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Yap MKK, Fung SY, Tan KY, Tan NH. Proteomic characterization of venom of the medically important Southeast Asian Naja sumatrana (Equatorial spitting cobra). Acta Trop 2014; 133:15-25. [PMID: 24508616 DOI: 10.1016/j.actatropica.2014.01.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/19/2014] [Accepted: 01/30/2014] [Indexed: 10/25/2022]
Abstract
The proteome of Naja sumatrana (Equatorial spitting cobra) venom was investigated by shotgun analysis and a combination of ion-exchange chromatography and reverse phase HPLC. Shotgun analysis revealed the presence of 39 proteins in the venom while the chromatographic approach identified 37 venom proteins. The results indicated that, like other Asiatic cobra venoms, N. sumatrana contains large number of three finger toxins and phospholipases A2, which together constitute 92.1% by weight of venom protein. However, only eight of the toxins can be considered as major venom toxins. These include two phospholipases A2, three neurotoxins (two long neurotoxins and a short neurotoxin) and three cardiotoxins. The eight major toxins have relative abundance of 1.6-27.2% venom proteins and together account for 89.8% (by weight) of total venom protein. Other venom proteins identified include Zn-metalloproteinase-disintegrin, Thaicobrin, CRISP, natriuretic peptide, complement depleting factors, cobra venom factors, venom nerve growth factor and cobra serum albumin. The proteome of N. sumatrana venom is similar to proteome of other Asiatic cobra venoms but differs from that of African spitting cobra venom. Our results confirm that the main toxic action of N. sumatrana venom is neurotoxic but the large amount of cardiotoxins and phospholipases A2 are likely to contribute significantly to the overall pathophysiological action of the venom. The differences in toxin distribution between N. sumatrana venom and African spitting cobra venoms suggest possible differences in the pathophysiological actions of N. sumatrana venom and the African spitting cobra venoms, and explain why antivenom raised against Asiatic cobra venom is not effective against African spitting cobra venoms.
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Lomonte B, Pla D, Sasa M, Tsai WC, Solórzano A, Ureña-Díaz JM, Fernández-Montes ML, Mora-Obando D, Sanz L, Gutiérrez JM, Calvete JJ. Two color morphs of the pelagic yellow-bellied sea snake, Pelamis platura, from different locations of Costa Rica: snake venomics, toxicity, and neutralization by antivenom. J Proteomics 2014; 103:137-52. [PMID: 24704853 DOI: 10.1016/j.jprot.2014.03.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 03/24/2014] [Accepted: 03/25/2014] [Indexed: 11/17/2022]
Abstract
UNLABELLED The yellow-bellied sea snake, Pelamis platura, is the most broadly distributed snake species. Despite being endowed with a highly lethal venom, a proteomic analysis of its toxin composition was unavailable. The venoms of specimens collected in Golfo de Papagayo and Golfo Dulce (Costa Rica), where two distinctive color morphs occur, were chromatographically compared. The latter inhabits a fjord-like gulf where the transit of oceanic sea snakes into and from the basin is restricted, thus possibly affecting gene flow. RP-HPLC evidenced a conserved venom protein profile in both populations, despite their divergent color phenotypes. Following a trend observed in other sea snakes, P. platura venom is relatively simple, being composed of proteins of the three-finger toxin (3FTx), phospholipase A2 (PLA2), cysteine-rich secretory protein (CRISP), 5'-nucleotidase, and metalloproteinase families. The first three groups represent 49.9%, 32.9%, and 9.1% of total venom protein, respectively. The most abundant component (~26%) is pelamitoxin (P62388), a short-chain 3FTx, followed by a major basic PLA2 (~20%) and a group of three isoforms of CRISPs (~9%). Whereas isolated pelamitoxin was highly lethal to mice, neither the PLA2 nor the CRISP fraction caused death. However, the PLA2 rapidly increased plasma creatine kinase activity after intramuscular injection, indicating its myotoxic action. Differing from myotoxic PLA2s of viperids, this PLA2 was not cytolytic to murine myogenic cells in vitro, suggesting possible differences in its mechanism of action. The median lethal dose (LD50) estimates for P. platura crude venom in mice and in three species of fishes did not differ significantly. The sea snake antivenom manufactured by CSL Ltd. (Australia), which uses Enhydrina schistosa as immunogen, cross-recognized the three major components of P. platura venom and, accordingly, neutralized the lethal activity of crude venom and pelamitoxin, therefore being of potential usefulness in the treatment of envenomations by this species. BIOLOGICAL SIGNIFICANCE Integrative analyses of animal venoms that combine the power of proteomics (venomics) with the characterization of their functional and immunological properties are significantly expanding knowledge on these remarkable bioweapons, both from a basic and a medical perspective. Costa Rica harbors a unique population of the yellow-bellied sea snake, Pelamis platura, that is restricted to a fjord-like gulf (Golfo Dulce). This population differs markedly from oceanic populations found elsewhere along the Pacific coast of this country, by presenting a patternless bright yellow coloration, instead of the typical bicolored or tricolored pattern of this species. It has been suggested that the dominance of this yellow-morph in Golfo Dulce might reflect gene flow restrictions, caused by the oceanographic conditions at this location. The present study demonstrates that the remarkable phenotypic variation between the two color morphs inhabiting Golfo Dulce and Golfo de Papagayo, respectively, is not associated with differences in the expression of venom components, as shown by their conserved RP-HPLC profiles. Proteomic analysis revealed the relatively simple toxin composition of P. platura venom, which contains three predominant types of proteins: three-finger toxins (protein abundance: 49.9%), phospholipases A2 (32.9%), and cysteine-rich secretory proteins (9.1%), together with few minor components. Further, the involvement of these most abundant proteins in the toxic effects of the venom, and their cross-recognition and neutralization by a sea snake antivenom produced against the venom of Enhydrina schistosa, were analyzed.
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Affiliation(s)
- Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica.
| | - Davinia Pla
- Instituto de Biomedicina de Valencia, CSIC, Jaume Roig 11, 46010 Valencia, Spain
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | - Wan-Chih Tsai
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | | | - Juan Manuel Ureña-Díaz
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | | | - Diana Mora-Obando
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | - Libia Sanz
- Instituto de Biomedicina de Valencia, CSIC, Jaume Roig 11, 46010 Valencia, Spain
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | - Juan J Calvete
- Instituto de Biomedicina de Valencia, CSIC, Jaume Roig 11, 46010 Valencia, Spain.
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153
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Calvete JJ. Next-generation snake venomics: protein-locus resolution through venom proteome decomplexation. Expert Rev Proteomics 2014; 11:315-29. [PMID: 24678852 DOI: 10.1586/14789450.2014.900447] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Venom research has been continuously enhanced by technological advances. High-throughput technologies are changing the classical paradigm of hypothesis-driven research to technology-driven approaches. However, the thesis advocated in this paper is that full proteome coverage at locus-specific resolution requires integrating the best of both worlds into a protocol that includes decomplexation of the venom proteome prior to liquid chromatography-tandem mass spectrometry matching against a species-specific transcriptome. This approach offers the possibility of proof-checking the species-specific contig database using proteomics data. Immunoaffinity chromatography constitutes the basis of an antivenomics workflow designed to quantify the extent of cross-reactivity of antivenoms against homologous and heterologous venom toxins. In the author's view, snake venomics and antivenomics form part of a biology-driven conceptual framework to unveil the genesis and natural history of venoms, and their within- and between-species toxicological and immunological divergences and similarities. Understanding evolutionary trends across venoms represents the Rosetta Stone for generating broad-ranging polyspecific antivenoms.
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Affiliation(s)
- Juan J Calvete
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Jaime Roig 11, 46010 Valencia, Spain +34 963 391 778 +34 963 690 800
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154
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Wang W, Chen QF, Yin RX, Zhu JJ, Li QB, Chang HH, Wu YB, Michelson E. Clinical features and treatment experience: a review of 292 Chinese cobra snakebites. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:648-655. [PMID: 24577231 DOI: 10.1016/j.etap.2013.12.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/20/2013] [Accepted: 12/30/2013] [Indexed: 06/03/2023]
Abstract
Although Chinese cobra snakebite is the most common type of snake venenation in China, it still lacks a comprehensive and systematic description. Hence, we aimed to study Chinese cobra bite cases with particular attention to demography, epidemiology and clinical profile. In this study, a total of 292 cases of Chinese cobra snakebite, presenting between January 1, 2008 and December 31, 2012, were retrospectively reviewed. To investigate the effect of treatment at different presentation times (time from snakebite to admission), the patients were divided into two groups: group A included 133 cases that presented <12 h after the bite; group B included 159 cases that presented ≥12 h after the bite. To assess the correlation between application of a tourniquet and skin grafting, the cases were re-divided into two groups according to whether or not a tourniquet was used after the snakebite: tourniquet group (n=220) and non-tourniquet group (n=72). The results showed that Chinese cobra snakebites were most commonly seen during the summer, in the upper limbs, and in males, young adults, and snake-hunters. Group A experienced milder intoxication than group B (P<0.001). The rate of skin grafting was significantly higher in the tourniquet group (20.0%, compared with 9.7% in the non-tourniquet group, P<0.05). The results of this study indicate that anti-cobra venom and swift admission (within 12 h of the snakebite) are recommended for Chinese cobra snakebite. Tourniquet use is not recommended.
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Affiliation(s)
- Wei Wang
- Department of Emergency, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Quan-Fang Chen
- Department of Respiratory, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Rui-Xing Yin
- Department of Cardiology, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Ji-Jin Zhu
- Department of Emergency, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Qi-Bin Li
- Department of Emergency, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Hai-Hua Chang
- Department of Emergency, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Yan-Bi Wu
- Department of Respiratory, the First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Edward Michelson
- Department of Emergency, University Hospitals Case Medical Center, Case Western Reserve University, 11100 Euclid Avenue, Cleveland, 44106 OH, USA.
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155
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Munawar A, Trusch M, Georgieva D, Hildebrand D, Kwiatkowski M, Behnken H, Harder S, Arni R, Spencer P, Schlüter H, Betzel C. Elapid snake venom analyses show the specificity of the peptide composition at the level of genera Naja and Notechis. Toxins (Basel) 2014; 6:850-68. [PMID: 24590383 PMCID: PMC3968365 DOI: 10.3390/toxins6030850] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/24/2014] [Accepted: 02/05/2014] [Indexed: 01/29/2023] Open
Abstract
Elapid snake venom is a highly valuable, but till now mainly unexplored, source of pharmacologically important peptides. We analyzed the peptide fractions with molecular masses up to 10 kDa of two elapid snake venoms—that of the African cobra, N. m. mossambica (genus Naja), and the Peninsula tiger snake, N. scutatus, from Kangaroo Island (genus Notechis). A combination of chromatographic methods was used to isolate the peptides, which were characterized by combining complimentary mass spectrometric techniques. Comparative analysis of the peptide compositions of two venoms showed specificity at the genus level. Three-finger (3-F) cytotoxins, bradykinin-potentiating peptides (BPPs) and a bradykinin inhibitor were isolated from the Naja venom. 3-F neurotoxins, Kunitz/basic pancreatic trypsin inhibitor (BPTI)-type inhibitors and a natriuretic peptide were identified in the N. venom. The inhibiting activity of the peptides was confirmed in vitro with a selected array of proteases. Cytotoxin 1 (P01467) from the Naja venom might be involved in the disturbance of cellular processes by inhibiting the cell 20S-proteasome. A high degree of similarity between BPPs from elapid and viperid snake venoms was observed, suggesting that these molecules play a key role in snake venoms and also indicating that these peptides were recruited into the snake venom prior to the evolutionary divergence of the snakes.
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Affiliation(s)
- Aisha Munawar
- Laboratory of Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, c/o DESY, Notkestreet 85, Building 22a, Hamburg 22603, Germany.
| | - Maria Trusch
- Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg 20146, Germany.
| | - Dessislava Georgieva
- Laboratory of Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, c/o DESY, Notkestreet 85, Building 22a, Hamburg 22603, Germany.
| | - Diana Hildebrand
- Institute of Clinical Chemistry, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, Hamburg 20246, Germany.
| | - Marcel Kwiatkowski
- Institute of Clinical Chemistry, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, Hamburg 20246, Germany.
| | - Henning Behnken
- Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg 20146, Germany.
| | - Sönke Harder
- Institute of Clinical Chemistry, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, Hamburg 20246, Germany.
| | - Raghuvir Arni
- Department of Physics, IBILCE/UNESP, Rua Cristóvão Colombo 2265, São José do Rio Preto CEP 15054-000, SP Brazil.
| | - Patrick Spencer
- Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, Avenue Lineu Prestes 2242, São Paulo 05508-000, Brazil.
| | - Hartmut Schlüter
- Institute of Clinical Chemistry, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, Hamburg 20246, Germany.
| | - Christian Betzel
- Laboratory of Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, c/o DESY, Notkestreet 85, Building 22a, Hamburg 22603, Germany.
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156
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Gutiérrez JM, Lomonte B, Sanz L, Calvete JJ, Pla D. Immunological profile of antivenoms: preclinical analysis of the efficacy of a polyspecific antivenom through antivenomics and neutralization assays. J Proteomics 2014; 105:340-50. [PMID: 24583507 DOI: 10.1016/j.jprot.2014.02.021] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 02/16/2014] [Accepted: 02/18/2014] [Indexed: 11/20/2022]
Abstract
UNLABELLED Parenteral administration of animal-derived antivenoms constitutes the mainstay in the treatment of snakebite envenomings. Despite the fact that this therapy has been available for over a century, the detailed understanding of the neutralizing and immunoreactivity profiles of the majority of antivenoms is pending. Currently, a combination of preclinical neutralization tests and 'antivenomics', i.e. a proteomic-based assessment of antivenom immunoreactivity, provides a powerful analytical platform to investigate the preclinical efficacy of antivenoms. In this review, the studies performed on the polyvalent antivenom manufactured by Instituto Clodomiro Picado, Costa Rica, are summarized. This antivenom is prepared by immunizing horses with a mixture of the venoms of Bothrops asper, Crotalus simus and Lachesis stenophrys, and is used in Central America for the treatment of envenomings by viperid species. Overall, the antivenom shows a widespread pattern of immunological reactivity against homologous and heterologous venoms, which correlates with its ability to neutralize lethal, hemorrhagic, myotoxic, coagulant, defibrinogenating, phospholipase A2 and proteinase activities of viperid venoms. At the same time, antivenomics detected several venom components against which the antivenom shows only partial or negligible immunorecognition, such as low molecular mass vasoactive peptides, disintegrins, and some phospholipases A2, P-I metalloproteinases and serine proteinases. Such information can be used to design strategies for enhancing the antibody response of horses against poorly immunogenic, toxicologically-relevant venom components in order to further improve the efficacy of this antivenom. BIOLOGICAL SIGNIFICANCE The timely parenteral administration of an appropriate antivenom remains, more than a century after the development of the first serum antivenimeux by Calmette and Phisalix and Bertrand, the only currently effective treatment for snakebite envenomings. A key technical issue in the generation of novel antivenoms is the design of optimized immunization venom mixtures that ensure that the resulting antidotes will be effective against the highest number of venoms from snakes of medical concern across the geographical range where they will be used. Antivenomics is a proteomics-based protocol developed to complement in vitro and in vivo standard preclinical tests in the qualitative and quantitative characterization of the immunological profile and the extent of cross-reactivity of antivenoms against homologous and heterologous venoms. Antivenomics is translational venomics. The combination of antivenomics and neutralization assays represents a powerful analytical platform to investigate the efficacy of antivenoms at the molecular and preclinical levels. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
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Affiliation(s)
- José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Libia Sanz
- Instituto de Biomedicina de Valencia, CSIC, Spain
| | | | - Davinia Pla
- Instituto de Biomedicina de Valencia, CSIC, Spain.
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157
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Gao JF, Wang J, He Y, Qu YF, Lin LH, Ma XM, Ji X. Proteomic and biochemical analyses of short-tailed pit viper (Gloydius brevicaudus) venom: age-related variation and composition-activity correlation. J Proteomics 2014; 105:307-22. [PMID: 24487038 DOI: 10.1016/j.jprot.2014.01.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/11/2014] [Accepted: 01/15/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED We conducted an in-depth analysis of the proteomic and biochemical profiles of the venom of neonate and adult short-tailed pit vipers (Gloydius brevicaudus). Identified proteins were assigned to a few main toxin families. Disintegrin, phospholipase A2 (PLA2), serine proteinase, cysteine-rich secretory protein, C-type lectin-like protein, l-amino acid oxidase and snake venom metalloproteinase (SVMP) were detected in both venoms, while 5'-nucleotidase was detected only in the adult venom. SVMP was the predominant protein family in both venoms (neonate: 65.7%; adult: 64.4%), followed by PLA2 (neonate: 13.4%; adult: 25.0%). Antivenomic analysis revealed that commercial G. brevicaudus antivenom almost neutralized the chromatographic peaks with medium and high molecular masses in both venoms, but did not completely recognize peaks with low molecular mass. Toxicological and enzymatic activities show remarkable age-related variation in G. brevicaudus venom, probably resulting from variation in venom composition. Our data demonstrate age-related variation across venomics, antivenomics and biochemical profiles of G. brevicaudus venom, and have implications for the management of G. brevicaudus bites, including improving antivenom preparation by combining both venoms. BIOLOGICAL SIGNIFICANCE This study investigates the composition and biochemical activity of neonate and adult Gloydius brevicaudus venoms. We found remarkable age-related variation in venom biological activity, likely the result of variation in venom composition. Antivenomics analysis was used to explore difference in neonate and adult G. brevicaudus venoms. Our findings have implications for the diagnosis and clinical management of G. brevicaudus bites, and the design of venom mixtures that will increase the efficacy of commercial antivenom. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
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Affiliation(s)
- Jian-Fang Gao
- Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
| | - Jin Wang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, Jiangsu, China
| | - Ying He
- Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
| | - Yan-Fu Qu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, Jiangsu, China
| | - Long-Hui Lin
- Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
| | - Xiao-Mei Ma
- Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
| | - Xiang Ji
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, Jiangsu, China.
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158
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Snake venomics: From the inventory of toxins to biology. Toxicon 2013; 75:44-62. [DOI: 10.1016/j.toxicon.2013.03.020] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/06/2013] [Accepted: 03/13/2013] [Indexed: 01/05/2023]
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159
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Otvos RA, Heus F, Vonk FJ, Halff J, Bruyneel B, Paliukhovich I, Smit AB, Niessen WM, Kool J. Analytical workflow for rapid screening and purification of bioactives from venom proteomes. Toxicon 2013; 76:270-81. [DOI: 10.1016/j.toxicon.2013.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/07/2013] [Accepted: 10/08/2013] [Indexed: 01/15/2023]
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160
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Habib AG. Public health aspects of snakebite care in West Africa: perspectives from Nigeria. J Venom Anim Toxins Incl Trop Dis 2013; 19:27. [PMID: 24134780 PMCID: PMC3831819 DOI: 10.1186/1678-9199-19-27] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 10/07/2013] [Indexed: 11/10/2022] Open
Abstract
Snakebite envenoming is a major public health problem among rural communities of the Nigerian savanna. The saw-scaled or carpet viper (Echis ocellatus) and, to a lesser extent, the African cobras (Naja spp.) and puff adders (Bitis arietans) have proved to be the most important cause of mortality and morbidity. The main clinical features of E. ocellatus envenoming are systemic hemorrhage, incoagulable blood, shock, local swelling, bleeding and, occasionally, necrosis. Bites may be complicated by amputation, blindness, disability, disfigurement, mutilation, tissue destruction and psychological consequences. Antivenom remains the hallmark and mainstay of envenoming management while studies in Nigeria confirm its protection of over 80% against mortality from carpet-viper bites. However, the availability, distribution and utilization of antivenom remain challenging although two new antivenoms (monospecific EchiTab G and trispecific EchiTab ICP-Plus) derived from Nigerian snake venoms have proven very effective and safe in clinical trials. A hub-and-spoke strategy is suggested for broadening antivenom access to endemic rural areas together with instituting quality assurance, standardization and manpower training. With the advent of antivenomics, national health authorities must be aided in selecting and purchasing antivenoms appropriate to their national needs while manufacturers should be helped in practical ways to improve the safety, efficacy and potential coverage against snake venoms and pricing of their products.
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Affiliation(s)
- Abdulrazaq G Habib
- Infectious and Tropical Diseases Unit, Bayero University Kano, Kano, Nigeria.
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161
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Assessing the preclinical efficacy of antivenoms: From the lethality neutralization assay to antivenomics. Toxicon 2013. [DOI: 10.1016/j.toxicon.2012.11.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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162
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Ali SA, Yang DC, Jackson TNW, Undheim EAB, Koludarov I, Wood K, Jones A, Hodgson WC, McCarthy S, Ruder T, Fry BG. Venom proteomic characterization and relative antivenom neutralization of two medically important Pakistani elapid snakes (Bungarus sindanus and Naja naja). J Proteomics 2013; 89:15-23. [PMID: 23714137 DOI: 10.1016/j.jprot.2013.05.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/01/2013] [Accepted: 05/06/2013] [Indexed: 11/17/2022]
Abstract
UNLABELLED Intra- and interspecific variation in venom composition has been shown to have a major effect upon the efficacy of antivenoms. Due to the absence of domestically produced antivenoms, Pakistan is wholly reliant upon antivenoms produced in other countries, such as India. However, the efficacy of these antivenoms in neutralising the venoms of Pakistani snakes has not been ascertained. This is symptomatic of the general state of toxicological research in this country, which has a myriad of highly toxic and medically important venomous animals. Thus, there is a dire need for knowledge regarding the fundamental proteomics of these venoms and applied knowledge of the relative efficacy of foreign antivenoms. Here we present the results of our proteomic research on two medically important snakes of Pakistan: Bungarus sindanus and Naja naja. Indian Polyvalent Antivenom (Bharat Serums and Vaccines Ltd), which is currently marketed for use in Pakistan, was completely ineffective against either Pakistani species. In addition to the expected pre- and post-synaptic neurotoxic activity, the venom of the Pakistan population of N. naja was shown to be quite divergent from other populations of this species in being potently myotoxic. These results highlight the importance of studying divergent species and isolated populations, where the same data not only elucidates clinical problems in need of immediate attention, but also uncovers sources for novel toxins with potentially useful activities. BIOLOGICAL SIGNIFICANCE Pakistan Bungarus sindanus and Naja naja venoms are differentially complex. Naja naja is potently myotoxic. Neither venom is neutralized by Indian antivenom. These results have direct implications for the treatment of envenomed patients in Pakistan. The unusually myotoxic effects of Naja naja demonstrates the value of studying remote populations for biodiscovery.
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Affiliation(s)
- Syed A Ali
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, Qld 4072, Australia
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Antivenom therapy of carpet viper (Echis ocellatus) envenoming: effectiveness and strategies for delivery in West Africa. Toxicon 2013; 69:82-9. [PMID: 23339853 DOI: 10.1016/j.toxicon.2013.01.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 12/29/2012] [Accepted: 01/03/2013] [Indexed: 11/23/2022]
Abstract
In West Africa, response to specific, geographically appropriate, antivenom is often dramatic following carpet viper (Echis ocellatus) envenoming with rapid restoration of blood coagulability and resolution of spontaneous haemorrhage. Envenoming from Australasian snakes causing similar coagulopathies may respond less dramatically and the effectiveness of antivenom is being questioned. Here we have reviewed and re-analysed all published preclinical and clinical studies on envenoming and antivenom therapy conducted in West Africa to determine the effectiveness of antivenom. 22 studies provided relevant information: 12 observational studies, 4 RCTs and 6 preclinical studies. Four comparative studies confirmed statistically significant protection against mortality ranging from 57 to 87% using specific antivenoms compared to non-specific or no antivenoms. Meta-analysis estimated combined Odds Ratio (95% CI) of 0.25 (0.14-0.45) of dying among those treated with specific antivenom or 75% (95% CI: 55-86%) protection against death. Mortality more than doubled during times when stocks of reliable antivenoms ran out, with Relative Risk (95% CI)] of 2.33 (1.26-4.06). Serum kinetics of venom antigen/antivenom levels also confirmed that decline of venom antigen levels coincided with resolution of coagulopathy while decline of antivenom levels was associated with venom antigen reappearance and recurrence of coagulopathy. Preclinical and antivenomics analysis confirmed efficacy of regionally appropriate antivenoms against E. ocellatus and related species' venoms in Sub-Saharan Africa but not against Asian Echis carinatus venom. Antivenoms raised against E. carinatus were ineffective in human studies. In West Africa, specific antivenom is effective in managing carpet viper envenoming. A centralized hub-and-spoke strategy is suggested for broadening antivenom access to endemic rural areas together with instituting quality assurance, standardization and manpower training. Benefits, risks, cost-effectiveness and feasibility of the approach should be formally assessed.
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164
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Brust A, Sunagar K, Undheim EAB, Vetter I, Yang DC, Yang DC, Casewell NR, Jackson TNW, Koludarov I, Alewood PF, Hodgson WC, Lewis RJ, King GF, Antunes A, Hendrikx I, Fry BG. Differential evolution and neofunctionalization of snake venom metalloprotease domains. Mol Cell Proteomics 2012; 12:651-63. [PMID: 23242553 DOI: 10.1074/mcp.m112.023135] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Snake venom metalloproteases (SVMP) are composed of five domains: signal peptide, propeptide, metalloprotease, disintegrin, and cysteine-rich. Secreted toxins are typically combinatorial variations of the latter three domains. The SVMP-encoding genes of Psammophis mossambicus venom are unique in containing only the signal and propeptide domains. We show that the Psammophis SVMP propeptide evolves rapidly and is subject to a high degree of positive selection. Unlike Psammophis, some species of Echis express both the typical multidomain and the unusual monodomain (propeptide only) SVMP, with the result that a lower level of variation is exerted upon the latter. We showed that most mutations in the multidomain Echis SVMP occurred in the protease domain responsible for proteolytic and hemorrhagic activities. The cysteine-rich and disintegrin-like domains, which are putatively responsible for making the P-III SVMPs more potent than the P-I and P-II forms, accumulate the remaining variation. Thus, the binding sites on the molecule's surface are evolving rapidly whereas the core remains relatively conserved. Bioassays conducted on two post-translationally cleaved novel proline-rich peptides from the P. mossambicus propeptide domain showed them to have been neofunctionalized for specific inhibition of mammalian a7 neuronal nicotinic acetylcholine receptors. We show that the proline rich postsynaptic specific neurotoxic peptides from Azemiops feae are the result of convergent evolution within the precursor region of the C-type natriuretic peptide instead of the SVMP. The results of this study reinforce the value of studying obscure venoms for biodiscovery of novel investigational ligands.
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Affiliation(s)
- Andreas Brust
- ‡Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
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165
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Leong PK, Tan NH, Fung SY, Sim SM. Cross neutralisation of Southeast Asian cobra and krait venoms by Indian polyvalent antivenoms. Trans R Soc Trop Med Hyg 2012; 106:731-7. [DOI: 10.1016/j.trstmh.2012.07.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 07/16/2012] [Accepted: 07/16/2012] [Indexed: 11/25/2022] Open
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166
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Abstract
Research is discussed in the areas of venomous snake taxonomy, epidemiology, species diagnosis, defining the clinical phenotype of human envenoming, pathophysiological mechanisms of envenoming, clinical testing of antivenoms and prevention of snake-bite through community education. This work was carried out over the past 40 years in many countries in four tropical continents. The help and friendship of a large number of collaborators is gratefully acknowledged.
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Affiliation(s)
- David A Warrell
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom.
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167
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Abstract
Recent proteomic analyses of snake venoms show that metalloproteinases represent major components in most of the Crotalid and Viperid venoms. In this chapter we discuss the multiple activities of the SVMPs. In addition to hemorrhagic activity, members of the SVMP family also have fibrin(ogen)olytic activity, act as prothrombin activators, activate blood coagulation factor X, possess apoptotic activity, inhibit platelet aggregation, are pro-inflammatory and inactivate blood serine proteinase inhibitors. Clearly the SVMPs have multiple functions in addition to their well-known hemorrhagic activity. The realization that there are structural variations in the SVMPs and the early studies that led to their classification represents an important event in our understanding of the structural forms of the SVMPs. The SVMPs were subdivided into the P-I, P-II and P-III protein classes. The noticeable characteristic that distinguished the different classes was their size (molecular weight) differences and domain structure: Class I (P-I), the small SVMPs, have molecular masses of 20-30 kDa, contain only a pro domain and the proteinase domain; Class II (P-II), the medium size SVMPs, molecular masses of 30-60 kDa, contain the pro domain, proteinase domain and disintegrin domain; Class III (P-III), the large SVMPs, have molecular masses of 60-100 kDa, contain pro, proteinase, disintegrin-like and cysteine-rich domain structure. Another significant advance in the SVMP field was the characterization of the crystal structure of the first P-I class SVMP. The structures of other P-I SVMPs soon followed and the structures of P-III SVMPs have also been determined. The active site of the metalloproteinase domain has a consensus HEXXHXXGXXHD sequence and a Met-turn. The "Met-turn" structure contains a conserved Met residue that forms a hydrophobic basement for the three zinc-binding histidines in the consensus sequence.
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Affiliation(s)
- Francis S Markland
- University of Southern California, Keck School of Medicine, Cancer Research Laboratory #106, 1303 N. Mission Rd., Los Angeles, CA 90033, USA.
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168
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Pla D, Gutiérrez JM, Calvete JJ. Second generation snake antivenomics: Comparing immunoaffinity and immunodepletion protocols. Toxicon 2012; 60:688-99. [DOI: 10.1016/j.toxicon.2012.04.342] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/11/2012] [Accepted: 04/18/2012] [Indexed: 10/28/2022]
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169
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Calvete JJ, Ghezellou P, Paiva O, Matainaho T, Ghassempour A, Goudarzi H, Kraus F, Sanz L, Williams DJ. Snake venomics of two poorly known Hydrophiinae: Comparative proteomics of the venoms of terrestrial Toxicocalamus longissimus and marine Hydrophis cyanocinctus. J Proteomics 2012; 75:4091-101. [PMID: 22643073 DOI: 10.1016/j.jprot.2012.05.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 05/14/2012] [Accepted: 05/16/2012] [Indexed: 10/28/2022]
Abstract
The venom proteomes of Toxicocalamus longissimus and Hydrophis cyanocinctus, a fossorial and a marine species, respectively, of the Hydrophiinae genus of Elapidae, were investigated by Edman degradation of RP-HPLC isolated proteins, and de novo MS/MS sequencing of in-gel derived tryptic peptide ions. The toxin arsenal of T. longissimus is made up of 1-2 type-I PLA(2) molecules, which account for 6.5% of the venom proteins, a minor PIII-SVMP (1.4% of the venom toxins), and ~20 members of the 3FTx family comprising 92% of the venom proteome. Seventeen proteins (5 type-I PLA(2)s and 12 3FTxs) were found in the venom of H. cyanocinctus. Three-finger toxins and type-I PLA(2) proteins comprise, respectively, 81% and 19% of its venom proteome. The simplicity of the H. cyanocinctus venom proteome is highlighted by the fact that only 6 venom components (3 short-chain neurotoxins, two long-chain neurotoxins, and one PLA(2) molecule) exhibit relative abundances >5%. As expected from its high neurotoxin abundance, the LD(50) for mice of H. cyanocinctus venom was fairly low, 0.132μg/g (intravenous) and 0.172μg/g (intraperitoneal). Our data indicate that specialization towards a lethal cocktail of 3FTx and type-I PLA(2) molecules may represent a widely adopted trophic solution throughout the evolution of Elapidae. Our results also points to a minimization of the molecular diversity of the toxin arsenal of the marine snake Hydrophis cyanocinctus in comparison to the venom proteome of its terrestrial relatives, and highlight that the same evolutionary solution, economy of the toxin arsenal, has been convergently adopted by different taxa in response to opposite selective pressures, loss and gain of neurotoxicity.
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Affiliation(s)
- Juan J Calvete
- Consejo Superior de Investigaciones Científicas, Valencia, Spain.
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170
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Gutiérrez JM. Improving antivenom availability and accessibility: science, technology, and beyond. Toxicon 2012; 60:676-87. [PMID: 22781134 DOI: 10.1016/j.toxicon.2012.02.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 02/23/2012] [Indexed: 01/15/2023]
Abstract
Snakebite envenomings constitute a serious and neglected public health problem. Despite the fact that effective treatment exists, i.e. administration of animal-derived antivenoms, the availability and accessibility of these life-saving immunobiologicals is deficitary in various parts of the world, particularly in sub-Saharan Africa and some regions of Asia. This article discusses some of the problems that need to be circumvented in order to improve the availability and accessibility of antivenoms. The conglomerate of antivenom manufacturers is highly heterogeneous in terms of technological base, qualification of staff, implementation of Good Manufacturing Practices (GMPs), and volume of production. Therefore, improvements in antivenom quality and availability should be based on strategies tailored to the situation of each region or country; in this context, three different scenarios are discussed. Accessibility of antivenoms demands concerted efforts at multiple levels, including raising the awareness of public health authorities on the relevance of the problem, implementing innovative antivenom purchasing schemes, strengthening national distribution channels on the basis of robust epidemiological information, improving the cold chain and the provision of health services in remote rural settings, supporting the correct use of antivenoms, and promoting the involvement of local community organizations in various aspects of prevention and management. These tasks should be envisaged in terms of synergistic, interprogrammatic and intersectorial interventions, with the participation of many players.
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Affiliation(s)
- José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
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171
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Comparative study of the cytolytic activity of snake venoms from African spitting cobras (Naja spp., Elapidae) and its neutralization by a polyspecific antivenom. Toxicon 2011; 58:558-64. [DOI: 10.1016/j.toxicon.2011.08.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/26/2011] [Accepted: 08/30/2011] [Indexed: 10/17/2022]
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172
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Antihaemolytic and snake venom neutralizing effect of some Indian medicinal plants. ASIAN PAC J TROP MED 2011; 4:743-7. [DOI: 10.1016/s1995-7645(11)60185-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 07/11/2011] [Accepted: 07/25/2011] [Indexed: 11/20/2022] Open
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173
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Williams DJ, Gutiérrez JM, Calvete JJ, Wüster W, Ratanabanangkoon K, Paiva O, Brown NI, Casewell NR, Harrison RA, Rowley PD, O'Shea M, Jensen SD, Winkel KD, Warrell DA. Ending the drought: new strategies for improving the flow of affordable, effective antivenoms in Asia and Africa. J Proteomics 2011; 74:1735-67. [PMID: 21640209 DOI: 10.1016/j.jprot.2011.05.027] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 04/30/2011] [Accepted: 05/11/2011] [Indexed: 01/13/2023]
Abstract
The development of snake antivenoms more than a century ago should have heralded effective treatment of the scourge of snakebite envenoming in impoverished, mostly rural populations around the world. That snakebite still exists today, as a widely untreated illness that maims, kills and terrifies men, women and children in vulnerable communities, is a cruel anachronism. Antivenom can be an effective, safe and affordable treatment for snakebites, but apathy, inaction and the politicisation of public health have marginalised both the problem (making snakebite arguably the most neglected of all neglected tropical diseases) and its solution. For lack of any coordinated approach, provision of antivenoms has been pushed off the public health agenda, leading to an incongruous decline in demand for these crucial antidotes, excused and fed by new priorities, an absence of epidemiological data, and a poor regulatory framework. These factors facilitated the infiltration of poor quality products that degrade user confidence and undermine legitimate producers. The result is that tens of thousands are denied an essential life-saving medicine, allowing a toll of human suffering that is a summation of many individual catastrophes. No strategy has been developed to address this problem and to overcome the intransigence and inaction responsible for the global tragedy of snakebite. Attempts to engage with the broader public health community through the World Health Organisation (WHO), GAVI, and other agencies have failed. Consequently, the toxinology community has taken on a leadership role in a new approach, the Global Snakebite Initiative, which seeks to mobilise the resources, skills and experience of scientists and clinicians for whom venoms, toxins, antivenoms, snakes and snakebites are already fields of interest. Proteomics is one such discipline, which has embraced the potential of using venoms in bio-discovery and systems biology. The fields of venomics and antivenomics have recently evolved from this discipline, offering fresh hope for the victims of snakebites by providing an exciting insight into the complexities, nature, fundamental properties and significance of venom constituents. Such a rational approach brings with it the potential to design new immunising mixtures from which to raise potent antivenoms with wider therapeutic ranges. This addresses a major practical limitation in antivenom use recognised since the beginning of the 20th century: the restriction of therapeutic effectiveness to the specific venom immunogen used in production. Antivenomic techniques enable the interactions between venoms and antivenoms to be examined in detail, and if combined with functional assays of specific activity and followed up by clinical trials of effectiveness and safety, can be powerful tools with which to evaluate the suitability of current and new antivenoms for meeting urgent regional needs. We propose two mechanisms through which the Global Snakebite Initiative might seek to end the antivenom drought in Africa and Asia: first by establishing a multidisciplinary, multicentre, international collaboration to evaluate currently available antivenoms against the venoms of medically important snakes from specific nations in Africa and Asia using a combination of proteomic, antivenomic and WHO-endorsed preclinical assessment protocols, to provide a validated evidence base for either recommending or rejecting individual products; and secondly by bringing the power of proteomics to bear on the design of new immunising mixtures to raise Pan-African and Pan-Asian polyvalent antivenoms of improved potency and quality. These products will be subject to rigorous clinical assessment. We propose radically to change the basis upon which antivenoms are produced and supplied for the developing world. Donor funding and strategic public health alliances will be sought to make it possible not only to sustain the financial viability of antivenom production partnerships, but also to ensure that patients are relieved of the costs of antivenom so that poverty is no longer a barrier to the treatment of this important, but grossly neglected public health emergency.
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Affiliation(s)
- David J Williams
- Australian Venom Research Unit, Department of Pharmacology, University of Melbourne, Parkville, Vic, 3010, Australia.
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174
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Corrêa-Netto C, Junqueira-de-Azevedo IDLM, Silva DA, Ho PL, Leitão-de-Araújo M, Alves MLM, Sanz L, Foguel D, Zingali RB, Calvete JJ. Snake venomics and venom gland transcriptomic analysis of Brazilian coral snakes, Micrurus altirostris and M. corallinus. J Proteomics 2011; 74:1795-809. [PMID: 21515432 DOI: 10.1016/j.jprot.2011.04.003] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 04/01/2011] [Accepted: 04/04/2011] [Indexed: 11/26/2022]
Abstract
The venom proteomes of Micrurus altirostris and M. corallinus were analyzed by combining snake venomics and venom gland transcriptomic surveys. In both coral snake species, 3FTx and PLA(2) were the most abundant and diversified toxin families. 33 different 3FTxs and 13 PLA(2) proteins, accounting respectively for 79.5% and 13.7% of the total proteins, were identified in the venom of M. altirostris. The venom of M. corallinus comprised 10 3FTx (81.7% of the venom proteome) and 4 (11.9%) PLA(2) molecules. Transcriptomic data provided the full-length amino acid sequences of 18 (M. altirostris) and 10 (M. corallinus) 3FTxs, and 3 (M. altirostris) and 1 (M. corallinus) novel PLA(2) sequences. In addition, venom from each species contained single members of minor toxin families: 3 common (PIII-SVMP, C-type lectin-like, L-amino acid oxidase) and 4 species-specific (CRISP, Kunitz-type inhibitor, lysosomal acid lipase in M. altirostris; serine proteinase in M. corallinus) toxin classes. The finding of a lipase (LIPA) in the venom proteome and in the venom gland transcriptome of M. altirostris supports the view of a recruitment event predating the divergence of Elapidae and Viperidae more than 60 Mya. The toxin profile of both M. altirostris and M. corallinus venoms points to 3FTxs and PLA(2) molecules as the major players of the envenoming process. In M. altirostris venom, all major, and most minor, 3FTxs display highest similarity to type I α-neurotoxins, suggesting that these postsynaptically acting toxins may play the predominant role in the neurotoxic effect leading to peripheral paralysis, respiratory arrest, and death. M. corallinus venom posesses both, type I α-neurotoxins and a high-abundance (26% of the venom proteome) protein of subfamily XIX of 3FTxs, exhibiting similarity to bucandin from Malayan krait, Bungarus candidus, venom, which enhances acetylcholine release presynaptically. This finding may explain the presynaptic neurotoxicity of M. corallinus venom and the lack of this effect in M. altirostris venom. The anti-Micrurus (corallinus and frontalis) antivenom produced by Instituto Butantan quantitatively immunodepleted the minor toxins from M. altirostris and M. corallinus venoms but showed impaired crossreactivity towards their major 3FTx and PLA(2) molecules. The structural diversity of 3FTxs among Micrurus sp. may underlay the impaired cross-immunoreactivity of the Butantan antivenom towards M. altirostris and M. corallinus toxins, hampering the possibility to raise an antivenom against a simple venom mixture exhibiting paraspecific neutralization of other Micrurus venoms.
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Affiliation(s)
- Carlos Corrêa-Netto
- Instituto de Bioquímica Médica, Programa de Biologia Estrutural and Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Brazil
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