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Benazzouz SM, Benlouahmia N, Bouhadida K, Benlamara M, Arezki N, Sadeddine OEK, Issad M, Attal N, Mansouri K, Derrar F, Djidjik R. Evaluation of the immunoprotective power of a multiple antigenic peptide against Aah II toxin of Androctonus australis hector scorpion. Vaccine X 2024; 19:100503. [PMID: 38868522 PMCID: PMC11167365 DOI: 10.1016/j.jvacx.2024.100503] [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: 10/28/2023] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 06/14/2024] Open
Abstract
Scorpion envenoming (SE) is a public health problem in developing countries. In Algeria, the population exposed to the risk of SE was estimated at 86.45% in 2019. Thus, the development of a vaccine to protect the exposed population against scorpion toxins would be a major advance in the fight against this disease. This work aimed to evaluate the immunoprotective effect of a Multiple Antigenic Peptide against the Aah II toxin of Androctonus australis hector scorpion, the most dangerous scorpion species in Algeria. The immunogen MAP1Aah2 was designed and tested accordingly. This molecule contains a B epitope, derived from Aah II toxin, linked by a spacer to a universal T epitope, derived from the tetanus toxin. The results showed that MAP1Aah2 was non-toxic despite the fact that its sequence was derived from Aah II toxin. The immunoenzymatic assay revealed that the 3 immunization regimens tested generated specific anti-MAP1Aah2 antibodies and cross-reacted with the toxin. Mice immunized with this immunogen were partially protected against mortality caused by challenge doses of 2 and 3 LD50 of the toxin. The survival rate and developed symptoms varied depending on the adjuvant and the challenge dose used. In the in vitro neutralization test, the immune sera of mice having received the immunogen with incomplete Freund's adjuvant neutralized a challenge dose of 2 LD50. Hence, the concept of using peptide dendrimers, based on linear epitopes of scorpion toxins, as immunogens against the parent toxin was established. However, the protective properties of the tested immunogen require further optimizations.
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Affiliation(s)
- Safouane M. Benazzouz
- Laboratoire de Pharmacologie, Faculté de Pharmacie d’Alger, Université d’Alger 1. 8 Rue du Lieutenant Mohamed Benarfa, El Biar, Alger 16000, Algeria
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Nesrine Benlouahmia
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Karima Bouhadida
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Meriem Benlamara
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Naziha Arezki
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Oum El Kheir Sadeddine
- Laboratoire des Sérums Thérapeutiques, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Mourad Issad
- Laboratoire des Vaccins Viraux Humains, Département des Produits Biologiques Humains, Direction de la Production, Institut Pasteur d’Algérie, Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Nabila Attal
- Laboratoire d’Immunologie, Faculté de Pharmacie d’Alger, Université d’Alger 1. 8 Rue du Lieutenant Mohamed Benarfa, El Biar, Alger 16000, Algeria
- Département d’Immunologie, Direction des Laboratoires, de la Recherche et du Développement, Institut Pasteur d’Algérie, Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
| | - Kamel Mansouri
- Laboratoire de Pharmacologie, Faculté de Pharmacie d’Alger, Université d’Alger 1. 8 Rue du Lieutenant Mohamed Benarfa, El Biar, Alger 16000, Algeria
| | - Fawzi Derrar
- Laboratoire de la Grippe et autres Virus Respiratoires, Département de Virologie, Direction des Laboratoires, de la Recherche et du Développement, Institut Pasteur d’Algérie. Rue du Petit Staoueli, Dely Ibrahim, Alger 16320, Algeria
- Laboratoire de Microbiologie, Faculté de Médecine d’Alger, Université d’Alger 1. 8 Rue du Lieutenant Mohamed Benarfa, El Biar, Alger 16000, Algeria
| | - Reda Djidjik
- Laboratoire d’Immunologie, Faculté de Pharmacie d’Alger, Université d’Alger 1. 8 Rue du Lieutenant Mohamed Benarfa, El Biar, Alger 16000, Algeria
- Laboratoire d’Immunologie Médicale, CHU Issaad Hassani, Rue Ibrahim Hadjeras, Beni Messous, Alger 16206, Algeria
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Boussag-Abib L, Laraba-Djebari F. Long-term antibody response and protective effect induced by attenuated scorpion toxins: Involvement of memory plasma cells. Immunobiology 2021; 226:152108. [PMID: 34247017 DOI: 10.1016/j.imbio.2021.152108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/21/2021] [Accepted: 05/29/2021] [Indexed: 10/20/2022]
Abstract
In Algeria, Androctonus australis hector scorpion envenomation remains a major problem of public health because of non-efficient therapy. The development of safe vaccine against scorpion venom could be one key strategy for the envenomation prevention. The irradiation of venom by γ-rays develops suitable immunogens which produced effective antivenom and safe vaccine. In this study, we investigated the ability of the irradiated toxic fraction (γ-FtoxG50) to induce long-term memory humoral response in immunized animals (mice and rabbits), by involving the long-lived plasma cells to prevent efficiently the lethality of scorpion envenomation. For this purpose, an appropriate immunization schedule was established in mice and rabbits using three (3) similar doses of γ-FtoxG50 associated with Alum adjuvant. Obtained results indicate that the long-term immunogenicity of γ-FtoxG50 is able to induce the long-term memory humoral response with a high level of specific antibodies. The long-term persistence of antibody levels could depend on bone marrow memory plasma cells. These cells produce continuously antibodies without antigen stimulus. Furthermore, an enhanced memory response was obtained post-repeated envenomation with toxic native venom that leads to improved protection of animals. Together, pre-existing protective antibodies and the activation of memory B-cells could induce a rapid neutralization of scorpion toxins and long-term protection against scorpion envenomation.
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Affiliation(s)
- Lila Boussag-Abib
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32 El-Alia, Bab Ezzouar, Algiers, Algeria
| | - Fatima Laraba-Djebari
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32 El-Alia, Bab Ezzouar, Algiers, Algeria.
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Isolation and Characterization of Insecticidal Toxins from the Venom of the North African Scorpion, Buthacus leptochelys. Toxins (Basel) 2019; 11:toxins11040236. [PMID: 31027216 PMCID: PMC6521144 DOI: 10.3390/toxins11040236] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/16/2019] [Accepted: 04/22/2019] [Indexed: 11/17/2022] Open
Abstract
Various bioactive peptides have been identified in scorpion venom, but there are many scorpion species whose venom has not been investigated. In this study, we characterized venom components of the North African scorpion, Buthacus leptochelys, by mass spectrometric analysis and evaluated their insect toxicity. This is the first report of chemical and biological characterization of the B. leptochelys venom. LC/MS analysis detected at least 148 components in the venom. We isolated four peptides that show insect toxicity (Bl-1, Bl-2, Bl-3, and Bl-4) through bioassay-guided HPLC fractionation. These toxins were found to be similar to scorpion α- and β-toxins based on their N-terminal sequences. Among them, the complete primary structure of Bl-1 was determined by combination of Edman degradation and MS/MS analysis. Bl-1 is composed of 67 amino acid residues and crosslinked with four disulfide bonds. Since Bl-1 shares high sequence similarity with α-like toxins, it is likely that it acts on Na+ channels of both insects and mammals.
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Kuldyushev NA, Berkut AA, Peigneur S, Tytgat J, Grishin EV, Vassilevski AA. Design of sodium channel ligands with defined selectivity - a case study in scorpion alpha-toxins. FEBS Lett 2017; 591:3414-3420. [DOI: 10.1002/1873-3468.12839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Nikita A. Kuldyushev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
- Moscow Institute of Physics and Technology (State University); Russia
| | - Antonina A. Berkut
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
- Moscow Institute of Physics and Technology (State University); Russia
| | - Steve Peigneur
- Toxicology and Pharmacology; University of Leuven; Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology; University of Leuven; Belgium
| | - Eugene V. Grishin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
| | - Alexander A. Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry; Russian Academy of Sciences; Moscow Russia
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Ladjel-Mendil A, Martin-Eauclaire MF, Laraba-Djebari F. Neuro-Modulation of Immuno-Endocrine Response Induced by Kaliotoxin of Androctonus Scorpion Venom. J Biochem Mol Toxicol 2016; 30:580-587. [PMID: 27271987 DOI: 10.1002/jbt.21824] [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] [Received: 03/21/2016] [Revised: 05/18/2016] [Accepted: 05/23/2016] [Indexed: 12/16/2022]
Abstract
Kaliotoxin (KTX), a specific blocker of potassium channels, exerts various toxic effects due to its action on the central nervous system. Its use in experimental model could help the understanding of the cellular and molecular mechanisms involved in the neuropathological processes related to potassium channel dysfunctions. In this study, the ability of KTX to stimulate neuro-immuno-endocrine axis was investigated. As results, the intracerebroventricular injection of KTX leads to severe structural-functional alterations of both hypothalamus and thyroid. These alterations were characterized by a massive release of hormones' markers of thyroid function associated with damaged tissue which was infiltrated by inflammatory cell and an imbalanced redox status. Taken together, these data highlight that KTX is able to modulate the neuro-endocrine response after binding to its targets leading to the hypothalamus and the thyroid stimulation, probably by inflammatory response activation and the installation of oxidative stress in these organs.
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Affiliation(s)
- Amina Ladjel-Mendil
- USTHB, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, Algiers, Algeria
| | - Marie-France Martin-Eauclaire
- CNRS UMR 7286 CRN2M, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, Aix-Marseille University, Marseille, France
| | - Fatima Laraba-Djebari
- USTHB, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, Algiers, Algeria
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6
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Santibáñez-López CE, Francke OF, Ureta C, Possani LD. Scorpions from Mexico: From Species Diversity to Venom Complexity. Toxins (Basel) 2015; 8:E2. [PMID: 26712787 PMCID: PMC4728524 DOI: 10.3390/toxins8010002] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/25/2015] [Accepted: 12/09/2015] [Indexed: 12/13/2022] Open
Abstract
Scorpions are among the oldest terrestrial arthropods, which are distributed worldwide, except for Antarctica and some Pacific islands. Scorpion envenomation represents a public health problem in several parts of the world. Mexico harbors the highest diversity of scorpions in the world, including some of the world's medically important scorpion species. The systematics and diversity of Mexican scorpion fauna has not been revised in the past decade; and due to recent and exhaustive collection efforts as part of different ongoing major revisionary systematic projects, our understanding of this diversity has changed compared with previous assessments. Given the presence of several medically important scorpion species, the study of their venom in the country is also important. In the present contribution, the diversity of scorpion species in Mexico is revised and updated based on several new systematic contributions; 281 different species are recorded. Commentaries on recent venomic, ecological and behavioral studies of Mexican scorpions are also provided. A list containing the most important peptides identified from 16 different species is included. A graphical representation of the different types of components found in these venoms is also revised. A map with hotspots showing the current knowledge on scorpion distribution and areas explored in Mexico is also provided.
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Affiliation(s)
- Carlos E Santibáñez-López
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca Morelos 62210, Mexico.
| | - Oscar F Francke
- Colección Nacional de Arácnidos, Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, Copilco, Coyoacán A.P. 70-233, Distrito Federal 04510, Mexico.
| | - Carolina Ureta
- Laboratorio de Genética Molecular, Desarrollo y Evolución de Plantas, Departamento de Ecología Funcional, Instituto de Ecología, Universidad Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, Distrito Federal 04510, Mexico.
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca Morelos 62210, Mexico.
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Nunes KP, Torres FS, Borges MH, Matavel A, Pimenta AM, De Lima ME. New insights on arthropod toxins that potentiate erectile function. Toxicon 2013; 69:152-9. [DOI: 10.1016/j.toxicon.2013.03.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 02/21/2013] [Accepted: 03/22/2013] [Indexed: 12/19/2022]
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Abstract
Synopsis:The diversity of biological functions that are exerted by toxins from snake and scorpion venoms is associated with a limited number of structural frameworks. At present, one predominant basic fold has been observed among scorpion toxins whereas six folds have been found among snake toxins. Most toxin folds have the capacity to accept multiple insertions, deletions and mutations and to exert various recognition functions. We suggest that such folds may serve as guides to engineer new protein functions.
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Smith LA. Cloning, Characterization, and Expression of Animal Toxin Genes for Vaccine Development. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569549009033116] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Becerril B, Corona M, García C, Bolívar F, Possani LD. Cloning of Genes Encoding Scorpion Toxins: An Interpretative Review. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569549509019468] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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12
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Immunological characterization of a non-toxic peptide conferring protection against the toxic fraction (AahG50) of the Androctonus australis hector venom. Toxicon 2008; 51:353-62. [PMID: 18054371 DOI: 10.1016/j.toxicon.2007.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 09/01/2007] [Accepted: 10/16/2007] [Indexed: 11/20/2022]
Abstract
KAaH1 and KAaH2 are non-toxic peptides, isolated from the venom of the Androctonus australis hector (Aah) scorpion. In a previous study, we showed these peptides to be the most abundant (approximately 10% each) in the toxic fraction (AahG50) of the Aah venom. KAaH1 and KAaH2 showed high sequence identities (approximately 60%) with birtoxin-like peptides, which likewise are the major peptidic components of Parabuthus transvaalicus scorpion venom. Here, we report the immunological characterization of KAaH1 and KAaH2. These peptides were found to be specifically recognized by polyclonal antibodies raised against AahII, the most toxic peptide of Aah venom, and represents the second antigenic group, including toxins from different scorpion species in the world. Moreover, KAaH1 partially inhibits AahII binding to its specific antibody, suggesting some common epitopes between these two peptides. The identification of possible key antigenic residues in KAaH1 was deduced from comparison of its 3-D model with the experimental structure of AahII. Two clusters of putative antigenically important residues were found at the exposed surface; one could be constituted of V3 and D53, the other of D10, T15 and Y16. Polyclonal antibodies raised against KAaH1 in mice were found to cross-react with both AahII and AahG50, and neutralizing 5LD(50)/ml of the toxic fraction. Mice vaccinated with KAaH1 were protected against a challenge of 2LD(50) of AahG50 fraction. All these data suggest that KAaH1 has clear advantages over the use of the whole or part of the venom. KAaH1 is not toxic and could produce sera-neutralizing scorpion toxins, not only from Aah venom, but also toxins of other venoms from Buthus, Leiurus, or Parabuthus scorpion species presenting antigenically related toxins.
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Maertens C, Cuypers E, Amininasab M, Jalali A, Vatanpour H, Tytgat J. Potent Modulation of the Voltage-Gated Sodium Channel Nav1.7 by OD1, a Toxin from the Scorpion Odonthobuthus doriae. Mol Pharmacol 2006; 70:405-14. [PMID: 16641312 DOI: 10.1124/mol.106.022970] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels are essential for the propagation of action potentials in nociceptive neurons. Nav1.7 is found in peripheral sensory and sympathetic neurons and involved in short-term and inflammatory pain. Nav1.8 and Nav1.3 are major players in nociception and neuropathic pain, respectively. In our effort to identify isoform-specific and high-affinity ligands for these channels, we investigated the effects of OD1, a scorpion toxin isolated from the venom of the scorpion Odonthobuthus doriae. Nav1.3, Nav1.7, and Nav1.8 channels were coexpressed with beta1-subunits in Xenopus laevis oocytes. Na+ currents were recorded with the two-electrode voltage-clamp technique. OD1 modulates Nav1.7 at low nanomolar concentrations: 1) fast inactivation is dramatically impaired, with an EC50 value of 4.5 nM; 2) OD1 substantially increases the peak current at all voltages; and 3) OD1 induces a substantial persistent current. Nav1.8 was not affected by concentrations up to 2 microM, whereas Nav1.3 was sensitive only to concentrations higher than 100 nM. OD1 impairs the inactivation process of Nav1.3 with an EC50 value of 1127 nM. Finally, the effects of OD1 were compared with a classic alpha-toxin, AahII from Androctonus australis Hector and a classic alpha-like toxin, BmK M1 from Buthus martensii Karsch. At a concentration of 50 nM, both toxins affected Nav1.7. Nav1.3 was sensitive to AahII but not to BmK M1, whereas Nav1.8 was affected by neither toxin. In conclusion, the present study shows that the scorpion toxin OD1 is a potent modulator of Nav1.7, with a unique selectivity pattern.
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Affiliation(s)
- Chantal Maertens
- Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49 - Box 922, B-3000 Leuven, Belgium
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Srairi-Abid N, Guijarro JI, Benkhalifa R, Mantegazza M, Cheikh A, Ben Aissa M, Haumont PY, Delepierre M, El Ayeb M. A new type of scorpion Na+-channel-toxin-like polypeptide active on K+ channels. Biochem J 2005; 388:455-64. [PMID: 15656785 PMCID: PMC1138952 DOI: 10.1042/bj20041407] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have purified and characterized two peptides, named KAaH1 and KAaH2 (AaH polypeptides 1 and 2 active on K+ channels, where AaH stands for Androctonus australis Hector), from the venom of A. australis Hector scorpions. Their sequences contain 58 amino acids including six half-cysteines and differ only at positions 26 (Phe/Ser) and 29 (Lys/Gln). Although KAaH1 and KAaH2 show important sequence similarity with anti-mammal beta toxins specific for voltage-gated Na+ channels, only weak beta-like effects were observed when KAaH1 or KAaH2 (1 microM) were tested on brain Nav1.2 channels. In contrast, KAaH1 blocks Kv1.1 and Kv1.3 channels expressed in Xenopus oocytes with IC50 values of 5 and 50 nM respectively, whereas KAaH2 blocks only 20% of the current on Kv1.1 and is not active on Kv1.3 channels at a 100 nM concentration. KAaH1 is thus the first member of a new subfamily of long-chain toxins mainly active on voltage-gated K+ channels. NMR spectra of KAaH1 and KAaH2 show good dispersion of signals but broad lines and poor quality. Self-diffusion NMR experiments indicate that lines are broadened due to a conformational exchange on the millisecond time scale. NMR and CD indicate that both polypeptides adopt a similar fold with alpha-helical and b-sheet structures. Homology-based molecular models generated for KAaH1 and KAaH2 are in accordance with CD and NMR data. In the model of KAaH1, the functionally important residues Phe26 and Lys29 are close to each other and are located in the alpha-helix. These residues may constitute the so-called functional dyad observed for short alpha-KTx scorpion toxins in the beta-sheet.
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Affiliation(s)
- Najet Srairi-Abid
- Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13, place Pasteur, BP-74 Tunis 1002, Tunisia.
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M'Barek S, Fajloun Z, Cestèle S, Devaux C, Mansuelle P, Mosbah A, Jouirou B, Mantegazza M, Van Rietschoten J, El Ayeb M, Rochat H, Sabatier JM, Sampieri F. First chemical synthesis of a scorpion α-toxin affecting sodium channels: The Aah I toxin ofAndroctonus australis hector. J Pept Sci 2004; 10:666-77. [PMID: 15568681 DOI: 10.1002/psc.582] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aah I is a 63-residue alpha-toxin isolated from the venom of the Buthidae scorpion Androctonus australis hector, which is considered to be the most dangerous species. We report here the first chemical synthesis of Aah I by the solid-phase method, using a Fmoc strategy. The synthetic toxin I (sAah I) was renatured in DMSO-Tris buffer, purified and subjected to thorough analysis and comparison with the natural toxin. The sAah I showed physico-chemical (CD spectrum, molecular mass, HPLC elution), biochemical (amino-acid composition, sequence), immunochemical and pharmacological properties similar to those of the natural toxin. The synthetic toxin was recognized by a conformation-dependent monoclonal anti-Aah I antibody, with an IC50 value close to that for the natural toxin. Following intracerebroventricular injection, the synthetic and the natural toxins were similarly lethal to mice. In voltage-clamp experiments, Na(v) 1.2 sodium channel inactivation was inhibited by the application of sAah I or of the natural toxin in a similar way. This work describes a simple protocol for the chemical synthesis of a scorpion alpha-toxin, making it possible to produce structural analogues in time.
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Affiliation(s)
- Sarrah M'Barek
- FRE 2738 CNRS-Université de la Méditerranée, Laboratoire de Biochimie and Laboratoire International Associé d'lngénierie Biomoleculaire, IFR Jean Roche, Faculté de Médecine Nord, Bd Pierre Dramard, 13916 Marseille, France
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Wang CG, Gilles N, Hamon A, Le Gall F, Stankiewicz M, Pelhate M, Xiong YM, Wang DC, Chi CW. Exploration of the functional site of a scorpion alpha-like toxin by site-directed mutagenesis. Biochemistry 2003; 42:4699-708. [PMID: 12705833 DOI: 10.1021/bi0270438] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Scorpion alpha-neurotoxins can be classified into distinct subgroups according to their sequence and pharmacological properties. Using toxicity tests, binding studies, and electrophysiological recordings, BmK M1, a toxin from the Asian scorpion Buthus martensi Karsch, was experimentally identified as an alpha-like toxin. Being the first alpha-like toxin available in a recombinant form, BmK M1 was then modified by site-directed mutagenesis for investigation of the molecular basis of its activity. The results suggested a functional site which protrudes from the molecular scaffold as a unique tertiary arrangement, constituted by the five-residue reverse turn 8-12 and the C-terminal segment. The C-terminal basic residues Lys62 and His64 together with Lys8 in the turn, which are critical for the bioactivities, may directly interact with the receptor site on the sodium channel. Residues Asn11 and Arg58, indispensable for the activities, are mainly responsible for stabilizing the distinct conformation of the putative bioactive site. Among others, His10 and His64 seem to be involved in the preference of BmK M1 for phylogenetically distinct target sites. The comparison of BmK M1 with Aah2 (classical alpha-toxin) and Lqh(alpha)IT (alpha-insect toxin) showed that the specific orientation of the C-terminus mediated by the reverse turn might be relevant to the preference of alpha-toxin subgroups for phylogenetically distinct yet closely related receptor sites. The Y5G mutation indicated the "conserved hydrophobic surface" might be structurally important for stabilizing the beta-sheet in the alpha/beta-scaffold. The observations in this work shed light on the nature and roles of the residues possibly involved in the biological activity of a scorpion alpha-like toxin.
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Affiliation(s)
- Chun-Guang Wang
- Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Yue-Yang Road 320, Shanghai 200031, China
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17
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Wang CG, Ling MH, Chi CW, Wang DC, Pelhate M. Purification of two depressant insect neurotoxins and their gene cloning from the scorpion Buthus martensi Karsch. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2003; 61:7-16. [PMID: 12472844 DOI: 10.1034/j.1399-3011.2003.21020.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Insect-specific neurotoxins are important components of scorpion venoms. In this study, two toxins from the scorpion Buthus martensi Karsch (BmK) were purified. They shared high sequence homology with other depressant insect toxins and were designated BmK ITa and BmK ITb, respectively. They were able to suppress the action potential of cockroach isolated axon, which is due to a decrease in the peak sodium current. Furthermore, the effect of BmK ITb was lower than that of BmK ITa, and some of the electrophysiological characteristics of BmK ITb even resemble that of excitatory insect toxins. Their primary structures were determined by N-terminal partial sequence determination and cDNA cloning. The differences in their structures, especially the 31st residues, may result in the unique activity of BmK ITb.
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Affiliation(s)
- C-G Wang
- Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China
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18
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Kopeyan C, Martinez G, Rochat H. Primary structure of toxin IV of Leiurus quinquestriatus quinquestriatus. FEBS Lett 2001. [DOI: 10.1016/0014-5793(85)80262-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Ye JG, Chen J, Zuo XP, Ji YH. Cloning and characterization of cDNA sequences encoding two novel alpha-like-toxin precursors from the Chinese scorpion Buthus martensii Karsch. Toxicon 2001; 39:1191-4. [PMID: 11306129 DOI: 10.1016/s0041-0101(00)00257-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
According to a relative conserved fragment of alpha-scorpion toxins, a degenerate primer was designed and synthesized. Two full-length cDNAs encoding the precursors of two novel putative alpha-like-toxins were then amplified from the total cDNAs of venomous glands of the Chinese scorpion Buthusmartensi Karsch using 3' and 5' RACE (rapid amplification of cDNA ends). The precursors were both composed of 85 amino acid residues, including a putative signal peptide of 19 residues and a mature toxin of 66 residues, respectively. The predicted amino acid sequences of these two toxins show a homology of 82% with each other, and of 55-70% with other BmK-originated alpha-like-toxins. Interestingly, it is rarely seen in other alpha or alpha-like-toxins that: (1) Met residue but not a basic amino acid residue (Arg or Lys) is located on position 58 for BmKalpha2; (2) both toxins are ended with double Gly in the C-terminus.
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Affiliation(s)
- J G Ye
- Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, People's Republic of, Shanghai, China
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20
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Goudet C, Huys I, Clynen E, Schoofs L, Wang DC, Waelkens E, Tytgat J. Electrophysiological characterization of BmK M1, an alpha-like toxin from Buthus martensi Karsch venom. FEBS Lett 2001; 495:61-5. [PMID: 11322948 DOI: 10.1016/s0014-5793(01)02365-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study investigates the electrophysiological actions of BmK M1, an alpha-like toxin purified from the venom of the scorpion Buthus martensi Karsch, on voltage-gated Na+ channels. Using the voltage clamp technique, we assessed the BmK M1 activity on the cardiac Na+ channel (hH1) functionally expressed in Xenopus oocytes. The main actions of the toxin are a concentration-dependent slowing of the inactivation process and a hyperpolarizing shift of the steady-state inactivation. This work is the first electrophysiological characterization of BmK M1 on a cloned Na+ channel, demonstrating that this toxin belongs to the class of scorpion alpha-toxins. Our results also show that BmK M1 can be considered as a cardiotoxin.
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Affiliation(s)
- C Goudet
- Laboratory of Toxicology, University of Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium
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21
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Srairi-Abid N, Mansuelle P, Mejri T, Karoui H, Rochat H, Sampieri F, El Ayeb M. Purification, characterization and molecular modelling of two toxin-like proteins from the Androctonus australis Hector venom. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5614-20. [PMID: 10951222 DOI: 10.1046/j.1432-1327.2000.01632.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two toxin-like proteins (AahTL1 and AahTL3) were purified from the venom of the scorpion Androctonus australis Hector (Aah). AahTL1 and AahTL3 are the first non toxic proteins cross-reacting with AahI toxins group which indicates that these proteins can be used as a model of vaccins. In order to study structure-function relationships, their complete amino-acid sequences (66 residues) were determined, by automated Edman degradation. They show more than 50% of similarity with both AahI and AahIII antimammal toxins. Three-dimensional structural models of AahTL1 and AahTL3 constructed by homology suggest that the two proteins are structurally similar to antimammal scorpion alpha-toxins specific to voltage dependent Na+ channels. The models showed also that amino-acid changes between potent Aah toxins and both AahTL1 and AahTL3 disrupt the electrostatic potential gradient at their surface preventing their interaction with the receptor, which may explain their non toxicity.
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Affiliation(s)
- N Srairi-Abid
- Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, Tunisia.
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22
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Hahin R, Chen Z, Reddy G. The isolation and characterization of a peptide that alters sodium channels from Buthus martensii Karsch. Toxicon 2000; 38:645-60. [PMID: 10673157 DOI: 10.1016/s0041-0101(99)00180-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The peptides were purified using gel filtration, ion exchange, FPLC, and HPLC chromatography and found to greatly prolong action potentials at nanomolar concentrations when applied to frog and mouse nerves. The N-terminal primary amino acid sequence of one of the peptides, BMK 16(5), was determined. The first 23 amino acids of BMK 16(5) were found to be: VKDGYIADDRNCPYFCGRNAYYD. The two cysteine residues in the sequence appeared as Edman sequence cycle blanks; however, they were assigned to be cysteines due to sequence similarity to other peptide toxins that bind to sodium channels and identification of the presence of cysteines obtained from single time point amino acid analysis. The MW of BMK 16(5) was determined by a Perkin Elmer API 300 LC/MS/MS to be 3,695. The amino acid residues of BMK 16(5) show strong similarity with the first 23 amino acid residues of a number of scorpion alpha neurotoxins. Unlike these neurotoxins, BMK 16(5) possesses a proline residue at position 13 which will likely make it fold in a unique way so as to bind to and alter sodium channels.
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Affiliation(s)
- R Hahin
- Biological Sciences, Northern Illinois University, DeKalb 60115, USA
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23
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He XL, Li HM, Zeng ZH, Liu XQ, Wang M, Wang DC. Crystal structures of two alpha-like scorpion toxins: non-proline cis peptide bonds and implications for new binding site selectivity on the sodium channel. J Mol Biol 1999; 292:125-35. [PMID: 10493862 DOI: 10.1006/jmbi.1999.3036] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The crystal structures of two group III alpha-like toxins from the scorpion Buthus martensii Karsch, BmK M1 and BmK M4, were determined at 1.7 A and 1.3 A resolution and refined to R factors of 0.169 and 0.166, respectively. The first high-resolution structures of the alpha-like scorpion toxin show some striking features compared with structures of the "classical" alpha-toxin. Firstly, a non-proline cis peptide bond between residues 9 and 10 unusually occurs in the five-member reverse turn 8-12. Secondly, the cis peptide 9-10 mediates the spatial relationship between the turn 8-12 and the C-terminal stretch 58-64 through a pair of main-chain hydrogen bonds between residues 10 and 64 to form a unique tertiary arrangement which features the special orientation of the terminal residues 62-64. Finally, in consequence of the peculiar orientation of the C-terminal residues, the functional groups of Arg58, which are crucial for the toxin-receptor interaction, are exposed and accessible in BmK M1 and M4 rather than buried as in the classical alpha-toxins. Sequence alignment and characteristics analysis suggested that the above structural features observed in BmK M1 and M4 occur in all group III alpha-like toxins. Recently, some group III alpha-like toxins were demonstrated to occupy a receptor site different from the classical alpha-toxin. Therefore, the distinct structural features of BmK M1 and M4 presented here may provide the structural basis for the newly recognized toxin-receptor binding site selectivity. Besides, the non-proline cis peptide bonds found in these two structures play a role in the formation of the structural characteristics and in keeping accurate positions of the functionally crucial residues. This manifested a way to achieve high levels of molecular specificity and atomic precision through the strained backbone geometry.
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Affiliation(s)
- X L He
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P.R. China
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24
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Possani LD, Becerril B, Delepierre M, Tytgat J. Scorpion toxins specific for Na+-channels. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 264:287-300. [PMID: 10491073 DOI: 10.1046/j.1432-1327.1999.00625.x] [Citation(s) in RCA: 477] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Na+-channel specific scorpion toxins are peptides of 60-76 amino acid residues in length, tightly bound by four disulfide bridges. The complete amino acid sequence of 85 distinct peptides are presently known. For some toxins, the three-dimensional structure has been solved by X-ray diffraction and NMR spectroscopy. A constant structural motif has been found in all of them, consisting of one or two short segments of alpha-helix plus a triple-stranded beta-sheet, connected by variable regions forming loops (turns). Physiological experiments have shown that these toxins are modifiers of the gating mechanism of the Na+-channel function, affecting either the inactivation (alpha-toxins) or the activation (beta-toxins) kinetics of the channels. Many functional variations of these peptides have been demonstrated, which include not only the classical alpha- and beta-types, but also the species specificity of their action. There are peptides that bind or affect the function of Na+-channels from different species (mammals, insects or crustaceans) or are toxic to more than one group of animals. Based on functional and structural features of the known toxins, a classification containing 10 different groups of toxins is proposed in this review. Attempts have been made to correlate the presence of certain amino acid residues or 'active sites' of these peptides with Na+-channel functions. Segments containing positively charged residues in special locations, such as the five-residue turn, the turn between the second and the third beta-strands, the C-terminal residues and a segment of the N-terminal region from residues 2-11, seems to be implicated in the activity of these toxins. However, the uncertainty, and the limited success obtained in the search for the site through which these peptides bind to the channels, are mainly due to the lack of an easy method for expression of cloned genes to produce a well-folded, active peptide. Many scorpion toxin coding genes have been obtained from cDNA libraries and from polymerase chain reactions using fragments of scorpion DNAs, as templates. The presence of an intron at the DNA level, situated in the middle of the signal peptide, has been demonstrated.
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Affiliation(s)
- L D Possani
- Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad 2001, Cuernavaca, Mexico.
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25
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Hassani O, Loew D, Van Dorsselaer A, Papandréou MJ, Sorokine O, Rochat H, Sampieri F, Mansuelle P. Aah VI, a novel, N-glycosylated anti-insect toxin from Androctonus australis hector scorpion venom: isolation, characterisation, and glycan structure determination. FEBS Lett 1999; 443:175-80. [PMID: 9989600 DOI: 10.1016/s0014-5793(98)01710-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Aah VI was isolated from the venom of the North African scorpion, Androctonus australis hector. It is the first glycosylated neurotoxin from scorpion venom to be described. It was not toxic to mice, when injected intracerebroventricularly at a dose of 1.2 microg per animal. However, it had typical activity in Blatella germanica cockroaches resulting in gradual paralysis and very low toxicity (LD50 = 8.5 microg/g of animal). It consists of 66 amino acid residues and is heterogeneously N-glycosylated at a single site, on asparagine 9, of the Asn-Gly-Thr sequence. The potential N-glycosylation site was deduced from automatic Edman degradation and amino acid analysis, and glycan heterogeneity was evidenced by ESMS. Determination of the N-glycan structures (dHex, Hex and HexNAc) was assessed by nanoESMS/MS with picomolar amounts of sample. Current knowledge of N-glycan structure and composition suggests that the glycan structures are derived from a common core.
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Affiliation(s)
- O Hassani
- UMR 6560, Université de la Méditerranée CNRS, Laboratoire de Biochimie, Ingénierie des Protéines, IFR Jean Roche, Faculté de Médicine Secteur Nord, Marseille, France
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26
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Nakagawa Y, Sadilek M, Lehmberg E, Herrmann R, Herrmann R, Moskowitz H, Lee YM, Thomas BA, Shimizu R, Kuroda M, Jones AD, Hammock BD. Rapid purification and molecular modeling of AaIT peptides from venom of Androctonus australis. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 1998; 38:53-65. [PMID: 9627406 DOI: 10.1002/(sici)1520-6327(1998)38:2<53::aid-arch1>3.0.co;2-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
As recombinant viruses expressing scorpion toxins are moving closer toward the market, it is important to obtain large amounts of pure toxin for biochemical characterization and the evaluation of biological activity in nontarget organisms. In the past, we purified a large amount of Androctonus australis anti-insect toxin (AaIT) present in the venom of A. australis with an analytical reversed-phase column by repeated runs of crude sample. We now report 20 times improved efficiency and speed of the purification by employing a preparative reversed-phase column. In just two consecutive HPLC steps, almost 1 mg of AaIT was obtained from 70 mg crude venom. Furthermore, additional AaIT was obtained from side fractions in a second HPLC run. Recently discovered insect selective toxin, AaIT5, was isolated simultaneously from the same venom batch. It shows different biological toxicity symptoms than the known excitatory and depressant insect toxins. AaIT5 gave 100% mortality with a dose of less than 1.3 micrograms against fourth-instar tobacco budworms Heliothis virescens 24 h after injection. During the purification process, we implemented mass spectrometry in addition to bioassays to monitor the presence of AaIT and AaIT5 in the HPLC fractions. Mass spectrometric screening can unambiguously follow the purification process and can greatly facilitate and expedite the downstream purification of AaIT and AaIT5 eliminating the number of bioassays required. Further, electrospray ionization was compared with matrix-assisted desorption/ionization and evaluated as a method of choice for mass spectrometric characterization of fractions from the venom purification for it provided higher mass accuracy and relative quantitation capability. Molecular models were built for AaIT5, excitatory toxin AaIT4, and depressant toxin LqhIT2. Three-dimensional structure of AaIT5 was compared with structures of the other two toxins, suggesting that AaIT5 is similar to depressant toxins.
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Affiliation(s)
- Y Nakagawa
- Department of Entomology, University of California, Davis 95616, USA
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27
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Devaux C, Clot-Faybesse O, Juin M, Mabrouk K, Sabatier JM, Rochat H. Monoclonal antibodies neutralizing the toxin II from Androctonus australis hector scorpion venom: usefulness of a synthetic, non-toxic analog. FEBS Lett 1997; 412:456-60. [PMID: 9276446 DOI: 10.1016/s0014-5793(97)00826-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Scorpion venom contains toxins that act on ion channels. Some are responsible for the noxious effects observed when people are stung by scorpions. The study of the neutralization of these molecules and the production of monoclonal antibodies (mAbs) should prove valuable. Toxin II from Androctonus australis hector scorpion (AahII) is one of the most potent toxins and has been well-characterized and studied. Producing mAbs against such molecules is often difficult due to their toxicity. We used a synthetic, non-toxic analog, (Abu)8-AahII, to obtain mAbs which recognize and neutralize the native toxin AahII. Sets of peptides spanning the entire sequence of AahII were assayed to identify the binding sites of the mAbs. The various mAbs recognized only the largest peptides (12-17 residues). They recognized peptides corresponding to different parts of the AahII sequence, suggesting that several regions of the (Abu)8-AahII sequence mimic AahII epitopes and then elicit mAbs directed against toxin.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Monoclonal/chemistry
- Binding Sites, Antibody
- Binding, Competitive/immunology
- Epitope Mapping
- Female
- Hybridomas/metabolism
- Injections, Intraperitoneal
- Injections, Intraventricular
- Injections, Subcutaneous
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Neurotoxins/chemical synthesis
- Neurotoxins/immunology
- Neurotoxins/toxicity
- Peptides/chemical synthesis
- Peptides/immunology
- Rats
- Reptilian Proteins
- Scorpion Venoms/chemical synthesis
- Scorpion Venoms/immunology
- Scorpion Venoms/toxicity
- Synaptosomes/immunology
- Synaptosomes/metabolism
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Affiliation(s)
- C Devaux
- CNRS UMR 6560, Laboratoire d'Ingénierie des Protéines, Faculté de Médecine-Nord, Marseille, France.
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28
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Nakagawa Y, Lee YM, Lehmberg E, Herrmann R, Herrmann R, Moskowitz H, Jones AD, Hammock BD. Anti-insect toxin 5 (AaIT5) from Androctonus australis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 246:496-501. [PMID: 9208943 DOI: 10.1111/j.1432-1033.1997.t01-1-00496.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An insect-selective scorpion toxin (AaIT5) was purified from the venom of the North African scorpion Androctonus australis, and its amino acid sequence was determined by a combination of automated Edman degradation, electrospray-ionization mass spectrometry, and sequence alignment. This insect toxin is very potent against the tobacco budworm, Heliothis virescens (100% lethal dose < 1.8 microg/100 mg body mass) and shows a distinct insect specificity and various symptoms. It is not toxic to mice after subcutaneous injection. The molecular mass of this toxin is 6882 Da and the amino acid sequence is similar to those of Androctonus australis anti-insect toxin 4 (AaIT4), Leiurus quinquestriatus depressant anti-insect toxins (LqhIT2, LqqIT2), and Buthotus judaicus depressant anti-insect toxin (BjIT2).
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Affiliation(s)
- Y Nakagawa
- Department of Entomology, University of California, Davis 95616, USA
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29
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Devaux C, Fourquet P, Granier C. A conserved sequence region of scorpion toxins rendered immunogenic induces broadly cross-reactive, neutralizing antibodies. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 242:727-35. [PMID: 9022703 DOI: 10.1111/j.1432-1033.1996.0727r.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Scorpion toxins constitute a family of proteins with a high degree of sequence diversity but a common mode of action. Neutralization of the toxic effects of scorpion stings by serotherapy is limited due to the various serotypes expressed by these proteins. We explored the possibility of raising antibodies to conserved parts of the toxins which could recognize several members of the family. We established the variability profile of a set of 25 scorpion toxin sequences, then evaluated systematically by peptide-scanning methods the antigenicity of one scorpion toxin. The most conserved regions were generally very poorly antigenic. One exception was the N-terminal region, which is both conserved and antigenic. Antibodies were raised in rabbits against an eight-residue synthetic peptide mimicking the N-terminal region. These peptide antibodies were cross-reactive with several scorpion toxins belonging to different serotypes and neutralized both the pharmacological effects (binding to rat brain synaptosomes) and the biological activity (toxicity in mice) of the parent toxin. The molecular model of the toxin indicates that antibody binding to residues 1-8 probably either masks some residue(s) of the N-terminus critical for the biological activity or overlaps with the epitope previously defined by neutralizing monoclonal antibody. These findings could open the way for new therapeutic strategies for the medical care of envenomations.
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Affiliation(s)
- C Devaux
- CNRS URA 1455, Laboratoire de Biochimie, IFR Jean Roche, Faculté de Médecine Nord, Marseille, France
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30
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Marangoni S, Toyama MH, Arantes EC, Giglio JR, da Silva CA, Carneiro EM, Gonçalves AA, Oliveira B. Amino acid sequence of TsTX-V, an alpha-toxin from Tityus serrulatus scorpion venom, and its effect on K+ permeability of beta-cells from isolated rat islets of Langerhans. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1243:309-14. [PMID: 7727504 DOI: 10.1016/0304-4165(94)00142-k] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Highly purified Tityustoxin V (TsTX-V), an alpha-toxin isolated from the venom of the Brazilian scorpion Tityus serrulatus, was obtained by ion exchange chromatography on carboxymethylcellulose-52. It was shown to be homogeneous by reverse phase high performance liquid chromatography, N-terminal sequencing (first 39 residues) of the reduced and alkylated protein and by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and tricine. Following enzymatic digestion, the complete amino acid sequence (64 residues) was determined. The sequence showed higher homology with the toxins from the venoms of the North African than with those of the North and South American scorpions. Using the rate of 86Rb+ release from depolarized rat pancreatic beta-cells as a measure of K+ permeability changes, TsTX-V (5.6 micrograms/ml) was found to increase by 2.0-2.4-fold the rate of marker outflow in the presence of 8.3 mM glucose. This effect was persistent and slowly reversible, showing similarity to that induced by 100 microM veratridine, an agent that increases the open period of Na+ channels, delaying their inactivation. It is suggested that, by extending the depolarized period, TsTX-V indirectly affects beta-cell voltage-dependent K+ channels, thus increasing K+ permeability.
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Affiliation(s)
- S Marangoni
- Departamento de Bioquímica, Universidade Estadual de Campinas, SP, Brazil
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31
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Devaux C, Juin M, Mansuelle P, Granier C. Fine molecular analysis of the antigenicity of the Androctonus australis hector scorpion neurotoxin II: a new antigenic epitope disclosed by the Pepscan method. Mol Immunol 1993; 30:1061-8. [PMID: 7690110 DOI: 10.1016/0161-5890(93)90152-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A set of 58 overlapping rod-bound peptides was used to map the antigenic reactivity pattern of a 64-residue neurotoxin (AaH II) from the venom of the scorpion Androctonus australis hector. Five anti-toxin rabbit antisera were assayed serially for their capacity to bind to each peptide in the set. Six regions of antigenic reactivity were thus identified (sequences: 1-8, 4-12, 27-35, 39-45, 52-58 and 55-61). When positioned on a 3-D model of the toxin, these regions appeared to correspond to either beta-turn or extended parts of the molecule. The antigenic regions revealed by this technique agree fairly well with those previously mapped on the same toxin by different methods. One discrepancy was, however, that the present study shows the N-terminus to be strongly reactive with anti-toxin antibodies. The antigenicity of this region was confirmed, since rabbit antibodies raised against a synthetic peptide mimicking the sequence 1-8 of the toxin were found to bind the toxin with high efficiency. A fine analysis of the recognition of this region was performed. Alanine-containing analogs of the sequence 1-7 and peptides mimicking the N-terminal of the four main toxins of AaH were probed with anti-toxin and anti-peptide antibodies. Lysine 2, aspartic acid 3 and glycine 4 were shown to be key residues in the recognition of the N-terminal region of the AaH II toxin by anti-toxin antibodies. In contrast, a loose specificity of recognition was shown by one anti-peptide serum which was, in addition, able to recognize the N-termini of all four AaH toxins.
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Affiliation(s)
- C Devaux
- Laboratoire de Biochimie, CNRS URA 1455, Faculté de Médecine Secteur Nord, Marseille, France
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32
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Ait-Amara D, Chavez-Olortegui C, Romi R, Mery J, Brugidou J, Albericio F, Devaux C, Granier C. Antibodies cross-reactive with the scorpion-toxin II from Androctonus australis Hector elicited in mice by a synthetic peptide. NATURAL TOXINS 1993; 1:255-62. [PMID: 8167944 DOI: 10.1002/nt.2620010410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
With the aim of developing active protection against the noxious effects provoked in humans by scorpion stings, the possibility of eliciting toxin reactive antibodies by immunization with a short peptide was assessed in mice. The amino acid sequence of residues 50 to 59 of Androctonus australis Hector toxin II was chosen, on the basis of previous results indicating that rabbit anti-(50-59) antibodies neutralize the biological effects of the parent toxin. The peptide was prepared by solid-phase synthesis procedures and used in different forms (free, linearly polymerized, coupled to KLH, coupled to a low-molecular weight B-lymphocyte activator) in order to immunize groups of non-congenic NMRI or congenic C57BL/6 mice. The reactivities of each serum with the peptide and with the toxin were assessed in ELISA. Strong reactivities with both the peptide (mean titer over 1:52,600) and the toxin (mean titer 1:800) were observed in all mice from the group that received the KLH-coupled peptide. However, mouse immune sera failed either to recognize the toxin in a liquid-phase radioimmunoassay or to neutralize the lethal effects of the toxin. The requirements, in terms of affinity and recognition of native conformation, for anti-peptide antibodies to display neutralizing properties are discussed.
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Affiliation(s)
- D Ait-Amara
- Laboratoire de Biochimie, CNRS 1455 Faculté de Médecine Secteur Nord, Marseille, France
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33
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Kopeyan C, Mansuelle P, Martin-Eauclaire MF, Rochat H, Miranda F. Characterization of toxin III of the scorpion Leiurus quinquestriatus quinquestriatus: a new type of alpha-toxin highly toxic both to mammals and insects. NATURAL TOXINS 1993; 1:308-12. [PMID: 8167952 DOI: 10.1002/nt.2620010510] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The primary structure of toxin III of Leiurus quinquestriatus quinquestriatus (Lqq III) was elucidated by automatic Edman degradation of the reduced and S-carboxymethylated protein and derived tryptic peptides. Like other scorpion toxins that are active on sodium channels, Lqq III, consisting of 64 amino acids, is a 7 kDa single-chain polypeptide crosslinked by four disulfide bridges. It belongs to the alpha-toxin group, as judged by competition experiments with 125I AaH II for binding to rat brain synaptosomes (K0.5 = 7 x 10(-7) M). Lqq III is the first alpha-toxin to be characterized that is highly toxic to mice [LD50 = 50 micrograms (7.1 nmol)/kg body wt], by subcutaneous injection, insects Blatella germanica [LD50 = 60 ng (8.5 pmol)/g body wt.] and Musca domestica [LD50 = 120 ng (17 pmol)/g body wt]. When tested via the intracerebroventricular route, the toxicity for mice [55 micrograms (8 nmol)/kg] was of the same order as that found by subcutaneous injection, indicating that Lqq III has a higher affinity for peripheral sodium channels that for those of the central nervous system. There are three differences between the sequences of Lqq III and Lqh alpha IT, an alpha-toxin isolated from the venom of Leiurus quinquestriatus hebraeus. These substitutions are found at positions 20, 24, and 64 (Ser-->Ala,Asp-->Glu and His-->Arg, respectively). Surprisingly Lqh alpha IT is only weakly active in mice [LD50 = 5 mg (0.7 mumol)/kg], while in insects its toxicity is similar to that of Lqq III [140 ng (20 pmol)/g body wt blowfly larvae]. These observations are relevant to the definition of scorpion toxin structure-activity relationships.
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Affiliation(s)
- C Kopeyan
- Laboratoire de Biochime, Centre National de la Recherche Scientifique URA 1455, Faculté de Médecine, Secteur Nord, Marseille, France
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34
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Zlotkin E, Gurevitz M, Fowler E, Adams ME. Depressant insect selective neurotoxins from scorpion venom: chemistry, action, and gene cloning. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 1993; 22:55-73. [PMID: 8431601 DOI: 10.1002/arch.940220107] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The present study examines the similarity in the symptoms and binding properties between the depressant and excitatory insect-selective neurotoxins, derived from scorpion venom. A comparison of their primary structures and neuromuscular effects is presented. A new depressant toxin (LqhIT2) was purified from the venom of the scorpion Leiurus quinquestriatus hebraeus. The effects of this toxin on a prepupal housefly neuromuscular preparation mimic its effects on the intact insect, i.e, a brief period of repetitive bursts of regular junction potentials (JPs) is followed by reduced amplitude JPs ending with a block of the neuromuscular transmission. "Loose" patch clamp recordings indicate that the repetitive activity has a presynaptic origin (the motor nerve) and resembles the effect of the excitatory toxin AaIT. The final synaptic block is supposed to be the end result of neuronal membrane depolarization. Such an effect is not caused by an excitatory toxin, which induces long "trains" of repetitive firing. The amino acid sequences of three depressant toxins were determined by automatic Edman degradation indicating a high degree of sequence homology. This conservation differs from those of other groups of scorpion toxins. The opposing pharmacological effects of depressant toxins are discussed in light of the above neuromuscular effects and sequence analysis. A genetic approach in the study of the structure-function relationships of the depressant toxins was initiated by isolating cDNA clones encoding the LqhIT2 and BjIT2 toxins. Their sequence analysis revealed the precursor form of these toxins: A 21 amino acid residue signal peptide followed by a 61 amino acid region of the mature toxin, and three additional amino acids at the carboxy terminus.
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Affiliation(s)
- E Zlotkin
- Institute of Life Sciences, Hebrew University, Jerusalem, Israel
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35
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Sauermann U, Meyermann R, Schluesener HJ. Cloning of a novel TGF-beta related cytokine, the vgr, from rat brain: cloning of and comparison to homologous human cytokines. J Neurosci Res 1992; 33:142-7. [PMID: 1453478 DOI: 10.1002/jnr.490330118] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Here we describe cloning of a TGF-beta related cytokine from a rat brain cDNA library. This novel cytokine, the vgr (vegetal related), is homologous to the vegetal (Vg1) gene of Xenopus (DL Weeks and DA Melton, Cell, 51:861-867, 1987). In rat brain mRNA a single 3.5 kb RNA could be detected by Northern blot analysis. Thus, this new cytokine is constitutively expressed in the central nervous system. A monoclonal antibody reactive with a synthetic peptide of vgr revealed a faint vgr-like immunoreactivity throughout the CNS, with more pronounced staining of hippocampal neurons, ependymal cells, cells of the choroid plexus, and hypophysis. Using the rat cDNA, two homologous human cytokine cDNAs encoding the human vgr and op-1 were cloned.
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Affiliation(s)
- U Sauermann
- Department of Neurology, University of Wuerzburg, Federal Republic of Germany
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36
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Yahi N, Devaux C, Mansuelle P, Defendini ML, Granier C. Monoclonal antibodies to toxin II from the scorpion Androctonus australis Hector: further characterization of epitope specificities and neutralizing capacities. Toxicon 1992; 30:723-31. [PMID: 1380740 DOI: 10.1016/0041-0101(92)90006-q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The epitope specificities of two previously prepared monoclonal antibodies (mAb) to the toxin II from Androctonus australis Hector were characterized. Neither mAb 4C1 nor mAb 3C5 was able to recognize any of the 58 overlapping synthetic heptapeptides which cover the whole sequence of toxin II. Thus, both mAbs probably recognize conformation-dependent epitopes at the surface of the toxin. Experiments were designed to check whether or not the two mAbs, or their Fab fragments, were able to bind simultaneously to the toxin. The results indicated that the epitopes recognized by the two antibodies are probably close together at the surface of the toxin, thus preventing the simultaneous binding of both mAbs to a single toxin molecule. Given the proximity of the two epitopes and the fact that mAb 4C1 is known to be a neutralizing antibody, the capacity of mAb 3C5 to inhibit the toxic effects of the toxin was re-evaluated in C57BL/6 mice. A clear, but weak, neutralizing effect was found, consistent with the low affinity binding of the mAb in the proximity of a neutralizing site of the toxin.
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Affiliation(s)
- N Yahi
- CNRS URA 1455, Laboratoire de Biochimie, Faculté de Médecine Secteur Nord, Marseille, France
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37
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Abstract
In the three-dimensional architecture of macromolecules, the structural stability and proper folding manifest due to cooperative packing interaction of various segments. Hydrophobicity is the major factor stabilizing protein-protein associations. In the disulfide-containing proteins, S-S bonds are integral part of structural motifs and large part of the protein-folding problem can be reduced to identifying and understanding motifs and subdomains of these proteins. Identifying such a motif with S-S bonds in 'scorpion-toxin' type proteins, and from model-building studies, five tertiary structural models for these type of proteins can be proposed. These canonical structural models can be refined by regular minimum energy and computer simulation methods to arrive at the final tertiary structures. Such 'models' can be of considerable use i) in understanding the biochemical reaction mechanisms in the structure-function relationships, ii) structure determination by X-ray methods (molecular replacement method), iii) drug design etc.
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Affiliation(s)
- P Narayanan
- Department of Life Sciences, University of Bombay, India
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38
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Mansuelle P, Martin MF, Rochat H, Granier C. The amino acid sequence of toxin IV from theAndroctonus australis scorpion: Differing effects of natural mutations in scorpion α-toxins on their antigenic and toxic properties. ACTA ACUST UNITED AC 1992; 1:61-9. [PMID: 1344902 DOI: 10.1002/nt.2620010112] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The complete amino acid sequence (64 residues) of the AaH IV toxin from the scorpion Androctonus australis Hector was determined by automated Edman degradation and was compared with the sequences of other Androctonus toxins. AaH IV was also tested by radioimmunoassay for binding to antisera raised against other toxins of the same species. The results indicated that AaH IV shares some of the antigenic properties of AaH I and AaH III toxins, but does not cross-react with anti-AaH II antibodies. The structural basis for the observed antigenic relationships can be found in the high degree of homology displayed by AaH IV with regard to AaH I and III, the changes in amino acid residues equally affecting regions included or excluded from the main predicted antigenic sites of AaH IV. The lower biological potency of AaH IV is presumably the result of some of the sequence differences. In particular, substitution affecting the charge and bulkiness of residue 61 could account for the poor receptor binding and consequential weak toxic properties of this molecule.
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Affiliation(s)
- P Mansuelle
- Centre National de la Recherche Scientifique UA 1455, Faculté de Médecine, Secteur Nord, Marseille, France
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39
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Marangoni S, Ghiso J, Sampaio SV, Arantes EC, Giglio JR, Oliveira B, Frangione B. The complete amino acid sequence of toxin TsTX-VI isolated from the venom of the scorpion Tityus serrulatus. JOURNAL OF PROTEIN CHEMISTRY 1990; 9:595-601. [PMID: 2085384 DOI: 10.1007/bf01025013] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The complete sequence of the toxin TsTX-VI from the venom of the scorpion Tityus serrulatus Lutz and Mello is presented. The sequence has been determined by automated Edman analysis of the reduced and carboxymethylated protein as well as of the resulting peptides, obtained from S. aureus protease and tryptic digestions. TsTX-VI is composed of 62 residues and has a calculated molecular weight of 6717. Homology studies with other scorpion toxins show that TsTX-VI is more similar to the Old World than to the North American scorpion toxins. The hydropathic index indicates that TsTX-VI is more hydrophobic than Ts-gamma. Toxicity studies carried out in mice demonstrate that i.v. injection of TsTX-VI is unable to evoke the usual symptoms induced by the typical neurotoxins of this venom, but only a generalized allergic reaction. These properties are important in clarifying the relationship between primary structure and biological function of scorpion toxins.
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Affiliation(s)
- S Marangoni
- Department of Pathology, New York University Medical Center, New York 10016
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40
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Kopeyan C, Mansuelle P, Sampieri F, Brando T, Bahraoui EM, Rochat H, Granier C. Primary structure of scorpion anti-insect toxins isolated from the venom of Leiurus quinquestriatus quinquestriatus. FEBS Lett 1990; 261:423-6. [PMID: 2311768 DOI: 10.1016/0014-5793(90)80607-k] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The amino acid sequences of insect-selective scorpion toxins, purified from the venom of Leiurus quinquestriatus quinquestriatus, have been determined by automatic phenyl isothiocyanate degradation of the S-carboxymethylated proteins and derived proteolytic peptides. The excitatory toxin Lqq IT1 and Lqq IT1' (70 residues) show the shift of one half-cystine from an external position, which is characteristic of anti-mammal toxins, to an internal sequence position. Lqq IT2 (61 residues) displays the half-cystine residue in position 12, common to the sequence of all known anti-mammal toxins; it induces flaccid paralysis on insects but is non-toxic for the mouse. Lqq IT2 structurally defines a new type of anti-insect toxins from scorpion venoms. CD spectra and immunological data are in agreement with this finding.
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Affiliation(s)
- C Kopeyan
- Laboratoire de Biochimie-CNRS UA 1179-INSERM U172, Faculté de Médecine, Secteur Nord, Marseille, France
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41
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42
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Kharrat R, Darbon H, Rochat H, Granier C. Structure/activity relationships of scorpion alpha-toxins. Multiple residues contribute to the interaction with receptors. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 181:381-90. [PMID: 2714290 DOI: 10.1111/j.1432-1033.1989.tb14735.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Chemical modifications of tyrosine and tryptophan residues of scorpion alpha-neurotoxins II and III from Androctonus australis Hector were performed as well as modification of the two arginines and the alpha-amino group of toxin I. The pharmacological potencies of each derivative were assessed in vivo by LD50 measurement and in vitro by competition experiments with 125I-toxin for synaptosomal receptors. Arginine residues in positions 2 and 60 and the alpha-amino group of Androctonus toxin I were derivatized by p-hydroxyphenylglyoxal; the corresponding modified toxins exhibit low pharmacological potencies. Tryptophan 38 of toxin II and tryptophan 45 of toxin III were modified by nitrophenylsulfenyl chloride, leading respectively to a poorly and a fully active derivative. The tetranitromethane modification of tyrosine residues in positions 60, 5 and 14 of toxin III induced respectively 60%, 40% and 30% of loss of biological activity. Circular dichroic analysis indicated that for every derivative, except the nitrophenylsulfenyl derivative of Trp-45 of AaH III, the conformation of the toxin was not altered by derivatization. Conformational integrity was also confirmed by full activity of the derivatives in radioimmunoassays. Taken together, the results suggest that aromatic residues belonging to the conserved hydrophobic surface, to the C-terminal and to the loop region 37-44 are involved in the molecular mechanisms by which scorpion alpha-toxins act. Charged residues in the N-terminal and C-terminal also contribute to the high efficacy of the binding process. It appears that all important residues are clustered on one face of the toxin, suggesting a multipoint interaction with the proteins of the sodium channel.
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Affiliation(s)
- R Kharrat
- CNRS URA 37, INSERUM U. 172, Faculté de Médecine Secteur Nord, Marseille, France
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43
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Zhou XH, Yang D, Zhang JH, Liu CM, Lei KJ. Purification and N-terminal partial sequence of anti-epilepsy peptide from venom of the scorpion Buthus martensii Karsch. Biochem J 1989; 257:509-17. [PMID: 2930463 PMCID: PMC1135608 DOI: 10.1042/bj2570509] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An anti-epilepsy peptide (AEP) was isolated and purified from venom of the scorpion Buthus martensii Karsch. The purification procedure included CM-Sephadex C-50 chromatography, gel filtration on Sephadex G-50 and DEAE-Sephadex A-50 chromatography. Its homogeneity was demonstrated by pH 4.3 polyacrylamide-disc-gel electrophoresis, focusing electrophoresis and SDS/polyacrylamide-disc-gel electrophoresis. The Mr of this peptide, calculated from measurements in SDS/15%-polyacrylamide-disc-gel and SDS/20%-polyacrylamide-disc-gel electrophoresis, is 8300. The isoelectric point is 8.52 by pH 8-9.5-range isoelectric focusing. No haemorrhagic or toxic activities were found. No toxicity was found even after the dose reached 28 mg/kg. The pharmacological tests showed that the AEP had no effect on heart rate, blood pressure or electrocardiogram, but strongly inhibited epilepsy induced by coriaria lactone and cephaloridine. The fluorescence spectrum showed that the peptide has a strong emission peak at 337 nm. Amino acid analysis suggested that the AEP is composed of 66 residues from 18 amino acids and has an Mr of 8290. The sequence of the first 50 N-terminal residues is as follows: Asp-Gly-Tyr-Ile-Arg-Gly-Ser-Asp-Asn-Cys-Lys-Val-Ser-Cys-Leu-Leu-Gly-Asn- Glu-Gly - Cys-Asn-Lys-Glu-Cys-Arg-Ala-Tyr-Gly-Ala-Ser-Tyr-Gly-Tyr-Cys-Trp-Thr-Val- Lys-Leu - Ala-Gln-Asp-Cys-Glu-Gly-Leu-Pro-Asp-Thr-.
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Affiliation(s)
- X H Zhou
- Department of Biochemistry, Shenyang College of Pharmacy, China
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44
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Grandas A, Albericio F, Josa J, Giralt E, Pedroso E, Sabatier J, Van Rietschoten J. Convergent solid phase peptide synthesis. VII. Good yields in the coupling of protected segments on a solid support. Tetrahedron 1989. [DOI: 10.1016/s0040-4020(01)89099-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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45
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de Lima ME, Martin-Eauclaire MF, Hue B, Loret E, Diniz CR, Rochat H. On the binding of two scorpion toxins to the central nervous system of the cockroach Periplaneta americana. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0020-1790(89)90047-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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46
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Martin BM, Carbone E, Yatani A, Brown AM, Ramírez AN, Gurrola GB, Possani LD. Amino acid sequence and physiological characterization of toxins from the venom of the scorpion Centruroides limpidus tecomanus Hoffmann. Toxicon 1988; 26:785-94. [PMID: 2849217 DOI: 10.1016/0041-0101(88)90319-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The complete amino acid sequence of the major toxic component (II.20.3.4), named toxin 1, from the venom of the Mexican scorpion C. l. tecomanus is reported. The sequence (66 amino acids) was obtained by direct Edman degradation of reduced and alkylated toxin, followed by sequence determination of selected peptides separated after enzymatic cleavage with S. aureus V8 protease. In cultured chick dorsal root ganglion cells, 0.5 microM toxin 1 slowed down specifically the time course of Na+ current inactivation, while Ca2+ currents from the same preparation were little affected. In neonatal rat ventricular heart cells, toxin 1, at concentrations between 0.1 and 0.5 microM, reduced Na+ currents without changing the kinetics and Ca2+ currents were unaffected. Comparative analysis of the primary structure of this toxin with other scorpion toxins shows a high degree of similarity with the north American scorpion toxins. This analysis suggests that the 'fine tuning' of the molecular mechanism of action of these toxins is related to variations in the primary structure as well as to the type of membrane under study (tissue specificity).
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Affiliation(s)
- B M Martin
- National Institute of Mental Health, Molecular Neurogenetics Unit, Bethesda, MD 20892
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47
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Sabatier JM, Darbon H, Fourquet P, Rochat H, Van Rietschoten J. Reduction and reoxidation of the neurotoxin II from the scorpion Androctonus australis Hector. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1987; 30:125-34. [PMID: 3667073 DOI: 10.1111/j.1399-3011.1987.tb03320.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Reoxidation of the totally reduced scorpion neurotoxin II from Androctonus australis Hector (four disulfide bridges) has been investigated. The totally reduced toxin was highly insoluble in neutral and alkaline conditions, which prevented the use of the usual air oxidation process for renaturation. We tested a new method in which the reduced molecules were first solubilized in 10% (v/v) acetic acid and then oxidized by air through dialysis against a series of buffers with a slow pH gradient from 2.2 to 7.0 or 8.0. In this system, up to 95% of the protein was recovered in solution. Addition of reduced and oxidized glutathione accelerated refolding and also permitted a better recovery of fully active peptide as measured by both toxicity to mice and ability to displace 125I radiolabeled toxin II from its binding site on rat brain synaptosomal fractions. The reoxidation reaction could also be monitored directly by high pressure liquid chromatography. A strong effect of guanidine hydrochloride concentration as well as the temperature was observed both on the solubility of the reoxidation intermediates and on the refolding pathway. Finally, the method used, i.e. dialysis reoxidation with a pH gradient from 2.2 to 8.0 in 0.1 M sodium phosphate, 0.1 M sodium chloride, 20 mM guanidine hydrochloride, 1 mM oxidized and reduced glutathione allowed regeneration in high yield (70%) of a reoxidized toxin form indistinguishable from the native toxin. A minor stable and inactive molecular species (about 30%) showing a difference in mobility by electrophoresis was also detected.
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Affiliation(s)
- J M Sabatier
- U.D.C.- C.N.R.S. UA 1179, Faculty of Medicine North, Marseilles, France
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48
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Martin M, Garcia y Perez L, el Ayeb M, Kopeyan C, Bechis G, Jover E, Rochat H. Purification and chemical and biological characterizations of seven toxins from the Mexican scorpion, Centruroides suffusus suffusus. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61214-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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49
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Vargas O, Martin MF, Rochat H. Characterization of six toxins from the venom of the Moroccan scorpion Buthus occitanus mardochei. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 162:589-99. [PMID: 3104036 DOI: 10.1111/j.1432-1033.1987.tb10680.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
When the venom of the Moroccan scorpion Buthus occitanus mardochei was submitted to a combination of several chromatographic steps (including gel-filtration and ion-exchange chromatographies), seven proteins were obtained, six being lethal to mice. These proteins have been characterized by their chemical, immunological and toxic properties. The amino acid sequence (66 residues) of Bom III, the most noteworthy toxin of the venom as for its amino acid composition, is proposed following automatic sequencing of the reduced and S-methylated protein and of chymotryptic peptides. It was obvious that this sequence is somewhat different from those of toxins belonging to the same structural and immunological group (Bom III was found to be immunologically related to Buthus occitanus tunetanus toxins I and II which both share with it 56% of homology. Furthermore, Bom III was found to be unable to compete (as does Bot I) with toxin II of Androctonus australis Hector (an alpha-type toxin) for neurotoxin binding site 3 on the sodium channel of rat brain synaptosomes. Bom III was also unable to compete with toxin II of Centruroides suffusus suffusus (a beta-type toxin) to neurotoxin binding site 4 of the same channel.
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50
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Sampieri F, Habersetzer-Rochat C, Martin MF, Kopeyan C, Rochat H. Amino acid sequence of toxin XI of the scorpion Buthus occitanus tunetanus. Evidence of a mutation having an important effect upon neurotoxic activity. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1987; 29:231-7. [PMID: 3570664 DOI: 10.1111/j.1399-3011.1987.tb02249.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The complete amino acid sequence of toxin XI of the North African scorpion Buthus occitanus tunetanus has been elucidated by automatic sequencing of the reduced and alkylated toxin and of the peptides obtained after tryptic cleavage restricted to arginyl bonds. This toxin is structurally homologous to toxin II of Androctonus australis Hector, the most active among the alpha-toxins, but is far less potent, both in vivo and in vitro. This work points out 12 mutations, many of which are conservative. Nevertheless, the most striking difference is the replacement of the lysine residue at position 58, known to be important in the activity of AaH toxin II, by a valine residue. Thus, it seems that the presence of a positive charge at this location facilitates the interactions between the receptor on the sodium channel and the alpha-type toxins.
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