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Borges A, Lomonte B, Angulo Y, Acosta de Patiño H, Pascale JM, Otero R, Miranda RJ, De Sousa L, Graham MR, Gómez A, Pardal PP, Ishikawa E, Bonilla F, Castillo A, de Avila RAM, Gómez JP, Caro-López JA. Venom diversity in the Neotropical scorpion genus Tityus: Implications for antivenom design emerging from molecular and immunochemical analyses across endemic areas of scorpionism. Acta Trop 2020; 204:105346. [PMID: 31982434 DOI: 10.1016/j.actatropica.2020.105346] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 10/25/2022]
Abstract
Scorpions of the Neotropical genus Tityus are responsible for most severe envenomations in the Caribbean, South America, and Lower Central America (LCA). Although Tityus is taxonomically complex, contains high toxin polymorphism, and produces variable clinical manifestations, treatment is limited to antivenoms produced against species with restricted distributions. In this study, we explored the compositional and antigenic diversity of Tityus venoms to provide improved guidelines for the use of available antivenoms at a broader geographic scale. We used immunoblotting, competitive ELISA, and in vivo studies to compare reactivity against commercial antivenoms from Brazil, Venezuela, and Mexico, as well as MALDI-TOF mass spectrometry, cDNA sequencing, and phylogenetic analyses to assess venom sodium channel-active toxin (NaTx) content from medically important Tityus populations inhabiting Brazil, Colombia, Costa Rica, Ecuador, Panama, Trinidad and Tobago, and Venezuela. Additionally, we raised rabbit antibodies against Tityus venoms from LCA to test for cross-reactivity with congeneric species. The results suggest that Tityus spp. possess high venom antigenic diversity, underlying the existence of four toxinological regions in Tropical America, based on venom composition and immunochemical criteria: LCA/Colombia/Amazonia (Region I), Venezuela (Region II), southeast South America (Region III), and a fourth region encompassing species related to toxinologically divergent Tityus cerroazul. Importantly, our molecular and cross-reactivity results highlight the need for new antivenoms against species inhabiting Region I, where scorpions may produce venoms that are not significantly reactive against available antivenoms.
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Oliveira IS, Ferreira IG, Alexandre-Silva GM, Cerni FA, Cremonez CM, Arantes EC, Zottich U, Pucca MB. Scorpion toxins targeting Kv1.3 channels: insights into immunosuppression. J Venom Anim Toxins Incl Trop Dis 2019; 25:e148118. [PMID: 31131004 PMCID: PMC6483409 DOI: 10.1590/1678-9199-jvatitd-1481-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/17/2018] [Indexed: 01/26/2023] Open
Abstract
Scorpion venoms are natural sources of molecules that have, in addition to their
toxic function, potential therapeutic applications. In this source the
neurotoxins can be found especially those that act on potassium channels.
Potassium channels are responsible for maintaining the membrane potential in the
excitable cells, especially the voltage-dependent potassium channels (Kv),
including Kv1.3 channels. These channels (Kv1.3) are expressed by various types
of tissues and cells, being part of several physiological processes. However,
the major studies of Kv1.3 are performed on T cells due its importance on
autoimmune diseases. Scorpion toxins capable of acting on potassium channels
(KTx), mainly on Kv1.3 channels, have gained a prominent role for their possible
ability to control inflammatory autoimmune diseases. Some of these toxins have
already left bench trials and are being evaluated in clinical trials, presenting
great therapeutic potential. Thus, scorpion toxins are important natural
molecules that should not be overlooked in the treatment of autoimmune and other
diseases.
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Affiliation(s)
- Isadora S Oliveira
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Isabela G Ferreira
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Felipe A Cerni
- Ribeirão Preto Medical School, Department of Biochemistry and Immunology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Caroline M Cremonez
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Eliane C Arantes
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Umberto Zottich
- Medical School, Federal University of Roraima, Boa Vista, RR, Brazil
| | - Manuela B Pucca
- Medical School, Federal University of Roraima, Boa Vista, RR, Brazil
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3
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Ward MJ, Ellsworth SA, Nystrom GS. A global accounting of medically significant scorpions: Epidemiology, major toxins, and comparative resources in harmless counterparts. Toxicon 2018; 151:137-155. [DOI: 10.1016/j.toxicon.2018.07.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/25/2018] [Accepted: 07/05/2018] [Indexed: 01/18/2023]
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4
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Batista C, Martins J, Restano-Cassulini R, Coronas F, Zamudio F, Procópio R, Possani L. Venom characterization of the Amazonian scorpion Tityus metuendus. Toxicon 2018; 143:51-58. [DOI: 10.1016/j.toxicon.2018.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 01/09/2023]
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5
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Housley DM, Housley GD, Liddell MJ, Jennings EA. Scorpion toxin peptide action at the ion channel subunit level. Neuropharmacology 2016; 127:46-78. [PMID: 27729239 DOI: 10.1016/j.neuropharm.2016.10.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/06/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022]
Abstract
This review categorizes functionally validated actions of defined scorpion toxin (SCTX) neuropeptides across ion channel subclasses, highlighting key trends in this rapidly evolving field. Scorpion envenomation is a common event in many tropical and subtropical countries, with neuropharmacological actions, particularly autonomic nervous system modulation, causing significant mortality. The primary active agents within scorpion venoms are a diverse group of small neuropeptides that elicit specific potent actions across a wide range of ion channel classes. The identification and functional characterisation of these SCTX peptides has tremendous potential for development of novel pharmaceuticals that advance knowledge of ion channels and establish lead compounds for treatment of excitable tissue disorders. This review delineates the unique specificities of 320 individual SCTX peptides that collectively act on 41 ion channel subclasses. Thus the SCTX research field has significant translational implications for pathophysiology spanning neurotransmission, neurohumoral signalling, sensori-motor systems and excitation-contraction coupling. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- David M Housley
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Michael J Liddell
- Centre for Tropical Environmental and Sustainability Science and College of Science & Engineering, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia
| | - Ernest A Jennings
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Queensland 4878, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns Campus, QLD, Australia
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6
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Potassium channel blockers from the venom of the Brazilian scorpion Tityus serrulatus (). Toxicon 2016; 119:253-65. [PMID: 27349167 DOI: 10.1016/j.toxicon.2016.06.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/06/2016] [Accepted: 06/24/2016] [Indexed: 02/05/2023]
Abstract
Potassium (K(+)) channels are trans-membrane proteins, which play a key role in cellular excitability and signal transduction pathways. Scorpion toxins blocking the ion-conducting pore from the external side have been invaluable probes to elucidate the structural, functional, and physio-pathological characteristics of these ion channels. This review will focus on the interaction between K(+) channels and their peptide blockers isolated from the venom of the scorpion Tityus serrulatus, which is considered as the most dangerous scorpion in Brazil, in particular in Minas-Gerais State, where many casualties are described each year. The primary mechanisms of action of these K(+) blockers will be discussed in correlation with their structure, very often non-canonical compared to those of other well known K(+) channels blockers purified from other scorpion venoms. Also, special attention will be brought to the most recent data obtained by proteomic and transcriptomic analyses on Tityus serrulatus venoms and venom glands.
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7
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Kuzmenkov AI, Grishin EV, Vassilevski AA. Diversity of Potassium Channel Ligands: Focus on Scorpion Toxins. BIOCHEMISTRY (MOSCOW) 2016; 80:1764-99. [DOI: 10.1134/s0006297915130118] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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8
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Coronas FIV, Diego-García E, Restano-Cassulini R, de Roodt AR, Possani LD. Biochemical and physiological characterization of a new Na(+)-channel specific peptide from the venom of the Argentinean scorpion Tityus trivittatus. Peptides 2015; 68:11-6. [PMID: 24862827 DOI: 10.1016/j.peptides.2014.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 01/12/2023]
Abstract
A new peptide with 61 amino acids cross-linked by 4 disulfide bridges, with molecular weight of 6938.12Da, and an amidated C-terminal amino acid residue was purified and characterized. The primary structure was obtained by direct Edman degradation and sequencing its gene. The peptide is lethal to mammals and was shown to be similar (95% identity) to toxin Ts1 (gamma toxin) from the Brazilian scorpion Tityus serrulatus; it was named Tt1g (from T. trivittatus toxin 1 gamma-like). Tt1g was assayed on several sub-types of Na(+)-channels showing displacement of the currents to more negative voltages, being the hNav1.3 the most affected channel. This toxin displays characteristics typical to the β-type sodium scorpion toxins. Lethality tests and physiological assays indicate that this peptide is probably the most important toxic component of this species of scorpion, known for causing human fatalities in the South American continent.
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Affiliation(s)
- Fredy I V Coronas
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico
| | - Elia Diego-García
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico
| | - Rita Restano-Cassulini
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico
| | - Adolfo R de Roodt
- Laboratorio de Toxinopatología, Centro de Patología Experimental y Aplicada, Facultad de Medicina, Universidad de Buenos Aires and Ministerio de Salud de la Nación, Argentina.
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico.
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9
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de Roodt AR. Comments on Environmental and Sanitary Aspects of the Scorpionism by Tityus trivittatus in Buenos Aires City, Argentina. Toxins (Basel) 2014; 6:1434-52. [PMID: 24759176 PMCID: PMC4014744 DOI: 10.3390/toxins6041434] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/21/2014] [Accepted: 04/03/2014] [Indexed: 11/21/2022] Open
Abstract
Deaths by venomous animals are medical emergencies that can lead to death and thus constitute sanitary problems in some regions of the world. In the South of America, the accidents by these animals are a common sanitary problem especially in warm, tropical or subtropical regions, related with rural work in several countries. Argentina is located in the extreme South of South America and a minor part of the continental surface is in tropical or subtropical regions, where most of the accidents by venomous animals happen. However, in the big cities in the center and South of the country, with no relation to rural work, scorpionism, mostly due to the synanthropic and facultative parthenogenetic scorpion Tityus trivittatus, has become a sanitary problem in the last few decades. This scorpion is present in the biggest cities of Argentina and in the last decades has killed over 20 children in provinces of the center and north of the country, mostly in big cities. In addition, it seems that this species is growing and spreading in new regions of the cities. In this revision, some characteristics of this scorpion regarding its habitat, spreading in Buenos Aires city, combat measures and available treatments are discussed.
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Affiliation(s)
- Adolfo Rafael de Roodt
- Laboratory of Toxinopathology, Center of Applied and Experimental Pathology, Faculty of Medicine, University of Buenos Aires/National Ministry of Health, Uriburu 950, 5 Piso, Lab. 555, Buenos Aires 1114, Argentina.
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10
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Electrophysiological characterization of Ts6 and Ts7, K⁺ channel toxins isolated through an improved Tityus serrulatus venom purification procedure. Toxins (Basel) 2014; 6:892-913. [PMID: 24590385 PMCID: PMC3968367 DOI: 10.3390/toxins6030892] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/24/2014] [Accepted: 02/17/2014] [Indexed: 01/09/2023] Open
Abstract
In Brazil, Tityus serrulatus (Ts) is the species responsible for most of the scorpion related accidents. Among the Ts toxins, the neurotoxins with action on potassium channels (α-KTx) present high interest, due to their effect in the envenoming process and the ion channel specificity they display. The α-KTx toxins family is the most relevant because its toxins can be used as therapeutic tools for specific target cells. The improved isolation method provided toxins with high resolution, obtaining pure Ts6 and Ts7 in two chromatographic steps. The effects of Ts6 and Ts7 toxins were evaluated in 14 different types of potassium channels using the voltage-clamp technique with two-microelectrodes. Ts6 toxin shows high affinity for Kv1.2, Kv1.3 and Shaker IR, blocking these channels in low concentrations. Moreover, Ts6 blocks the Kv1.3 channel in picomolar concentrations with an IC50 of 0.55 nM and therefore could be of valuable assistance to further designing immunosuppressive therapeutics. Ts7 toxin blocks multiple subtypes channels, showing low selectivity among the channels analyzed. This work also stands out in its attempt to elucidate the residues important for interacting with each channel and, in the near future, to model a desired drug.
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11
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Schwartz EF, Bartok A, Schwartz CA, Papp F, Gómez-Lagunas F, Panyi G, Possani LD. OcyKTx2, a new K⁺-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum. Peptides 2013; 46:40-6. [PMID: 23684923 DOI: 10.1016/j.peptides.2013.04.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 04/25/2013] [Accepted: 04/27/2013] [Indexed: 11/26/2022]
Abstract
Opisthacanthus cayaporum belongs to the Liochelidae family, and the scorpions from this genus occur in southern Africa, Central America and South America and, therefore, can be considered a true Gondwana heritage. In this communication, the isolation, primary structure characterization, and K⁺-channel blocking activity of new peptide from this scorpion venom are reported. OcyKTx2 is a 34 amino acid long peptide with four disulfide bridges and molecular mass of 3807 Da. Electrophysiological assays conducted with pure OcyKTx2 showed that this toxin reversibly blocks Shaker B K⁺-channels with a Kd of 82 nM, and presents an even better affinity toward hKv1.3, blocking it with a Kd of ∼18 nM. OcyKTx2 shares high sequence identity with peptides belonging to subfamily 6 of α-KTxs that clustered very closely in the phylogenetic tree included here. Sequence comparison, chain length and number of disulfide bridges analysis classify OcyKTx2 into subfamily 6 of the α-KTx scorpion toxins (systematic name, α-KTx6.17).
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Affiliation(s)
- Elisabeth F Schwartz
- Department of Physiological Sciences, Institute of Biological Sciences, University of Brasilia, Brasilia, 70910-900 DF, Brazil.
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12
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Bergeron ZL, Bingham JP. Scorpion toxins specific for potassium (K+) channels: a historical overview of peptide bioengineering. Toxins (Basel) 2012. [PMID: 23202307 PMCID: PMC3509699 DOI: 10.3390/toxins4111082] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scorpion toxins have been central to the investigation and understanding of the physiological role of potassium (K+) channels and their expansive function in membrane biophysics. As highly specific probes, toxins have revealed a great deal about channel structure and the correlation between mutations, altered regulation and a number of human pathologies. Radio- and fluorescently-labeled toxin isoforms have contributed to localization studies of channel subtypes in expressing cells, and have been further used in competitive displacement assays for the identification of additional novel ligands for use in research and medicine. Chimeric toxins have been designed from multiple peptide scaffolds to probe channel isoform specificity, while advanced epitope chimerization has aided in the development of novel molecular therapeutics. Peptide backbone cyclization has been utilized to enhance therapeutic efficiency by augmenting serum stability and toxin half-life in vivo as a number of K+-channel isoforms have been identified with essential roles in disease states ranging from HIV, T-cell mediated autoimmune disease and hypertension to various cardiac arrhythmias and Malaria. Bioengineered scorpion toxins have been monumental to the evolution of channel science, and are now serving as templates for the development of invaluable experimental molecular therapeutics.
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Affiliation(s)
- Zachary L Bergeron
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
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13
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Zoccal KF, Bitencourt CDS, Sorgi CA, Bordon KDCF, Sampaio SV, Arantes EC, Faccioli LH. Ts6 and Ts2 from Tityus serrulatus venom induce inflammation by mechanisms dependent on lipid mediators and cytokine production. Toxicon 2012; 61:1-10. [PMID: 23085190 DOI: 10.1016/j.toxicon.2012.10.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/27/2012] [Accepted: 10/10/2012] [Indexed: 10/27/2022]
Abstract
Inflammatory mediators are thought to be involved in the systemic and local immune response induced by the Tityus serrulatus scorpion envenomation. New functional aspects of lipid mediators have recently been described. Here, we examine the unreported role of lipid mediators in cell recruitment to the peritoneal cavity after an injection with Ts2 or Ts6 toxins isolated from the T. serrulatus scorpion venom. In this report, we demonstrate that following a single intraperitoneal (i.p.) injection of Ts2 or Ts6 (250 μg/kg) in mice, there was an induction of leukocytosis with a predominance of neutrophils observed at 4, 24, 48 and 96 h. Moreover, total protein, leukotriene (LT)B(4), prostaglandin (PG)E(2) and pro-inflammatory cytokine levels were increased. We also observed an increase of regulatory cytokines, including interleukin (IL)-10, after the Ts2 injection. Finally, we observed that Ts2 or Ts6 injection in 5-lipoxygenase (LO) deficient mice and in wild type (WT) 129sv mice pre-treated with LTs and PGs inhibitors (MK-886 and celecoxib, respectively) a reduction the influx of leukocytes occurs in comparison to WT. The recruitment of these cells demonstrated a phenotype characteristic of neutrophils, macrophages, CD4 and CD8 lymphocytes expressing GR1+, F4/80+, CD3+/CD4+ and CD3+/CD8+, respectively. In conclusion, our data demonstrate that Ts2 and Ts6 induce inflammation by mechanisms dependent on lipid mediators and cytokine production. Ts2 may play a regulatory role whereas Ts6 exhibits pro-inflammatory activity exclusively.
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Affiliation(s)
- Karina Furlani Zoccal
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
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14
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Saucedo AL, Flores-Solis D, Rodríguez de la Vega RC, Ramírez-Cordero B, Hernández-López R, Cano-Sánchez P, Noriega Navarro R, García-Valdés J, Coronas-Valderrama F, de Roodt A, Brieba LG, Domingos Possani L, del Río-Portilla F. New tricks of an old pattern: structural versatility of scorpion toxins with common cysteine spacing. J Biol Chem 2012; 287:12321-30. [PMID: 22238341 DOI: 10.1074/jbc.m111.329607] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Scorpion venoms are a rich source of K(+) channel-blocking peptides. For the most part, they are structurally related small disulfide-rich proteins containing a conserved pattern of six cysteines that is assumed to dictate their common three-dimensional folding. In the conventional pattern, two disulfide bridges connect an α-helical segment to the C-terminal strand of a double- or triple-stranded β-sheet, conforming a cystine-stabilized α/β scaffold (CSα/β). Here we show that two K(+) channel-blocking peptides from Tityus scorpions conserve the cysteine spacing of common scorpion venom peptides but display an unconventional disulfide pattern, accompanied by a complete rearrangement of the secondary structure topology into a CS helix-loop-helix fold. Sequence and structural comparisons of the peptides adopting this novel fold suggest that it would be a new elaboration of the widespread CSα/β scaffold, thus revealing an unexpected structural versatility of these small disulfide-rich proteins. Acknowledgment of such versatility is important to understand how venom structural complexity emerged on a limited number of molecular scaffolds.
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Affiliation(s)
- Alma Leticia Saucedo
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, D.F., 04510, México
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15
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de Roodt AR, Coronas FI, Lago N, González ME, Laskowicz RD, Beltramino JC, Saavedra S, López RA, Reati GJ, Vucharchuk MG, Bazán E, Varni L, Salomón OD, Possani LD. General biochemical and immunological characterization of the venom from the scorpion Tityus trivittatus of Argentina. Toxicon 2010; 55:307-19. [DOI: 10.1016/j.toxicon.2009.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 08/11/2009] [Accepted: 08/11/2009] [Indexed: 11/17/2022]
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16
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Two novel ergtoxins, blockers of K+-channels, purified from the Mexican scorpion Centruroides elegans elegans. Neurochem Res 2008; 33:1525-33. [PMID: 18338253 DOI: 10.1007/s11064-008-9634-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 02/19/2008] [Indexed: 10/22/2022]
Abstract
Voltage-gated potassium channels of the ether-a-go-go related gene (ERG) family are implicated in many important cellular processes. Three such genes have been cloned (erg1, erg2 and erg3) and shown to be expressed in the central nervous system (CNS) of mammalians. This communication describes the isolation and characterization of two isoforms of scorpion toxin (CeErg4 and CeErg5, systematic nomenclature gamma-KTx1.7 and gamma-KTx1.8, respectively) that can discriminate the various subtypes of ERG channels of human and rat. These peptides were purified from the venom of the Mexican scorpion Centruroides elegans elegans. They contain 42 amino acid residues, tightly folded by four disulfide bridges. Both peptides block in a reversible manner human and rat ERG1 channels, but have no effect on human ERG2. They also block completely and irreversibly the rat ERG2 and the human ERG3 channels hence are excellent tools for the discrimination of the various sub-types of ion-channels studied.
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17
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Batista CVF, Román-González SA, Salas-Castillo SP, Zamudio FZ, Gómez-Lagunas F, Possani LD. Proteomic analysis of the venom from the scorpion Tityus stigmurus: biochemical and physiological comparison with other Tityus species. Comp Biochem Physiol C Toxicol Pharmacol 2007; 146:147-157. [PMID: 17270501 DOI: 10.1016/j.cbpc.2006.12.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 11/21/2006] [Accepted: 12/07/2006] [Indexed: 11/21/2022]
Abstract
The venom from the Brazilian scorpion Tityus stigmurus was fractionated by high performance liquid chromatography (HPLC) and the corresponding components were used for molecular mass determination using electrospray ion trap mass spectrometry. One hundred distinct components were clearly assigned showing molecular masses from 216.5 to 44,800.0 Da. Fifteen new components were isolated and sequenced, four of them to completion: Tst-3 (similar to Na(+) channel specific scorpion toxins), Tst-17 (a K(+) channel blocking peptide similar to Tc1), Tst beta KTx (a peptide with identical sequence as that of TsTX-K beta toxin earlier described to exist in T. serrulatus venom) and finally a novel proline-rich peptide of unknown function. Among the eleven components partially sequenced were two enzymes: hyaluronidase and lysozyme. The first enzyme has a molecular mass of 44,800.0 Da. This enzyme showed high activity against the substrate hyaluronan in vitro. Amino acid sequence of the second enzyme showed that it is similar to other known lysozymes, with similar molecular mass and sequence to that of bona fide lysozymes reported in public protein data banks. Finally, this communication reports a correlation among HPLC retention times and molecular masses of folded scorpion toxins as well as a comparative structural and physiological analysis of components from the venom of several species of the genus Tityus.
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Affiliation(s)
- C V F Batista
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - S A Román-González
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - S P Salas-Castillo
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - F Z Zamudio
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - F Gómez-Lagunas
- Department of Physiology, Medical School, National Autonomous University of Mexico, Ciudad Universitaria, Mexico D.F. 04510, Mexico
| | - L D Possani
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico.
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18
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Diego-García E, Schwartz EF, D'Suze G, González SAR, Batista CVF, García BI, de la Vega RCR, Possani LD. Wide phylogenetic distribution of Scorpine and long-chain beta-KTx-like peptides in scorpion venoms: identification of "orphan" components. Peptides 2007; 28:31-7. [PMID: 17141373 DOI: 10.1016/j.peptides.2006.06.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 06/27/2006] [Accepted: 06/27/2006] [Indexed: 11/15/2022]
Abstract
Scorpine and toxins specific for potassium channels of the family beta (beta-Ktx) are two types of structurally related scorpion venom components, characterized by an unusually long extended N-terminal segment, followed by a Cys-rich domain with some resemblance to other scorpion toxins. In this communication, we report evidence supporting the ubiquitous presence of Scorpine and beta-KTx-like polypeptides and their precursors in scorpions of the genus Tityus of the family Buthidae, but also included is the first example of such peptides in scorpions from the family Iuridae. Seven new beta-KTxs or Scorpine-like peptides and precursors are reported: five from the genus Tityus (T. costatus, T. discrepans and T. trivittatus) and two from Hadrurus gertschi. The cDNA precursors for all of these peptides were obtained by molecular cloning and their presence in the venoms were confirmed for various peptides. Analysis of the sequences revealed the existence of at least three distinct groups: (1) beta-KTx-like peptides from buthids; (2) Scorpine-like peptides from scorpionid and iurid scorpions; (3) heterogeneous peptides similar to BmTXKbeta of buthids and iurids. The biological function for most of these peptides is not well known; that is why they are here considered "orphan" peptides.
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Affiliation(s)
- Elia Diego-García
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Cuernavaca 62210, Mexico
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19
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Abdel-Mottaleb Y, Coronas FV, de Roodt AR, Possani LD, Tytgat J. A novel toxin from the venom of the scorpionTityus trivittatus, is the first member of a new α-KTX subfamily. FEBS Lett 2006; 580:592-6. [PMID: 16405970 DOI: 10.1016/j.febslet.2005.12.073] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Accepted: 12/17/2005] [Indexed: 11/27/2022]
Abstract
The first example of a new sub-family of toxins (alpha-KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine-stabilized alpha/beta scaffold with a pI value of 8.98. The sequence identities with all the other known alpha-KTx are less than 40%. Its effects were verified using seven different cloned K(+) channels (vertebrate Kv1.1-1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin-induced effects show large differences among the different K(+) channels and a preference towards Kv1.3 (EC50=7.9+/-1.4 nM).
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Affiliation(s)
- Yousra Abdel-Mottaleb
- Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Postbus 922, 3000 Leuven, Belgium
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20
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Oyama S, Pristovsek P, Franzoni L, Pertinhez TA, Schininá E, Lücke C, Rüterjans H, Arantes EC, Spisni A. Probing the pH-dependent structural features of alpha-KTx12.1, a potassium channel blocker from the scorpion Tityus serrulatus. Protein Sci 2005; 14:1025-38. [PMID: 15772309 PMCID: PMC2253457 DOI: 10.1110/ps.041131205] [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: 10/25/2022]
Abstract
Potassium channels are widespread in living cells and are involved in many diseases. The scorpion toxin alpha-KTx(12.1) interacts with various K(+) channels, suggesting its capacity to match diverse channel pores. It is recognized that tissue injuries may affect the pH at toxins site of action, thereby modulating both protein conformation and activity. To better understand its molecular mechanism of action, we studied alpha-KTx(12.1) using pH as a tool to explore its plasticity and NMR in combination with MD calculations to detect it. The toxin solution structure consists of an alpha-helix and a triple-stranded beta-sheet stabilized by four disulfide bridges. The NMR results show, in addition, that His28 possesses an unusually low pK(a) of 5.2. The best set of protein conformers is obtained at pH 4.5, while at pH 7.0, the reduced number of NOEs resulting from a faster hydrogen exchange does not allow to reach a good structural convergence. Nonetheless, MD calculations show that the toxin structure does not vary significantly in that pH range, while conformational changes and modifications of the surface charge distribution occur when His28 is fully protonated. Moreover, essential dynamics analysis reveals variations in the toxin's coherent motions. In conclusion, His28, with its low pK(a) value, provides alpha-KTx(12.1) with the ability to preserve its active conformation over a wide pH interval, thus expanding the range of cellular conditions where the toxin can fully exhibit its activity. Overall, the results further underline the role of histidine as a natural controller of proteins' functionality.
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Affiliation(s)
- Sérgio Oyama
- Department of Experimental Medicine, Section of Chemistry and Structural Biochemistry, University of Parma, Via Volturno 39, 43100 Parma, Italy
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21
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Valdez-Cruz NA, Dávila S, Licea A, Corona M, Zamudio FZ, García-Valdes J, Boyer L, Possani LD. Biochemical, genetic and physiological characterization of venom components from two species of scorpions: Centruroides exilicauda Wood and Centruroides sculpturatus Ewing. Biochimie 2005; 86:387-96. [PMID: 15358055 DOI: 10.1016/j.biochi.2004.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Accepted: 05/14/2004] [Indexed: 11/17/2022]
Abstract
Current literature concerning the taxonomic names of two possibly distinct species of scorpions from the genus Centruroides (sculpturatus and/or exilicauda) is controversial. This communication reports the results of biochemical, genetic and electrophysiological experiments conducted with C. exilicauda Wood of Baja California (Mexico) and C. sculpturatus Ewing of Arizona (USA). The chromatographic profile fractionation of the soluble venom from both species of scorpions is different. The N-terminal amino acid sequence for nine toxins of C. exilicauda was determined and compared with those from C. sculpturatus. Lethality tests conducted in mice support the idea that C. exilicauda venom should be expected to be medically less important than C. sculpturatus. Thirteen genes from the venomous glands of the scorpion C. exilicauda were obtained and compared with previously published sequences from genes of the species C. sculpturatus. Genes coding for cytochrome oxidase I and II of both species were also sequenced. A phylogenetic tree was generated with this information showing important differences between them. Additionally, the results of electrophysiological assays conducted with the venom from both species on the Ca(2+)-dependent K(+)-channels, showed significant differences. These results strongly support the conclusion that C. exilicauda and C. sculpturatus are in fact two distinct species of scorpions.
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Affiliation(s)
- Norma A Valdez-Cruz
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
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22
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Diego-García E, Batista CVF, García-Gómez BI, Lucas S, Candido DM, Gómez-Lagunas F, Possani LD. The Brazilian scorpion Tityus costatus Karsch: genes, peptides and function. Toxicon 2004; 45:273-83. [PMID: 15683865 DOI: 10.1016/j.toxicon.2004.10.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 10/19/2004] [Accepted: 10/20/2004] [Indexed: 10/26/2022]
Abstract
The venom of the scorpion Tityus costatus contains peptides toxic to humans but scarce information on their structure and function is available. Here, we report the separation of 50 different components by high performance liquid chromatography and the identification of approximately 90 distinct components by mass spectrometry analysis, with molecular weights varying from 413 to 45482 atomic mass units. Four peptides were fully sequenced: (i) a butantoxin-like peptide that blocks Shaker K+ channel; (ii) an insect toxin-like peptide; (iii) a scorpine-like peptide, and a short heptapeptide of unknown function. Fifteen peptides were directly sequenced at the N-terminal region, among which are components toxic to mice. A cDNA library was constructed and 13 clones were isolated and sequenced. Some of these peptides and genes are similar to other known scorpion toxins. Based on these results, stings by scorpions of the species Tityus costatus should be taken with caution by medical doctors.
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Affiliation(s)
- Elia Diego-García
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
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23
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Rodríguez de la Vega RC, Merino E, Becerril B, Possani LD. Novel interactions between K+ channels and scorpion toxins. Trends Pharmacol Sci 2003; 24:222-7. [PMID: 12767720 DOI: 10.1016/s0165-6147(03)00080-4] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
K(+) channels are macromolecules embedded in biological membranes, where they play a key role in cellular excitability and signal transduction pathways. Knowledge of their structure should help improve our understanding of their function and lead to the design of therapeutic compounds. Most pharmacological and structural characteristics of these channels have been elucidated by using high-affinity channel blockers isolated from scorpion venoms. Recent data on the three-dimensional structures of K(+) channels and novel scorpion toxins suggest a variety of novel interacting modes of these channels and toxins, which should help increase our understanding of the K(+) channel structure-function relationship.
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Affiliation(s)
- Ricardo C Rodríguez de la Vega
- Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico
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