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Xiao L, Gurrola GB, Zhang J, Valdivia CR, SanMartin M, Zamudio FZ, Zhang L, Possani LD, Valdivia HH. Structure-function relationships of peptides forming the calcin family of ryanodine receptor ligands. J Gen Physiol 2017; 147:375-94. [PMID: 27114612 PMCID: PMC4845687 DOI: 10.1085/jgp.201511499] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 03/21/2016] [Indexed: 12/22/2022] Open
Abstract
Calcins are a novel family of scorpion peptides that bind with high affinity to ryanodine receptors (RyRs) and increase their activity by inducing subconductance states. Here, we provide a comprehensive analysis of the structure-function relationships of the eight calcins known to date, based on their primary sequence, three-dimensional modeling, and functional effects on skeletal RyRs (RyR1). Primary sequence alignment and evolutionary analysis show high similarity among all calcins (≥78.8% identity). Other common characteristics include an inhibitor cysteine knot (ICK) motif stabilized by three pairs of disulfide bridges and a dipole moment (DM) formed by positively charged residues clustering on one side of the molecule and neutral and negatively charged residues segregating on the opposite side. [(3)H]Ryanodine binding assays, used as an index of the open probability of RyRs, reveal that all eight calcins activate RyR1 dose-dependently with Kd values spanning approximately three orders of magnitude and in the following rank order: opicalcin1 > opicalcin2 > vejocalcin > hemicalcin > imperacalcin > hadrucalcin > maurocalcin >> urocalcin. All calcins significantly augment the bell-shaped [Ca(2+)]-[(3)H]ryanodine binding curve with variable effects on the affinity constants for Ca(2+) activation and inactivation. In single channel recordings, calcins induce the appearance of a subconductance state in RyR1 that has a unique fractional value (∼20% to ∼60% of the full conductance state) but bears no relationship to binding affinity, DM, or capacity to stimulate Ca(2+) release. Except for urocalcin, all calcins at 100 nM concentration stimulate Ca(2+) release and deplete Ca(2+) load from skeletal sarcoplasmic reticulum. The natural variation within the calcin family of peptides offers a diversified set of high-affinity ligands with the capacity to modulate RyRs with high dynamic range and potency.
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Affiliation(s)
- Liang Xiao
- Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Georgina B Gurrola
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62271, México Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jing Zhang
- Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Carmen R Valdivia
- Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Mario SanMartin
- Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Fernando Z Zamudio
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62271, México Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Liming Zhang
- Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62271, México
| | - Héctor H Valdivia
- Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
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Jiménez-Vargas JM, Possani LD, Luna-Ramírez K. Arthropod toxins acting on neuronal potassium channels. Neuropharmacology 2017; 127:139-160. [PMID: 28941737 DOI: 10.1016/j.neuropharm.2017.09.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Abstract
Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels. A brief description of the K+ channels classification and structure is included and a compendium of neuronal K+ channels and the arthropod toxins that modify them have been listed. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Juana María Jiménez-Vargas
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Karen Luna-Ramírez
- Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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Rokyta DR, Ward MJ. Venom-gland transcriptomics and venom proteomics of the black-back scorpion (Hadrurus spadix) reveal detectability challenges and an unexplored realm of animal toxin diversity. Toxicon 2017; 128:23-37. [DOI: 10.1016/j.toxicon.2017.01.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 10/20/2022]
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Xiao M, Ding L, Yang W, Chai L, Sun Y, Yang X, Li D, Zhang H, Li W, Cao Z, Wu Y, Li J, Li S, Chen Z. St20, a new venomous animal derived natural peptide with immunosuppressive and anti-inflammatory activities. Toxicon 2017; 127:37-43. [PMID: 28077339 DOI: 10.1016/j.toxicon.2017.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 10/20/2022]
Abstract
Peptide toxins from venomous animals are natural resources with diverse biological functions and therapeutic potential towards human diseases. For venomous scorpions, many valuable peptide toxins have been discovered from Buthidae scorpions, but few works were done about non-buthidae scorpions. Here, we cloned and characterized the first disulfide-bridged toxin peptide St20 from the non-buthidae scorpion Scorpiops tibetanus. St20 has a putative 23-residue signal peptide, followed by a presumed 34-residue mature peptide including 8 cysteines. Sequence alignments and structural analysis suggested that St20 is a new member of α-KTx23 scorpion toxin subfamily with a conserved CSα/β structural fold. Functional studies showed that St20 inhibited human T lymphocyte surface marker CD69 expression and cytokine IL-2 secretion. Beside this, St20 inhibited two important pro-inflammatory factors TNF-α and IFN-γ secretion in the activated human T lymphocyte. Animal experiments showed that the delayed-type hypersensitivity response in rat autoimmune disease model was ameliorated in the present of peptide toxin St20. Together, our results showed that St20 is the first disulfide-bridged toxin peptide from the non-buthidae scorpion Scorpiops tibetanus with immunosuppressive and anti-inflammatory activities, suggesting that toxins from non-buthidae scorpions might be a new source of peptide drug discovery towards human diseases.
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Affiliation(s)
- Min Xiao
- Department of Emergency Medicine, Taihe Hospital, Hubei University of Medicine, Hubei, China
| | - Li Ding
- Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Department of Clinical Laboratory, Dongfeng Hospital, Hubei University of Medicine, Hubei, China
| | - Weishan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Lin Chai
- Department of Emergency Medicine, Taihe Hospital, Hubei University of Medicine, Hubei, China
| | - Yuwen Sun
- Department of Emergency Medicine, Taihe Hospital, Hubei University of Medicine, Hubei, China
| | - Xianyi Yang
- Department of Emergency Medicine, Taihe Hospital, Hubei University of Medicine, Hubei, China
| | - Dandan Li
- Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Hua Zhang
- Department of Clinical Laboratory, Dongfeng Hospital, Hubei University of Medicine, Hubei, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Jian Li
- Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Shan Li
- Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Department of Clinical Laboratory, Dongfeng Hospital, Hubei University of Medicine, Hubei, China
| | - Zongyun Chen
- Department of Emergency Medicine, Taihe Hospital, Hubei University of Medicine, Hubei, China; Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Department of Clinical Laboratory, Dongfeng Hospital, Hubei University of Medicine, Hubei, China.
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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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Zhong J, Zeng XC, Zeng X, Nie Y, Zhang L, Wu S, Bao A. Transcriptomic analysis of the venom glands from the scorpion Hadogenes troglodytes revealed unique and extremely high diversity of the venom peptides. J Proteomics 2016; 150:40-62. [PMID: 27519694 DOI: 10.1016/j.jprot.2016.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/25/2016] [Accepted: 08/06/2016] [Indexed: 12/14/2022]
Abstract
Hadogenes is a genus of large African scorpions with 18 described species. However, little is known about the venom peptide composition of any species from Hadogenes so far. Here, we fully explored the composition of venom gland peptides from Hadogenes troglodytes using transcriptomic approach. We discovered 121 novel peptides from the scorpion, including 20 new-type peptides cross-linked with one, two, three, four or seven disulfide bridges, respectively, 11 novel K+-channel toxin-like peptides, 2 novel ryanodine receptors-specific toxin-like peptides, a unique peptide containing the cysteine knots of spider toxins, 15 novel La1-like toxins, 3 novel TIL domain-containing peptides, 5 novel peptides with atypical cysteine patterns, 19 novel antimicrobial peptides, 6 novel cysteine-free peptides and 39 new-type cysteine-free peptides. Among them, the new-type peptides are largely dominant; this highlights the unique diversity of the venom gland peptides from H. troglodytes. Some of the new peptides would serve as new molecular probes for the investigations of cellular ion channels and other receptors, or offer new templates for the development of therapeutic drugs for the treatment of ion channel-associated diseases, and infections caused by antibiotics-resistant pathogens. BIOLOGICAL SIGNIFICANCE In this study, we fully explored the composition of venom gland peptides from the scorpion Hadogenes troglodytes using transcriptomic approach. We discovered a total of 121 novel peptides from the venom glands of the scorpion, of which new-type peptides are largely dominant. These data highlight the unique diversity of the venom gland peptides from the scorpion H. troglodytes, gain insights into new mechanisms for the scorpion to subdue its prey and predators, and enlarge the protein database of scorpion venom glands. The discovery of a lot of novel peptides provides new templates for the development of therapeutic drugs, and offers new molecular materials for the basic researches of various cellular receptors, and for the evolutionary investigations of scorpion toxins.
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Affiliation(s)
- Jie Zhong
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Xian-Chun Zeng
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China.
| | - Xin Zeng
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Yao Nie
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Lei Zhang
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Shifen Wu
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Aorigele Bao
- Department of Biological Science and Technology, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
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7
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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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8
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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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Schwartz EF, Mourão CBF, Moreira KG, Camargos TS, Mortari MR. Arthropod venoms: A vast arsenal of insecticidal neuropeptides. Biopolymers 2012. [DOI: 10.1002/bip.22100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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10
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Quintero-Hernández V, Ortiz E, Rendón-Anaya M, Schwartz EF, Becerril B, Corzo G, Possani LD. Scorpion and spider venom peptides: gene cloning and peptide expression. Toxicon 2011; 58:644-63. [PMID: 21978889 DOI: 10.1016/j.toxicon.2011.09.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/08/2011] [Accepted: 09/22/2011] [Indexed: 01/05/2023]
Abstract
This communication reviews most of the important findings related to venom components isolated from scorpions and spiders, mainly by means of gene cloning and expression. Rather than revising results obtained by classical biochemical studies that report structure and function of venom components, here the emphasis is placed on cloning and identification of genes present in the venomous glands of these arachnids. Aspects related to cDNA library construction, specific or random ESTs cloning, transcriptome analysis, high-throughput screening, heterologous expression and folding are briefly discussed, showing some numbers of species and components already identified, but also shortly mentioning limitations and perspectives of research for the future in this field.
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Affiliation(s)
- V Quintero-Hernández
- Instituto de Biotecnología - UNAM, Avenida Universidad, Colonia Chamilpa, Cuernavaca, Morelos, Mexico
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Cloning and characterization of cDNA sequences encoding for new venom peptides of the Brazilian scorpion Opisthacanthus cayaporum. Toxicon 2009; 54:252-61. [PMID: 19379768 DOI: 10.1016/j.toxicon.2009.04.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 11/21/2022]
Abstract
Scorpion venom glands produce a large variety of bioactive peptides. This communication reports the identification of venom components obtained by sequencing clones isolated from a cDNA library prepared with venomous glands of the Brazilian scorpion Opisthacanthus cayaporum (Ischnuridae). Two main types of components were identified: peptides with toxin-like sequences and proteins involved in cellular processes. Using the expressed sequence tag (EST) strategy 118 clones were identified, from which 61 code for unique sequences (17 contigs and 44 singlets) with an average length of 531 base-pairs (bp). These results were compared with those previously obtained by the proteomic analysis of the same venom, showing a considerable degree of similarity in terms of the molecular masses expected and DNA sequences found. About 36% of the ESTs correspond to toxin-like peptides and proteins with identifiable open reading frames (ORFs). The cDNA sequencing results also show the presence of sequences whose putative products correspond to a scorpine-like component; three short antimicrobial peptides; three K(+)-channel blockers; and an additional peptide containing 78 amino acid residues, whose sequence resembles peptide La1 from another Ischnuridae scorpion Liocheles australiasiae, thus far with unknown function.
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12
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Schwartz EF, Capes EM, Diego-García E, Zamudio FZ, Fuentes O, Possani LD, Valdivia HH. Characterization of hadrucalcin, a peptide from Hadrurus gertschi scorpion venom with pharmacological activity on ryanodine receptors. Br J Pharmacol 2009; 157:392-403. [PMID: 19389159 DOI: 10.1111/j.1476-5381.2009.00147.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Members of the calcin family, presently including imperatoxin A, maurocalcin, opicalcins and hemicalcin, are basic, 33-mer peptide activators of ryanodine receptors (RyRs), the calcium channels of the sarcoplasmic reticulum (SR) that provide the majority of calcium for muscle contraction. Here we describe hadrucalcin, a novel member of this family. EXPERIMENTAL APPROACH Hadrucalcin was isolated from the venom of Hadrurus gertschi. Amino acid sequence and mass were determined by Edman degradation and mass spectrometry respectively. A cDNA library was constructed to generate clones for DNA sequence determination. Biological activity of native toxin was confirmed with [(3)H]ryanodine binding, by using SR vesicles from cardiac and skeletal muscle, and with single skeletal (RyR1) and cardiac (RyR2) channels reconstituted in lipid bilayers. Hadrucalcin was applied to intact ventricular myocytes to investigate effects on calcium transients. The secondary structure of hadrucalcin was computer-modelled by using atomic coordinates from maurocalcin, a structurally similar peptide. KEY RESULTS Hadrucalcin is distinguished from previously described congeners by two additional amino acids in its primary sequence and the lack of prominent amphipathicity. Hadrucalcin activated RyRs with high affinity (EC(50)= 37 nmol.L(-1)), induced a long-lasting subconductance state on RyR1 and RyR2, and rapidly (lag time approximately 2 s) penetrated ventricular cardiomyocytes, eliciting discharge of internal calcium stores and spontaneous contractions. CONCLUSIONS AND IMPLICATIONS Hadrucalcin is a cell-permeant, powerful activator of RyRs, which has translational potential for targeted delivery of drugs to RyR as novel therapeutic intervention in arrhythmogenic disease.
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Affiliation(s)
- Elisabeth F Schwartz
- Department of Physiological Sciences, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil
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Srairi-Abid N, Shahbazzadeh D, Chatti I, Mlayah-Bellalouna S, Mejdoub H, Borchani L, Benkhalifa R, Akbari A, El Ayeb M. Hemitoxin, the first potassium channel toxin from the venom of the Iranian scorpion Hemiscorpius lepturus. FEBS J 2008; 275:4641-50. [DOI: 10.1111/j.1742-4658.2008.06607.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Mass spectrometry analysis, amino acid sequence and biological activity of venom components from the Brazilian scorpion Opisthacanthus cayaporum. Toxicon 2008; 51:1499-508. [DOI: 10.1016/j.toxicon.2008.03.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 03/28/2008] [Accepted: 03/31/2008] [Indexed: 11/17/2022]
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15
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Transcriptome analysis of the venom gland of the Mexican scorpion Hadrurus gertschi (Arachnida: Scorpiones). BMC Genomics 2007; 8:119. [PMID: 17506894 PMCID: PMC1904202 DOI: 10.1186/1471-2164-8-119] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2007] [Accepted: 05/16/2007] [Indexed: 11/19/2022] Open
Abstract
Background Scorpions like other venomous animals posses a highly specialized organ that produces, secretes and disposes the venom components. In these animals, the last postabdominal segment, named telson, contains a pair of venomous glands connected to the stinger. The isolation of numerous scorpion toxins, along with cDNA-based gene cloning and, more recently, proteomic analyses have provided us with a large collection of venom components sequences. However, all of them are secreted, or at least are predicted to be secretable gene products. Therefore very little is known about the cellular processes that normally take place inside the glands for production of the venom mixture. To gain insights into the scorpion venom gland biology, we have decided to perform a transcriptomic analysis by constructing a cDNA library and conducting a random sequencing screening of the transcripts. Results From the cDNA library prepared from a single venom gland of the scorpion Hadrurus gertschi, 160 expressed sequence tags (ESTs) were analyzed. These transcripts were further clustered into 68 unique sequences (20 contigs and 48 singlets), with an average length of 919 bp. Half of the ESTs can be confidentially assigned as homologues of annotated gene products. Annotation of these ESTs, with the aid of Gene Ontology terms and homology to eukaryotic orthologous groups, reveals some cellular processes important for venom gland function; including high protein synthesis, tuned posttranslational processing and trafficking. Nonetheless, the main group of the identified gene products includes ESTs similar to known scorpion toxins or other previously characterized scorpion venom components, which account for nearly 60% of the identified proteins. Conclusion To the best of our knowledge this report contains the first transcriptome analysis of genes transcribed by the venomous gland of a scorpion. The data were obtained for the species Hadrurus gertschi, belonging to the family Caraboctonidae. One hundred and sixty ESTs were analyzed, showing enrichment in genes that encode for products similar to known venom components, but also provides the first sketch of cellular components, molecular functions, biological processes and some unique sequences of the scorpion venom gland.
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