain IV (VSD4) to impede fast activation by trapping a deactivated state in which gating charge interactions bridge to the acidic intracellular carboxyl-terminal domain. In the absence of AaH2, the S4 helix of VSD4 undergoes a ~13-angstrom translation to unlatch the intracellular fast-inactivation gating machinery. Highlighting the polypharmacology of α-scorpion toxins, AaH2 also targets an unanticipated receptor site on VSD1 and a pore glycan adjacent to VSD4. Overall, this work provides key insights into fast inactivation, electromechanical coupling, and pathogenic mutations in Nav channels.
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Affiliation(s)
- Thomas Clairfeuille
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Alexander Cloake
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA.,Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Daniel T Infield
- Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, IA, USA
| | - José P Llongueras
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Zhong Rong Li
- Department of Biomolecular Resources, Genentech Inc., South San Francisco, CA, USA
| | - Yuwen Jian
- Department of Neuroscience, Genentech Inc., South San Francisco, CA, USA
| | | | - Pierre E Bougis
- Aix Marseille Université, CNRS, LNC, UMR 7291, 13003 Marseille, France
| | - Claudio Ciferri
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, IA, USA.
| | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, 9000 Ghent, Belgium.
| | - David H Hackos
- Department of Neuroscience, Genentech Inc., South San Francisco, CA, USA.
| | - Alexis Rohou
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA.
| | - Jian Payandeh
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA.
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Amorim FG, Cordeiro FA, Pinheiro-Júnior EL, Boldrini-França J, Arantes EC. Microbial production of toxins from the scorpion venom: properties and applications. Appl Microbiol Biotechnol 2018; 102:6319-6331. [PMID: 29858954 DOI: 10.1007/s00253-018-9122-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/19/2018] [Accepted: 05/21/2018] [Indexed: 12/14/2022]
Abstract
Scorpion venom are composed mainly of bioactive proteins and peptides that may serve as lead compounds for the design of biotechnological tools and therapeutic drugs. However, exploring the therapeutic potential of scorpion venom components is mainly impaired by the low yield of purified toxins from milked venom. Therefore, production of toxin-derived peptides and proteins by heterologous expression is the strategy of choice for research groups and pharmaceutical industry to overcome this limitation. Recombinant expression in microorganisms is often the first choice, since bacteria and yeast systems combine high level of recombinant protein expression, fast cell growth and multiplication and simple media requirement. Herein, we present a comprehensive revision, which describes the scorpion venom components that were produced in their recombinant forms using microbial systems. In addition, we highlight the pros and cons of performing the heterologous expression of these compounds, regarding the particularities of each microorganism and how these processes can affect the application of these venom components. The most used microbial system in the heterologous expression of scorpion venom components is Escherichia coli (85%), and among all the recombinant venom components produced, 69% were neurotoxins. This review may light up future researchers in the choice of the best expression system to produce scorpion venom components of interest.
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Affiliation(s)
- Fernanda Gobbi Amorim
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil.
| | - Francielle Almeida Cordeiro
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Ernesto Lopes Pinheiro-Júnior
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Johara Boldrini-França
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Eliane Candiani Arantes
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil.
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Johnson SR, Rikli HG, Schmidt JO, Evans MS. A reexamination of poneratoxin from the venom of the bullet ant Paraponera clavata. Peptides 2017; 98:51-62. [PMID: 27266841 DOI: 10.1016/j.peptides.2016.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/29/2016] [Accepted: 05/31/2016] [Indexed: 12/19/2022]
Abstract
In 1991, Piek et al. [45] described a voltage-gated sodium channel (VGSC) modifier from "bullet ant" (Paraponera clavata) venom they called poneratoxin (PoTx). Using UV chromatography and Edman degradation they showed two "identical peptides" of 25 residues. We reinvestigated PoTx using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-TMS). De novo sequencing showed the two peptides were actually structurally different peptides: the originally described PoTx and a glycyl pro-peptide (glycyl-PoTx) that lacks C-terminus amidation. We examined P. clavata venom from different geographical locations and discovered two additional PoTx analogs: an A23E substitution analog and a D22N; A23V substitutions analog. We tested PoTx and these three natural analogs on the mammalian sensory voltage-gated sodium channel, Nav1.7, using whole cell voltage-clamp. PoTx and each analog induced slowly activating currents in response to small depolarizing steps and sustained currents due to blockade of channel inactivation, similar to that described previously in skeletal muscle [19]. Glycyl-PoTx had the same potency and efficacy as PoTx. A23E PoTx, with a decrease in both C-terminal net positive charge and hydrophobicity, had an eight-fold reduction in potency compared to PoTx. In contrast, the D22N; A23V PoTx, with an increase in both C-terminal net positive charge and hydrophobicity, had a nearly five-fold increase in potency compared to PoTx. We found that changes in PoTx C-terminus caused a significant change in PoTx potency.
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Affiliation(s)
- Stephen R Johnson
- Department of Biology, University of Illinois Springfield, Springfield, IL, United States; Department of Chemistry, University of Illinois Springfield, Springfield, IL, United States; Carbon Dynamics Institute, LLC, Sherman, IL, United States.
| | - Hillary G Rikli
- Department of Biology, University of Illinois Springfield, Springfield, IL, United States; Department of Chemistry, University of Illinois Springfield, Springfield, IL, United States
| | | | - M Steven Evans
- Department of Neurology, University of Louisville, Louisville, KY, United States
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Moreels L, Peigneur S, Yamaguchi Y, Vriens K, Waelkens E, Zhu S, Thevissen K, Cammue BPA, Sato K, Tytgat J. Expanding the pharmacological profile of κ-hefutoxin 1 and analogues: A focus on the inhibitory effect on the oncogenic channel K v10.1. Peptides 2017; 98:43-50. [PMID: 27578329 DOI: 10.1016/j.peptides.2016.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
Peptide toxins, such as scorpion peptides, are interesting lead compounds in the search for novel drugs. In this paper, the focus is on the scorpion peptide κ-hefutoxin 1. This peptide displays a cysteine-stabilized helix-loop-helix fold (CSα/α) and is known to be a weak Kv1.x inhibitor. Due to the low affinity of κ-hefutoxin 1 for these channels, it is assumed that the main target(s) of κ-hefutoxin 1 remain(s) unknown. In order to identify novel targets, electrophysiological measurements and antifungal assays were performed. The effect of κ-hefutoxin 1 was previously evaluated on a panel of 11 different voltage-gated potassium channels. Here, we extended this target screening with the oncogenic potassium channel Kv10.1. κ-Hefutoxin 1 was able to inhibit this channel in a dose-dependent manner (IC50∼26μM). Although the affinity is rather low, this is the first peptide toxin ever described to be a Kv10.1 inhibitor. The structure-activity relationship of κ-hefutoxin 1 on Kv10.1 was investigated by testing eight κ-hefutoxin 1 variants using the two-electrode voltage clamp technique. Several important amino acid residues were identified; the functional dyad residues (Tyr5 and Lys19), N-terminal residues (Gly1 and His2) and the amidated C-terminal residue (Cys22). Since the CSα/α fold is also found in a class of antifungal plant peptides, the α-hairpinines, we investigated the antifungal activity of κ-hefutoxin 1. κ-Hefutoxin 1 showed low activity against the plant pathogen Fusarium culmorum and no activity against three other yeast and fungal species, even at high concentrations (∼100μM).
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Affiliation(s)
- Lien Moreels
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Yoko Yamaguchi
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Kim Vriens
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Etienne Waelkens
- Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, Campus Gasthuisberg, O&N1, Herestraat 49, PO Box 901, 3000 Leuven, Belgium.
| | - Shunyi Zhu
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium; VIB Department of Plant Systems Biology, Technologiepark 927, 9052 Ghent, Belgium.
| | - Kazuki Sato
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
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Nakib I, Martin-Eauclaire MF, Laraba-Djebari F. Involvement of Cholinergic and Adrenergic Receptors in Pathogenesis and Inflammatory Response Induced by Alpha-Neurotoxin Bot III of Scorpion Venom. Inflammation 2016; 39:1670-80. [PMID: 27395044 DOI: 10.1007/s10753-016-0401-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bot III neurotoxin is the most lethal α neurotoxin purified from Buthus occitanus tunetanus scorpion venom. This toxin binds to the voltage-gated sodium channel of excitable cells and blocks its inactivation, inducing an increased release of neurotransmitters (acetylcholine and catecholamines). This study aims to elucidate the involvement of cholinergic and adrenergic receptors in pathogenesis and inflammatory response triggered by this toxin. Injection of Bot III to animals induces an increase of peroxidase activities, an imbalance of oxidative status, tissue damages in lung parenchyma, and myocardium correlated with metabolic disorders. The pretreatment with nicotine (nicotinic receptor agonist) or atropine (muscarinic receptor antagonist) protected the animals from almost all disorders caused by Bot III toxin, especially the immunological alterations. Bisoprolol administration (selective β1 adrenergic receptor antagonist) was also efficient in the protection of animals, mainly on tissue damage. Propranolol (non-selective adrenergic receptor antagonist) showed less effect. These results suggest that both cholinergic and adrenergic receptors are activated in the cardiopulmonary manifestations induced by Bot III. Indeed, the muscarinic receptor appears to be more involved than the nicotinic one, and the β1 adrenergic receptor seems to dominate the β2 receptor. These results showed also that the activation of nicotinic receptor leads to a significant protection of animals against Bot III toxin effect. These findings supply a supplementary data leading to better understanding of the mechanism triggered by scorpionic neurotoxins and suggest the use of drugs targeting these receptors, especially the nicotinic one in order to counteract the inflammatory response observed in scorpion envenomation.
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Affiliation(s)
- Imene Nakib
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32, El-Alia Bab Ezzouar, 16111, Algiers, Algeria
| | - Marie-France Martin-Eauclaire
- Aix-Marseille University, CNRS UMR7290 CRN2M, IFR Jean-Roche, Université de la Méditerranée, Faculté de Médecine Nord, Bd Pierre Dramard, 13916, Marseille, Cedex 20, France
| | - Fatima Laraba-Djebari
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32, El-Alia Bab Ezzouar, 16111, Algiers, Algeria.
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Estrada G, Silva AO, Villegas E, Ortiz E, Beirão PSL, Corzo G. Heterologous expression of five disulfide-bonded insecticidal spider peptides. Toxicon 2016; 119:152-8. [PMID: 27263806 DOI: 10.1016/j.toxicon.2016.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/25/2016] [Accepted: 06/01/2016] [Indexed: 12/31/2022]
Abstract
The genes of the five disulfide-bonded peptide toxins 1 and 2 (named Oxytoxins or Oxotoxins) from the spider Oxyopes lineatus were cloned into the expression vector pQE30 containing a 6His-tag and a Factor Xa proteolytic cleavage region. These two recombinant vectors were transfected into Escherichia coli BL21 cells and expressed under induction with isopropyl thiogalactoside (IPTG). The product of each gene was named HisrOxyTx1 or HisrOxyTx2, and the protein expression was ca 14 and 6 mg/L of culture medium, respectively. Either recombinant toxin HisrOxyTx1 or HisrOxyTx2 were found exclusively in inclusion bodies, which were solubilized using a chaotropic agent, and then, purified using affinity chromatography and reverse-phase HPLC (RP-HPLC). The HisrOxyTx1 and HisrOxyTx2 products, obtained from the affinity chromatographic step, showed several peptide fractions having the same molecular mass of 9913.1 and 8030.1 Da, respectively, indicating that both HisrOxyTx1 and HisrOxyTx2 were oxidized forming several distinct disulfide bridge arrangements. The isoforms of both HisrOxyTx1 and HisrOxyTx2 after DTT reduction eluted from the column as a single protein component of 9923 and 8040 Da, respectively. In vitro folding of either HisrOxyTx1 or HisrOxyTx2 yielded single oxidized components, which were cleaved independently by the proteolytic enzyme Factor Xa to give the recombinant peptides rOxyTx1 and rOxyTx2. The experimental molecular masses of rOxyTx1 and rOxyTx2 were 8059.0 and 6176.4 Da, respectively, which agree with their expected theoretical masses. The recombinant peptides rOxyTx1 and rOxyTx2 showed lower but comparable toxicity to the native toxins when injected into lepidopteran larvae; furthermore, rOxyTx1 was able to inhibit calcium ion currents on dorsal unpaired median (DUM) neurons from Periplaneta americana.
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Affiliation(s)
- Georgina Estrada
- Centro de Investigación Científica de Yucatán, A.C. Calle 43 No.130, Mérida, Yucatán, 97200, Mexico
| | - Anita O Silva
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, UFMG, Av. Antonio Carlos 6627, 31270-901, Belo Horizonte, Brazil
| | - Elba Villegas
- Centro de Investigación en Biotecnología - UAEM, Av. Universidad 1001, Cuernavaca, Morelos, 62209, Mexico
| | - Ernesto Ortiz
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca, Morelos, 61500, Mexico
| | - Paulo S L Beirão
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, UFMG, Av. Antonio Carlos 6627, 31270-901, Belo Horizonte, Brazil
| | - 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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Carmo AO, Chatzaki M, Horta CCR, Magalhães BF, Oliveira-Mendes BBR, Chávez-Olórtegui C, Kalapothakis E. Evolution of alternative methodologies of scorpion antivenoms production. Toxicon 2015; 97:64-74. [PMID: 25701676 DOI: 10.1016/j.toxicon.2015.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 11/10/2014] [Accepted: 02/17/2015] [Indexed: 12/23/2022]
Abstract
Scorpionism represents a serious public health problem resulting in the death of children and debilitated individuals. Scorpion sting treatment employs various strategies including the use of specific medicines such as antiserum, especially for patients with severe symptoms. In 1909 Charles Todd described the production of an antiserum against the venom of the scorpion Buthus quinquestriatus. Based on Todd's work, researchers worldwide began producing antiserum using the same approach i.e., immunization of horses with crude venom as antigen. Despite achieving satisfactory results using this approach, researchers in this field have developed alternative approaches for the production of scorpion antivenom serum. In this review, we describe the work published by experts in toxinology to the development of scorpion venom antiserum. Methods and results describing the use of specific antigens, detoxified venom or toxins, purified toxins and or venom fractions, native toxoids, recombinant toxins, synthetic peptides, monoclonal and recombinant antibodies, and alternative animal models are presented.
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Affiliation(s)
- A O Carmo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
| | - M Chatzaki
- Department of Molecular Biology & Genetics, Democritus University of Thrace, University Campus, 69100 Komotini, Greece.
| | - C C R Horta
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
| | - B F Magalhães
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
| | - B B R Oliveira-Mendes
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
| | - C Chávez-Olórtegui
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
| | - E Kalapothakis
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil.
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17
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Coelho V, Cremonez C, Anjolette F, Aguiar J, Varanda W, Arantes E. Functional and structural study comparing the C-terminal amidated β-neurotoxin Ts1 with its isoform Ts1-G isolated from Tityus serrulatus venom. Toxicon 2014; 83:15-21. [DOI: 10.1016/j.toxicon.2014.02.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 10/25/2022]
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Baracchi D, Mazza G, Michelucci E, Pieraccini G, Turillazzi S, Moneti G. Top-down sequencing of Apis dorsata apamin by MALDI-TOF MS and evidence of its inactivity against microorganisms. Toxicon 2013; 71:105-12. [DOI: 10.1016/j.toxicon.2013.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/18/2013] [Accepted: 05/22/2013] [Indexed: 11/25/2022]
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Chugunov AO, Koromyslova AD, Berkut AA, Peigneur S, Tytgat J, Polyansky AA, Pentkovsky VM, Vassilevski AA, Grishin EV, Efremov RG. Modular organization of α-toxins from scorpion venom mirrors domain structure of their targets, sodium channels. J Biol Chem 2013; 288:19014-27. [PMID: 23637230 DOI: 10.1074/jbc.m112.431650] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
To gain success in the evolutionary "arms race," venomous animals such as scorpions produce diverse neurotoxins selected to hit targets in the nervous system of prey. Scorpion α-toxins affect insect and/or mammalian voltage-gated sodium channels (Na(v)s) and thereby modify the excitability of muscle and nerve cells. Although more than 100 α-toxins are known and a number of them have been studied into detail, the molecular mechanism of their interaction with Na(v)s is still poorly understood. Here, we employ extensive molecular dynamics simulations and spatial mapping of hydrophobic/hydrophilic properties distributed over the molecular surface of α-toxins. It is revealed that despite the small size and relatively rigid structure, these toxins possess modular organization from structural, functional, and evolutionary perspectives. The more conserved and rigid "core module" is supplemented with the "specificity module" (SM) that is comparatively flexible and variable and determines the taxon (mammal versus insect) specificity of α-toxin activity. We further show that SMs in mammal toxins are more flexible and hydrophilic than in insect toxins. Concomitant sequence-based analysis of the extracellular loops of Na(v)s suggests that α-toxins recognize the channels using both modules. We propose that the core module binds to the voltage-sensing domain IV, whereas the more versatile SM interacts with the pore domain in repeat I of Na(v)s. These findings corroborate and expand the hypothesis on different functional epitopes of toxins that has been reported previously. In effect, we propose that the modular structure in toxins evolved to match the domain architecture of Na(v)s.
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Affiliation(s)
- Anton O Chugunov
- M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.
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Durek T, Vetter I, Wang CIA, Motin L, Knapp O, Adams DJ, Lewis RJ, Alewood PF. Chemical engineering and structural and pharmacological characterization of the α-scorpion toxin OD1. ACS Chem Biol 2013; 8:1215-22. [PMID: 23527544 DOI: 10.1021/cb400012k] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Scorpion α-toxins are invaluable pharmacological tools for studying voltage-gated sodium channels, but few structure-function studies have been undertaken due to their challenging synthesis. To address this deficiency, we report a chemical engineering strategy based upon native chemical ligation. The chemical synthesis of α-toxin OD1 was achieved by chemical ligation of three unprotected peptide segments. A high resolution X-ray structure (1.8 Å) of synthetic OD1 showed the typical βαββ α-toxin fold and revealed important conformational differences in the pharmacophore region when compared with other α-toxin structures. Pharmacological analysis of synthetic OD1 revealed potent α-toxin activity (inhibition of fast inactivation) at Nav1.7, as well as Nav1.4 and Nav1.6. In addition, OD1 also produced potent β-toxin activity at Nav1.4 and Nav1.6 (shift of channel activation in the hyperpolarizing direction), indicating that OD1 might interact at more than one site with Nav1.4 and Nav1.6. Investigation of nine OD1 mutants revealed that three residues in the reverse turn contributed significantly to selectivity, with the triple OD1 mutant (D9K, D10P, K11H) being 40-fold more selective for Nav1.7 over Nav1.6, while OD1 K11V was 5-fold more selective for Nav1.6 than Nav1.7. This switch in selectivity highlights the importance of the reverse turn for engineering α-toxins with altered selectivity at Nav subtypes.
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Affiliation(s)
- Thomas Durek
- Division of
Chemistry and Structural
Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
4072
| | - Irina Vetter
- Division of
Chemistry and Structural
Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
4072
| | - Ching-I Anderson Wang
- Division of
Chemistry and Structural
Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
4072
| | - Leonid Motin
- Health Innovations
Research
Institute, RMIT University, Victoria, Australia
3083
| | - Oliver Knapp
- Health Innovations
Research
Institute, RMIT University, Victoria, Australia
3083
| | - David J. Adams
- Health Innovations
Research
Institute, RMIT University, Victoria, Australia
3083
| | - Richard J. Lewis
- Division of
Chemistry and Structural
Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
4072
| | - Paul F. Alewood
- Division of
Chemistry and Structural
Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
4072
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Chen R, Chung SH. Binding Modes and Functional Surface of Anti-mammalian Scorpion α-Toxins to Sodium Channels. Biochemistry 2012; 51:7775-82. [DOI: 10.1021/bi300776g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Rong Chen
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Shin-Ho Chung
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
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22
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Arginine Residues in the C-terminal and their Relationship with the Analgesic Activity of the Toxin from the Chinese Scorpion Buthus martensii Karsch (BmK AGP-SYPU1). Appl Biochem Biotechnol 2012; 168:247-55. [DOI: 10.1007/s12010-012-9768-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 06/04/2012] [Indexed: 10/28/2022]
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23
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Cologna CT, Peigneur S, Rustiguel JK, Nonato MC, Tytgat J, Arantes EC. Investigation of the relationship between the structure and function of Ts2, a neurotoxin from Tityus serrulatus venom. FEBS J 2012; 279:1495-504. [PMID: 22356164 DOI: 10.1111/j.1742-4658.2012.08545.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Scorpion toxins targeting voltage-gated sodium (Na(V)) channels are peptides that comprise 60-76 amino acid residues cross-linked by four disulfide bridges. These toxins can be divided in two groups (α and β toxins), according to their binding properties and mode of action. The scorpion α-toxin Ts2, previously described as a β-toxin, was purified from the venom of Tityus serrulatus, the most dangerous Brazilian scorpion. In this study, seven mammalian Na(V) channel isoforms (rNa(V)1.2, rNa(V)1.3, rNa(V)1.4, hNa(V)1.5, mNa(V)1.6, rNa(V)1.7 and rNa(V)1.8) and one insect Na(V) channel isoform (DmNa(V)1) were used to investigate the subtype specificity and selectivity of Ts2. The electrophysiology assays showed that Ts2 inhibits rapid inactivation of Na(V)1.2, Na(V)1.3, Na(V)1.5, Na(V)1.6 and Na(V)1.7, but does not affect Na(V)1.4, Na(V)1.8 or DmNa(V)1. Interestingly, Ts2 significantly shifts the voltage dependence of activation of Na(V)1.3 channels. The 3D structure of this toxin was modeled based on the high sequence identity (72%) shared with Ts1, another T. serrulatus toxin. The overall fold of the Ts2 model consists of three β-strands and one α-helix, and is arranged in a triangular shape forming a cysteine-stabilized α-helix/β-sheet (CSαβ) motif.
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Affiliation(s)
- Camila T Cologna
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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di Tommaso A, Juste MO, Martin-Eauclaire MF, Dimier-Poisson I, Billiald P, Aubrey N. Diabody mixture providing full protection against experimental scorpion envenoming with crude Androctonus australis venom. J Biol Chem 2012; 287:14149-56. [PMID: 22375011 PMCID: PMC3340170 DOI: 10.1074/jbc.m112.348912] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Indexed: 01/24/2023] Open
Abstract
Androctonus australis is primarily involved in envenomations in North Africa, notably in Tunisia and Algeria, and constitutes a significant public health problem in this region. The toxicity of the venom is mainly due to various neurotoxins that belong to two distinct structural and immunological groups, group I (the AahI and AahIII toxins) and group II (AahII). Here, we report the use of a diabody mixture in which the molar ratio matches the characteristics of toxins and polymorphism of the venom. The mixture consists of the Db9C2 diabody (anti-group I) and the Db4C1op diabody (anti-AahII), the latter being modified to facilitate in vitro production and purification. The effectiveness of the antivenom was tested in vivo under conditions simulating scorpion envenomation. The intraperitoneal injection of 30 μg of the diabody mixture protected almost all the mice exposed to 3 LD(50) s.c. of venom. We also show that the presence of both diabodies is necessary for the animals to survive. Our results are the first demonstration of the strong protective power of small quantities of antivenom used in the context of severe envenomation with crude venom.
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Affiliation(s)
- Anne di Tommaso
- From the Université de Tours, UMR1282 Infectiologie et Santé Publique, 37200 Tours
- Institut National de la Recherche Agronomique, UMR1282 Infectiologie et Santé Publique, 37380 Nouzilly
| | - Matthieu O. Juste
- From the Université de Tours, UMR1282 Infectiologie et Santé Publique, 37200 Tours
- Institut National de la Recherche Agronomique, UMR1282 Infectiologie et Santé Publique, 37380 Nouzilly
| | | | - Isabelle Dimier-Poisson
- From the Université de Tours, UMR1282 Infectiologie et Santé Publique, 37200 Tours
- Institut National de la Recherche Agronomique, UMR1282 Infectiologie et Santé Publique, 37380 Nouzilly
| | | | - Nicolas Aubrey
- From the Université de Tours, UMR1282 Infectiologie et Santé Publique, 37200 Tours
- Institut National de la Recherche Agronomique, UMR1282 Infectiologie et Santé Publique, 37380 Nouzilly
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Quintero-Hernández V, Ortiz E, Rendón-Anaya M, Schwartz EF, Becerril B, Corzo G, Possani LD. Scorpion and spider venom peptides: gene cloning and peptide expression. Toxicon 2011; 58:644-63. [PMID: 21978889 DOI: 10.1016/j.toxicon.2011.09.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/08/2011] [Accepted: 09/22/2011] [Indexed: 01/05/2023]
Abstract
This communication reviews most of the important findings related to venom components isolated from scorpions and spiders, mainly by means of gene cloning and expression. Rather than revising results obtained by classical biochemical studies that report structure and function of venom components, here the emphasis is placed on cloning and identification of genes present in the venomous glands of these arachnids. Aspects related to cDNA library construction, specific or random ESTs cloning, transcriptome analysis, high-throughput screening, heterologous expression and folding are briefly discussed, showing some numbers of species and components already identified, but also shortly mentioning limitations and perspectives of research for the future in this field.
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Affiliation(s)
- V Quintero-Hernández
- Instituto de Biotecnología - UNAM, Avenida Universidad, Colonia Chamilpa, Cuernavaca, Morelos, Mexico
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Estrada G, Restano-Cassulini R, Ortiz E, Possani LD, Corzo G. Addition of positive charges at the C-terminal peptide region of CssII, a mammalian scorpion peptide toxin, improves its affinity for sodium channels Nav1.6. Peptides 2011; 32:75-9. [PMID: 21078353 DOI: 10.1016/j.peptides.2010.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/28/2010] [Accepted: 11/01/2010] [Indexed: 11/25/2022]
Abstract
CssII is a β-scorpion peptide that modifies preferentially sodium currents of the voltage-dependent Na(+) channel (Nav) sub-type 1.6. Previously, we have found that the C-terminal amidation of CssII increases its affinity for Nav, which opens at more negative potentials in the presence of CssII. Although C-terminal amidation in vitro conditions is possible, five CssII peptide toxin variants with C-terminal residues modified were heterologously expressed (rN66S, rN66H, rN66R, r[T64R/N66S] and r[T64R/N66R], in which r stands for recombinant, the capital letters to the amino acid residues and the numbers indicate the position of the given residue into the primary sequence of the toxin) and correctly folded. A secondary structure prediction of CssII agrees with the experimental secondary structure obtained by circular dichroism; so all bacterial expressed neurotoxin variants maintained the typical α/β secondary structure motif of most Na(+) channel scorpion toxins. The electrophysiological properties of all recombinant variants were examined, and it was found that substitutions of threonine (T) and asparagine (N) at the C-terminal region for arginine (R) (r[T64R/N66R]) increase their affinity for Nav1.6. Although, the molecular interactions involved in this mechanism are still not clearly determined, there is experimental evidence supporting the suspicion that incorporation of basic charged amino acid residues at the C-terminal tail of a group of α-scorpion toxin was favored by natural selection.
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Affiliation(s)
- Georgina Estrada
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Av. Universidad 2001, Apartado Postal 510-3, Cuernavaca, Morelos 61500, Mexico
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27
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Cui Y, Guo GL, Ma L, Hu N, Song YB, Liu YF, Wu CF, Zhang JH. Structure and function relationship of toxin from Chinese scorpion Buthus martensii Karsch (BmKAGAP): gaining insight into related sites of analgesic activity. Peptides 2010; 31:995-1000. [PMID: 20307602 DOI: 10.1016/j.peptides.2010.03.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/09/2010] [Accepted: 03/09/2010] [Indexed: 10/19/2022]
Abstract
In this study, an effective Escherichia coli expression system was used to study the role of residues in the antitumor-analgesic peptide from Chinese scorpion Buthus martensii Karsch (BmKAGAP). To evaluate the extent to which residues of the toxin core contribute to its analgesic activity, nine mutants of BmKAGAP were obtained by PCR. Using site-directed mutagenesis, all of these residues were individually substituted by one amino acid. These were then subjected to a circular dichroism analysis, and an analgesic activity assay in mice. This study represents a thorough mapping and elucidation of the epitopes that underlie the molecular basis of the analgesic activity. The three-dimensional structure of BmKAGAP was established by homology modeling. Our results revealed large mutant-dependent differences that indicated important roles for the studied residues. With our ongoing efforts for establishing the structure and analgesic activity relationship of BmKAGAP, we have succeeded in pinpointing which residues are important for the analgesic activity.
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Affiliation(s)
- Yong Cui
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning Province 110016, PR China
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28
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Heterologous expressed toxic and non-toxic peptide variants of toxin CssII are capable to produce neutralizing antibodies against the venom of the scorpion Centruroides suffusus suffusus. Immunol Lett 2009; 125:93-9. [DOI: 10.1016/j.imlet.2009.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/20/2009] [Accepted: 06/03/2009] [Indexed: 11/21/2022]
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[Effects of Buthus occitanus tunetanus envenomation on an experimental murine model of gestation]. C R Biol 2007; 330:890-6. [PMID: 18068647 DOI: 10.1016/j.crvi.2007.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 09/03/2007] [Accepted: 09/05/2007] [Indexed: 11/23/2022]
Abstract
Scorpion envenoming is less studied in pregnant victims. In this work, the effect of Buthus occitanus tunetanus on parturition in late pregnancy was studied in an animal model. Four groups of six primigravid female rats, each one at the 22nd day of pregnancy, were used. The first two groups had received an intra-peritoneal injection of 500 microg/kg of Buthus occitanus tunetanus crude venom or a physiological saline solution and left until foetal delivery. Then, the time elapsed until the first pup delivery and that separating the first and latest ones were measured. The other two groups served for the uterine electrophysiological activity exploration. Rats were anaesthetized, artificially ventilated and had received an intraperitoneal injection of 500 microg/kg of Buthus occitanus tunetanus crude venom or a physiological saline solution. Our results showed a significant increase of the latency to foetal delivery, labour time, and uterine contractile activity in envenomed rats compared to controls. Such signs are usually seen in dynamic dystocia. It was concluded that Buthus occitanus tunetanus envenoming might induce a dynamic dystocia, when it occurred in late pregnancy.
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30
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Estrada G, Garcia BI, Schiavon E, Ortiz E, Cestele S, Wanke E, Possani LD, Corzo G. Four disulfide-bridged scorpion beta neurotoxin CssII: Heterologous expression and proper folding in vitro. Biochim Biophys Acta Gen Subj 2007; 1770:1161-8. [PMID: 17544584 DOI: 10.1016/j.bbagen.2007.04.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 03/29/2007] [Accepted: 04/20/2007] [Indexed: 11/30/2022]
Abstract
The gene of the four disulfide-bridged Centruroides suffusus suffusus toxin II was cloned into the expression vector pQE30 containing a 6His-tag and a FXa proteolytic cleavage region. This recombinant vector was transfected into Escherichia coli BL21 cells and expressed under induction with isopropyl thiogalactoside (IPTG). The level of expression was 24.6 mg/l of culture medium, and the His tagged recombinant toxin (HisrCssII) was found exclusively in inclusion bodies. After solubilization the HisrCssII peptide was purified by affinity and hydrophobic interaction chromatography. The reverse-phase HPLC profile of the HisrCssII product obtained from the affinity chromatography step showed several peptide fractions having the same molecular mass of 9392.6 Da, indicating that HisrCssII was oxidized forming several distinct disulfide bridge arrangements. The multiple forms of HisrCssII after reduction eluted from the column as a single protein component of 9400.6 Da. Similarly, an in vitro folding of the reduced HisrCssII generated a single oxidized component of HisrCssII, which was cleaved by the proteolytic enzyme FXa to the recombinant CssII (rCssII). The molecular mass of rCssII was 7538.6 Da as expected. Since native CssII (nCssII) is amidated at the C-terminal residue whereas the rCssII is heterologously expressed in the format of free carboxyl end, there is a difference of 1 Da, when comparing both peptides (native versus heterologously expressed). Nevertheless, they show similar toxicity when injected intracranially into mice, and both nCssII and rCssII show the typical electrophysiological properties of beta-toxins in Na(v)1.6 channels, which is for the first time demonstrated here. Binding and displacement experiments conducted with radiolabelled CssII confirms the electrophysiological results. Several problems associated with the heterologously expressed toxins containing four disulfide bridges are discussed.
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Affiliation(s)
- Georgina Estrada
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM. Apartado Postal 510-3, Cuernavaca Morelos, 62250, Mexico
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31
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Abstract
Voltage-gated Na(+) channels are integral membrane proteins that function as a gateway for a selective permeation of sodium ions across biological membranes. In this way, they are crucial players for the generation of action potentials in excitable cells. Voltage-gated Na(+) channels are encoded by at least nine genes in mammals. The different isoforms have remarkably similar functional properties, but small changes in function and pharmacology are biologically well-defined, as underscored by mutations that cause several diseases and by modulation of a myriad of compounds, respectively. This review will stress on the modulation of voltage-gated Na(+) channels by scorpion alpha-toxins. Nature has designed these two classes of molecules as if they were predestined to each other: an inevitable 'encounter' between a voltage-gated Na(+) channel isoform and an alpha-toxin from scorpion venom indeed results in a dramatically changed Na(+) current phenotype with clear-cut consequences on electrical excitability and sometimes life or death. This fascinating aspect justifies an overview on scorpion venoms, their alpha-toxins and the Na(+) channel targets they are built for, as well as on the molecular determinants that govern the selectivity and affinity of this 'inseparable duo'.
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Affiliation(s)
- Frank Bosmans
- Laboratory of Toxicology, University of Leuven, O and N 2, Postbus 922, Herestraat 49, 3000 Leuven, Belgium
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Bel Haj Rhouma R, Cérutti-Duonor M, Benkhadir K, Goudey-Perrière F, El Ayeb M, Lopez-Ferber M, Karoui H. Insecticidal effects of Buthus occitanus tunetanus BotIT6 toxin expressed in Escherichia coli and baculovirus/insect cells. JOURNAL OF INSECT PHYSIOLOGY 2005; 51:1376-83. [PMID: 16216259 DOI: 10.1016/j.jinsphys.2005.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 08/24/2005] [Accepted: 08/26/2005] [Indexed: 05/04/2023]
Abstract
BotIT6 is a neurotoxin polypeptide derived from the venom of the scorpion Buthus occitanus tunetanus (Bot). Its mature form is composed of 62 amino acids. BotIT6 has been reported to be the most potent toxin from Bot venom that has a strict selectivity for insects. Such toxin may have potential as a potent animal-harmless tool against insects. Using RT-PCR, we isolated and sequenced a cDNA encoding 62 amino acid residues corresponding to the known amino acid sequence of BotIT6. We have expressed a recombinant active form of BotIT6 in significantly high amounts in Escherichia coli. We have also engineered the cDNA into the Autographa californica Nuclear Polyhedrosis Virus (AcMNPV) genome and expressed the protein under control of the polyhedrin promoter. Supernatants of AcIT6-virus infected Sf9 insect cells exhibit a typical intoxication effect when injected to Spodoptera littoralis larvae. Moreover, injection of the recombinant virus showed enhanced insecticidal potency against S. littoralis larvae compared with wild type AcMNPV.
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Affiliation(s)
- Rahima Bel Haj Rhouma
- Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, Tunis-Belvedère, Tunisia
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Ali SA, Wang B, Alam M, Beck A, Stoeva S, Voelter W, Abbasi A, Duszenko M. Structure-activity relationship of an alpha-toxin Bs-Tx28 from scorpion (Buthus sindicus) venom suggests a new alpha-toxin subfamily. Arch Biochem Biophys 2005; 445:81-94. [PMID: 16309623 DOI: 10.1016/j.abb.2005.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/14/2005] [Accepted: 10/14/2005] [Indexed: 11/18/2022]
Abstract
Scorpion venoms are among the most widely known source of peptidyl neurotoxins used for callipering different ion channels, e.g., for Na(+), K(+), Ca(+) or Cl(-). An alpha-toxin (Bs-Tx28) has been purified from the venom of scorpion Buthus sindicus, a common yellow scorpion of Sindh, Pakistan. The primary structure of Bs-Tx28 was established using a combination of MALDI-TOF-MS, LC-ESI-MS, and automated Edman degradation analysis. Bs-Tx28 consists of 65 amino acid residues (7274.3+/-2Da), including eight cysteine residues, and shows very high sequence identity (82-94%) with other long-chain alpha-neurotoxins, active against receptor site-3 of mammalian (e.g., Lqq-IV and Lqh-IV from scorpions Leiurus sp.) and insect (e.g., BJalpha-IT and Od-1 from Buthotus judaicus and Odonthobuthus doriae, respectively) voltage-gated Na(+) channels. Multiple sequence alignment and phylogenetic analysis of Bs-Tx28 with other known alpha- and alpha-like toxins suggests the presence of a new and separate subfamily of scorpion alpha-toxins. Bs-Tx28 which is weakly active in both, mammals and insects (LD(50) 0.088 and 14.3microg/g, respectively), shows strong induction of the rat afferent nerve discharge in a dose-dependent fashion (EC(50)=0.01microg/mL) which was completely abolished in the presence of tetrodotoxin suggesting the binding of Bs-Tx28 to the TTX-sensitive Na(+)-channel. Three-dimensional structural features of Bs-Tx28, established by homology modeling, were compared with other known classical alpha-mammal (AaH-II), alpha-insect (Lqh-alphaIT), and alpha-like (BmK-M4) toxins and revealed subtle variations in the Nt-, Core-, and RT-CT-domains (functional domains) which constitute a "necklace-like" structure differing significantly in all alpha-toxin subfamilies. On the other hand, a high level of conservation has been observed in the conserved hydrophobic surface with the only substitution of W43 (Y43/42) and an additional hydrophobic character at position F40 (L40/A/V/G39), as compared to the other mentioned alpha-toxins. Despite major differences within the primary structure and activities of Bs-Tx28, it shares a common structural and functional motif (e.g., transRT-farCT) within the RT-CT domain which is characteristic of scorpion alpha-mammal toxins.
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Affiliation(s)
- Syed Abid Ali
- International Center for Chemical Sciences, HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270, Pakistan.
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Rodríguez de la Vega RC, Possani LD. Overview of scorpion toxins specific for Na+ channels and related peptides: biodiversity, structure-function relationships and evolution. Toxicon 2005; 46:831-44. [PMID: 16274721 DOI: 10.1016/j.toxicon.2005.09.006] [Citation(s) in RCA: 260] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Scorpion venoms contain a large number of bioactive components. Several of the long-chain peptides were shown to be responsible for neurotoxic effects, due to their ability to recognize Na(+) channels and to cause impairment of channel functions. Here, we revisited the basic paradigms in the study of these peptides in the light of recent data concerning their structure-function relationships, their functional divergence and extant biodiversity. The reviewed topics include: the criteria for classification of long-chain peptides according to their function, and a revision of the state-of-the-art knowledge concerning the surface areas of contact of these peptides with known Na(+) channels. Additionally, we compiled a comprehensive list encompassing 191 different amino acid sequences from long-chain peptides purified from scorpion venoms. With this dataset, a phylogenetic tree was constructed and discussed taking into consideration their documented functional divergence. A critical view on problems associated with the study of these scorpion peptides is presented, drawing special attention to the points that need revision and to the subjects under intensive research at this moment, regarding scorpion toxins specific for Na(+) channels and the other related long-chain peptides recently described.
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Affiliation(s)
- Ricardo C Rodríguez de la Vega
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Av. Universidad 2001, Apartado Postal 510-3, Cuernavaca Morelos 62210, Mexico
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Ye X, Bosmans F, Li C, Zhang Y, Wang DC, Tytgat J. Structural basis for the voltage-gated Na+ channel selectivity of the scorpion alpha-like toxin BmK M1. J Mol Biol 2005; 353:788-803. [PMID: 16209876 DOI: 10.1016/j.jmb.2005.08.068] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 08/26/2005] [Accepted: 08/26/2005] [Indexed: 11/21/2022]
Abstract
Scorpion alpha-like toxins are proteins that act on mammalian and insect voltage-gated Na+ channels. Therefore, these toxins constitute an excellent target for examining the foundations that underlie their target specificity. With this motive we dissected the role of six critical amino acids located in the five-residue reverse turn (RT) and C-tail (CT) of the scorpion alpha-like toxin BmK M1. These residues were individually substituted resulting in 11 mutants and were subjected to a bioassay on mice, an electrophysiological characterization on three cloned voltage-gated Na+ channels (Nav1.2, Nav1.5 and para), a CD analysis and X-ray crystallography. The results reveal two molecular sites, a couplet of residues (8-9) in the RT and a hydrophobic surface consisting of residues 57 and 59-61 in the CT, where the substitution with specific residues can redirect the alpha-like characteristics of BmK M1 to either total insect or much higher mammal specificity. Crystal structures reveal that the pharmacological ramification of these mutants is accompanied by the reshaping of the 3D structure surrounding position 8. Furthermore, our results also reveal that residues 57 and 59-61, located at the CT, enclose the critical residue 58 in order to form a hydrophobic "gasket". Mutants of BmK M1 that interrupt this hydrophobic surface significantly gain insect selectivity.
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Affiliation(s)
- Xiang Ye
- Center for Structural and Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People's Republic of China
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36
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Legros C, Céard B, Vacher H, Marchot P, Bougis PE, Martin-Eauclaire MF. Expression of the standard scorpion alpha-toxin AaH II and AaH II mutants leading to the identification of some key bioactive elements. Biochim Biophys Acta Gen Subj 2005; 1723:91-9. [PMID: 15725394 DOI: 10.1016/j.bbagen.2005.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2004] [Revised: 01/12/2005] [Accepted: 01/13/2005] [Indexed: 10/25/2022]
Abstract
The AaH II toxin from the scorpion Androctonus australis Hector is considered to be the standard alpha-toxin because it selectively binds with the highest known affinity to site 3 of mammalian voltage-activated Na+ channels (Na(v)) on rat brain synaptosomes but does not bind to insect synaptosomes. We generated two different constructs in pMALp allowing us to produce AaH II fused with the maltose-binding protein (MBP) in E. coli. We obtained reasonable amounts of recombinant AaH II after cleavage by enterokinase at the site DDDDK. We show that the introduction of a net negative charge at the C-terminus by the suppression of H64 amidation and the addition of an extra residue to the C-terminus (G65) led to fully active AaH II mutants, exhibiting exactly the same affinity as the native toxin for its target on rat brain synaptosomes. In contrast, the mutation of residue K58 into V, I or E residues drastically reduced toxin activity.
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Affiliation(s)
- Christian Legros
- Ingénierie des Protéines CNRS FRE 2738, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Secteur Nord, Université de la Méditerranée, Bd Pierre Dramard, 13916, Marseille, cedex 20, France
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