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Dynamic genetic differentiation drives the widespread structural and functional convergent evolution of snake venom proteinaceous toxins. BMC Biol 2022; 20:4. [PMID: 34996434 PMCID: PMC8742412 DOI: 10.1186/s12915-021-01208-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/06/2021] [Indexed: 12/25/2022] Open
Abstract
Background The explosive radiation and diversification of the advanced snakes (superfamily Colubroidea) was associated with changes in all aspects of the shared venom system. Morphological changes included the partitioning of the mixed ancestral glands into two discrete glands devoted for production of venom or mucous respectively, as well as changes in the location, size and structural elements of the venom-delivering teeth. Evidence also exists for homology among venom gland toxins expressed across the advanced snakes. However, despite the evolutionary novelty of snake venoms, in-depth toxin molecular evolutionary history reconstructions have been mostly limited to those types present in only two front-fanged snake families, Elapidae and Viperidae. To have a broader understanding of toxins shared among extant snakes, here we first sequenced the transcriptomes of eight taxonomically diverse rear-fanged species and four key viperid species and analysed major toxin types shared across the advanced snakes. Results Transcriptomes were constructed for the following families and species: Colubridae - Helicops leopardinus, Heterodon nasicus, Rhabdophis subminiatus; Homalopsidae – Homalopsis buccata; Lamprophiidae - Malpolon monspessulanus, Psammophis schokari, Psammophis subtaeniatus, Rhamphiophis oxyrhynchus; and Viperidae – Bitis atropos, Pseudocerastes urarachnoides, Tropidolaeumus subannulatus, Vipera transcaucasiana. These sequences were combined with those from available databases of other species in order to facilitate a robust reconstruction of the molecular evolutionary history of the key toxin classes present in the venom of the last common ancestor of the advanced snakes, and thus present across the full diversity of colubroid snake venoms. In addition to differential rates of evolution in toxin classes between the snake lineages, these analyses revealed multiple instances of previously unknown instances of structural and functional convergences. Structural convergences included: the evolution of new cysteines to form heteromeric complexes, such as within kunitz peptides (the beta-bungarotoxin trait evolving on at least two occasions) and within SVMP enzymes (the P-IIId trait evolving on at least three occasions); and the C-terminal tail evolving on two separate occasions within the C-type natriuretic peptides, to create structural and functional analogues of the ANP/BNP tailed condition. Also shown was that the de novo evolution of new post-translationally liberated toxin families within the natriuretic peptide gene propeptide region occurred on at least five occasions, with novel functions ranging from induction of hypotension to post-synaptic neurotoxicity. Functional convergences included the following: multiple occasions of SVMP neofunctionalised in procoagulant venoms into activators of the clotting factors prothrombin and Factor X; multiple instances in procoagulant venoms where kunitz peptides were neofunctionalised into inhibitors of the clot destroying enzyme plasmin, thereby prolonging the half-life of the clots formed by the clotting activating enzymatic toxins; and multiple occasions of kunitz peptides neofunctionalised into neurotoxins acting on presynaptic targets, including twice just within Bungarus venoms. Conclusions We found novel convergences in both structural and functional evolution of snake toxins. These results provide a detailed roadmap for future work to elucidate predator–prey evolutionary arms races, ascertain differential clinical pathologies, as well as documenting rich biodiscovery resources for lead compounds in the drug design and discovery pipeline. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01208-9.
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Slagboom J, Mladić M, Xie C, Kazandjian TD, Vonk F, Somsen GW, Casewell NR, Kool J. High throughput screening and identification of coagulopathic snake venom proteins and peptides using nanofractionation and proteomics approaches. PLoS Negl Trop Dis 2020; 14:e0007802. [PMID: 32236099 PMCID: PMC7153897 DOI: 10.1371/journal.pntd.0007802] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/13/2020] [Accepted: 03/01/2020] [Indexed: 11/19/2022] Open
Abstract
Snakebite is a neglected tropical disease that results in a variety of systemic and local pathologies in envenomed victims and is responsible for around 138,000 deaths every year. Many snake venoms cause severe coagulopathy that makes victims vulnerable to suffering life-threating haemorrhage. The mechanisms of action of coagulopathic snake venom toxins are diverse and can result in both anticoagulant and procoagulant effects. However, because snake venoms consist of a mixture of numerous protein and peptide components, high throughput characterizations of specific target bioactives is challenging. In this study, we applied a combination of analytical and pharmacological methods to identify snake venom toxins from a wide diversity of snake species that perturb coagulation. To do so, we used a high-throughput screening approach consisting of a miniaturised plasma coagulation assay in combination with a venom nanofractionation approach. Twenty snake venoms were first separated using reversed-phase liquid chromatography, and a post-column split allowed a small fraction to be analyzed with mass spectrometry, while the larger fraction was collected and dispensed onto 384-well plates. After fraction collection, any solvent present in the wells was removed by means of freeze-drying, after which it was possible to perform a plasma coagulation assay in order to detect coagulopathic activity. Our results demonstrate that many snake venoms simultaneously contain both procoagulant and anticoagulant bioactives that contribute to coagulopathy. In-depth identification analysis from seven medically-important venoms, via mass spectrometry and nanoLC-MS/MS, revealed that phospholipase A2 toxins are frequently identified in anticoagulant venom fractions, while serine protease and metalloproteinase toxins are often associated with procoagulant bioactivities. The nanofractionation and proteomics approach applied herein seems likely to be a valuable tool for the rational development of next-generation snakebite treatments by facilitating the rapid identification and fractionation of coagulopathic toxins, thereby enabling specific targeting of these toxins by new therapeutics such as monoclonal antibodies and small molecule inhibitors.
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Affiliation(s)
- Julien Slagboom
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules Medicines and Systems, VU University Amsterdam, Amsterdam, The Netherlands
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Marija Mladić
- Animal Sciences and Health, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Chunfang Xie
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules Medicines and Systems, VU University Amsterdam, Amsterdam, The Netherlands
| | - Taline D. Kazandjian
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Freek Vonk
- Naturalis Biodiversity Center, Leiden, The Netherlands
| | - Govert W. Somsen
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules Medicines and Systems, VU University Amsterdam, Amsterdam, The Netherlands
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jeroen Kool
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules Medicines and Systems, VU University Amsterdam, Amsterdam, The Netherlands
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Eble JA. Structurally Robust and Functionally Highly Versatile-C-Type Lectin (-Related) Proteins in Snake Venoms. Toxins (Basel) 2019; 11:toxins11030136. [PMID: 30823637 PMCID: PMC6468738 DOI: 10.3390/toxins11030136] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/31/2022] Open
Abstract
Snake venoms contain an astounding variety of different proteins. Among them are numerous C-type lectin family members, which are grouped into classical Ca2+- and sugar-binding lectins and the non-sugar-binding snake venom C-type lectin-related proteins (SV-CLRPs), also called snaclecs. Both groups share the robust C-type lectin domain (CTLD) fold but differ in a long loop, which either contributes to a sugar-binding site or is expanded into a loop-swapping heterodimerization domain between two CLRP subunits. Most C-type lectin (-related) proteins assemble in ordered supramolecular complexes with a high versatility of subunit numbers and geometric arrays. Similarly versatile is their ability to inhibit or block their target molecules as well as to agonistically stimulate or antagonistically blunt a cellular reaction triggered by their target receptor. By utilizing distinct interaction sites differentially, SV-CLRPs target a plethora of molecules, such as distinct coagulation factors and receptors of platelets and endothelial cells that are involved in hemostasis, thrombus formation, inflammation and hematogenous metastasis. Because of their robust structure and their high affinity towards their clinically relevant targets, SV-CLRPs are and will potentially be valuable prototypes to develop new diagnostic and therapeutic tools in medicine, provided that the molecular mechanisms underlying their versatility are disclosed.
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Affiliation(s)
- Johannes A Eble
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Waldeyerstr. 15, 48149 Münster, Germany.
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Pires WL, de Castro OB, Kayano AM, da Silva Setúbal S, Pontes AS, Nery NM, Paloschi MV, Dos Santos Pereira S, Stábeli RG, Fernandes CFC, Soares AM, Zuliani JP. Effect of BjcuL, a lectin isolated from Bothrops jararacussu, on human peripheral blood mononuclear cells. Toxicol In Vitro 2017; 41:30-41. [PMID: 28188836 DOI: 10.1016/j.tiv.2017.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/13/2017] [Accepted: 02/02/2017] [Indexed: 02/05/2023]
Abstract
BjcuL is a C-type lectin with specificity for the binding of β-d-galactose units isolated from Bothrops jararacussu venom. It triggers cellular infiltration in post capillary venules, increases edema and vascular permeability in murine models, contributes to in vitro neutrophil activation and modulates macrophage functional activation towards an M1 state. The purpose of this study was to investigate the effect of BjcuL on human peripheral blood mononuclear cells (PBMCs) activation with a focus on PBMCs proliferation and inflammatory mediators release. Results showed that BjcuL is not toxic to PBMCs, that BjcuL inhibits PBMCs proliferation and that it stimulates PBMCs to produce superoxide anion and hydrogen peroxide, primarily via lymphocyte stimulation, but does not stimulate the production of nitric oxide and PGE2. These results demonstrate that BjcuL has an immunomodulatory effect on PBMCs. Further studies are needed to confirm the immunomodulatory effect of BjcuL, to elucidate the molecular mechanisms of action responsible for its effects and to determine its potential application as an immunopharmacological and biotechnological tool.
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Affiliation(s)
- Weverson Luciano Pires
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Onassis Boeri de Castro
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Anderson Makoto Kayano
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil; Centro de Estudos de Biomoléculas Aplicadas à Saúde (CEBio), Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Departamento de Medicina, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil
| | - Sulamita da Silva Setúbal
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Adriana Silva Pontes
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Neriane Monteiro Nery
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Mauro Valentino Paloschi
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Soraya Dos Santos Pereira
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil
| | - Rodrigo Guerino Stábeli
- Centro de Estudos de Biomoléculas Aplicadas à Saúde (CEBio), Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Departamento de Medicina, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil
| | - Carla Freire Celedônio Fernandes
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil; Centro de Pesquisa em Medicina Tropical, Porto Velho, RO, Brazil
| | - Andreimar Martins Soares
- Centro de Estudos de Biomoléculas Aplicadas à Saúde (CEBio), Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Departamento de Medicina, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil
| | - Juliana Pavan Zuliani
- Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho, RO, Brazil; Centro de Estudos de Biomoléculas Aplicadas à Saúde (CEBio), Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Departamento de Medicina, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil.
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Sartim MA, Sampaio SV. Snake venom galactoside-binding lectins: a structural and functional overview. J Venom Anim Toxins Incl Trop Dis 2015; 21:35. [PMID: 26413085 PMCID: PMC4583214 DOI: 10.1186/s40409-015-0038-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 09/16/2015] [Indexed: 12/13/2022] Open
Abstract
Snake venom galactoside-binding lectins (SVgalLs) comprise a class of toxins capable of recognizing and interacting with terminal galactoside residues of glycans. In the past 35 years, since the first report on the purification of thrombolectin from Bothrops atrox snake venom, several SVgalLs from Viperidae and Elapidae snake families have been described, as has progressive improvement in the investigation of structural/functional aspects of these lectins. Moreover, the advances of techniques applied in protein-carbohydrate recognition have provided important approaches in order to screen for possible biological targets. The present review describes the efforts over the past 35 years to elucidate SVgalLs, highlighting their structure and carbohydrate recognition function involved in envenomation pathophysiology and potential biomedical applications.
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Affiliation(s)
- Marco A. Sartim
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil
| | - Suely V. Sampaio
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil
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Accary C, Rima M, Kouzahya A, Hleihel W, Sadek R, Desfontis JC, Fajloun Z, Hraoui-Bloquet S. Effect of the Montivipera bornmuelleri snake venom on human blood: coagulation disorders and hemolytic activities. ACTA ACUST UNITED AC 2014. [DOI: 10.13055/ojhmt_5_1_4.140609] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Castanheira LE, Nunes DCDO, Cardoso TM, Santos PDS, Goulart LR, Rodrigues RS, Richardson M, Borges MH, Yoneyama KAG, Rodrigues VM. Biochemical and functional characterization of a C-type lectin (BpLec) from Bothrops pauloensis snake venom. Int J Biol Macromol 2013. [DOI: 10.1016/j.ijbiomac.2012.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Antitumoral potential of Tunisian snake venoms secreted phospholipases A2. BIOMED RESEARCH INTERNATIONAL 2013; 2013:391389. [PMID: 23509718 PMCID: PMC3581298 DOI: 10.1155/2013/391389] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 09/04/2012] [Indexed: 11/17/2022]
Abstract
Phospholipases type A2 (PLA2s) are the most abundant proteins found in Viperidae snake venom. They are quite fascinating from both a biological and structural point of view. Despite similarity in their structures and common catalytic properties, they exhibit a wide spectrum of pharmacological activities. Besides being hydrolases, secreted phospholipases A2 (sPLA2) are an important group of toxins, whose action at the molecular level is still a matter of debate. These proteins can display toxic effects by different mechanisms. In addition to neurotoxicity, myotoxicity, hemolytic activity, antibacterial, anticoagulant, and antiplatelet effects, some venom PLA2s show antitumor and antiangiogenic activities by mechanisms independent of their enzymatic activity. This paper aims to discuss original finding against anti-tumor and anti-angiogenic activities of sPLA2 isolated from Tunisian vipers: Cerastes cerastes and Macrovipera lebetina, representing new tools to target specific integrins, mainly, α5β1 and αv integrins.
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9
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Rodrigues RS, Boldrini-França J, Fonseca FPP, de la Torre P, Henrique-Silva F, Sanz L, Calvete JJ, Rodrigues VM. Combined snake venomics and venom gland transcriptomic analysis of Bothropoides pauloensis. J Proteomics 2012; 75:2707-20. [PMID: 22480909 DOI: 10.1016/j.jprot.2012.03.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 10/28/2022]
Abstract
Unraveling the repertoire of venom toxins of Bothropoides pauloensis was assessed by snake venomics and venom gland transcriptomic surveys. Both approaches yielded converging overall figures, pointing to metalloproteinases (~37%), PLA(2)s (26-32%), and vasoactive (bradykinin-potentiating) peptides (12-17%) as the major toxin classes. The high occurrence of SVMPs, PLA(2) molecules, vasoactive peptides, along with serine proteinases, explains the local and systemic effects observed in envenomations by B. pauloensis. Minor (<3%) C-type lectin, serine proteinase, L-amino acid oxidase, nerve growth factor, and CRISP molecules were also identified in the transcriptome and the proteome. Low abundance (0.3%) EST singletons coding for vascular endothelial growth factor (svVEGF), ohanin, hyaluronidase, and 5' nucleotidase were found only in the venom gland cDNA library. At the molecular level, the transcriptomic and proteomic datasets display low compositional concordance. In particular, although there is good agreement between transcriptome and proteome in the identity of BPPs, PLA(2) molecules and L-amino acid oxidase, both datasets strongly depart in their C-type lectin and SVMP complements. These data support the view that venom composition is influenced by transcriptional and translational mechanisms and emphasize the value of combining proteomic and transcriptomic approaches to acquire a more complete understanding of the toxinological profile and natural history of the snake venom.
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Affiliation(s)
- Renata S Rodrigues
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil
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Darville LNF, Merchant ME, Maccha V, Siddavarapu VR, Hasan A, Murray KK. Isolation and determination of the primary structure of a lectin protein from the serum of the American alligator (Alligator mississippiensis). Comp Biochem Physiol B Biochem Mol Biol 2011; 161:161-9. [PMID: 22085437 DOI: 10.1016/j.cbpb.2011.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/01/2011] [Accepted: 11/02/2011] [Indexed: 10/15/2022]
Abstract
Mass spectrometry in conjunction with de novo sequencing was used to determine the amino acid sequence of a 35kDa lectin protein isolated from the serum of the American alligator that exhibits binding to mannose. The protein N-terminal sequence was determined using Edman degradation and enzymatic digestion with different proteases was used to generate peptide fragments for analysis by liquid chromatography tandem mass spectrometry (LC MS/MS). Separate analysis of the protein digests with multiple enzymes enhanced the protein sequence coverage. De novo sequencing was accomplished using MASCOT Distiller and PEAKS software and the sequences were searched against the NCBI database using MASCOT and BLAST to identify homologous peptides. MS analysis of the intact protein indicated that it is present primarily as monomer and dimer in vitro. The isolated 35kDa protein was ~98% sequenced and found to have 313 amino acids and nine cysteine residues and was identified as an alligator lectin. The alligator lectin sequence was aligned with other lectin sequences using DIALIGN and ClustalW software and was found to exhibit 58% and 59% similarity to both human and mouse intelectin-1. The alligator lectin exhibited strong binding affinities toward mannan and mannose as compared to other tested carbohydrates.
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Affiliation(s)
- Lancia N F Darville
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
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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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Nunes EDS, de Souza MAA, Vaz AFDM, Santana GMDS, Gomes FS, Coelho LCBB, Paiva PMG, da Silva RML, Silva-Lucca RA, Oliva MLV, Guarnieri MC, Correia MTDS. Purification of a lectin with antibacterial activity from Bothrops leucurus snake venom. Comp Biochem Physiol B Biochem Mol Biol 2011; 159:57-63. [DOI: 10.1016/j.cbpb.2011.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 02/07/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
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13
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Mendonça-Franqueiro EDP, Alves-Paiva RDM, Sartim MA, Callejon DR, Paiva HH, Antonucci GA, Rosa JC, Cintra ACO, Franco JJ, Arantes EC, Dias-Baruffi M, Sampaio SV. Isolation, functional, and partial biochemical characterization of galatrox, an acidic lectin from Bothrops atrox snake venom. Acta Biochim Biophys Sin (Shanghai) 2011; 43:181-92. [PMID: 21297119 DOI: 10.1093/abbs/gmr003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Snake venom lectins have been studied in regard to their chemical structure and biological functions. However, little is known about lectins isolated from Bothrops atrox snake venom. We report here the isolation and partial functional and biochemical characterization of an acidic glycan-binding protein called galatrox from this venom. This lectin was purified by affinity chromatography using a lactosyl-sepharose column, and its homogeneity and molecular mass were evaluated by high-performance liquid chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The purified galatrox was homogeneous and characterized as an acidic protein (pI 5.2) with a monomeric and dimeric molecular mass of 16.2 and 32.5 kDa, respectively. Alignment of N-terminal and internal amino acid sequences of galatrox indicated that this protein exhibits high homology to other C-type snake venom lectins. Galatrox showed optimal hemagglutinating activity at a concentration of 100 μg/ml and this effect was drastically inhibited by lactose, ethylenediaminetetraacetic acid, and heating, which confirmed galatrox's lectin activity. While galatrox failed to induce the same level of paw edema or mast cell degranulation as B. atrox crude venom, galatrox did alter cellular viability, which suggested that galatrox might contribute to venom toxicity by directly inducing cell death.
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Affiliation(s)
- Elaine de Paula Mendonça-Franqueiro
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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Earl STH, Robson J, Trabi M, de Jersey J, Masci PP, Lavin MF. Characterisation of a mannose-binding C-type lectin from Oxyuranus scutellatus snake venom. Biochimie 2010; 93:519-27. [PMID: 21115100 DOI: 10.1016/j.biochi.2010.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 11/17/2010] [Indexed: 11/17/2022]
Abstract
C-type lectins are calcium-dependent sugar binding proteins and are distributed ubiquitously amongst vertebrate organisms. As part of a wider study on Australian snake venom components, we have identified and characterised a C-type lectin from the venom of Oxyuranus scutellatus (Australian coastal taipan) with mannose-binding activity. This protein exhibited a subunit molecular mass of 15 kDa and was found to bind mannose and also bind to and agglutinate erythrocytes in a Ca(2+)-dependent manner. cDNA transcripts coding for C-lectin proteins were cloned and sequenced from six Australian elapid snake species and an antibody generated against the O. scutellatus mannose-binding C-lectin identified C-lectin proteins in the venom of 13 Australian elapid snakes by immunoblotting. Experimental evidence and molecular modelling also suggest that this protein exhibits a unique dimeric structure. This is the first confirmed example of a snake venom C-lectin with mannose-binding activity.
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Affiliation(s)
- Stephen T H Earl
- The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Australia
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Valente RH, Guimarães PR, Junqueira M, Neves-Ferreira AGC, Soares MR, Chapeaurouge A, Trugilho MR, León IR, Rocha SL, Oliveira-Carvalho AL, Wermelinger LS, Dutra DL, Leão LI, Junqueira-de-Azevedo IL, Ho PL, Zingali RB, Perales J, Domont GB. Bothrops insularis venomics: A proteomic analysis supported by transcriptomic-generated sequence data. J Proteomics 2009; 72:241-55. [DOI: 10.1016/j.jprot.2009.01.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/05/2009] [Accepted: 01/07/2009] [Indexed: 11/30/2022]
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Zelanis A, Travaglia-Cardoso SR, De Fátima Domingues Furtado M. Ontogenetic changes in the venom of Bothrops insularis (Serpentes: Viperidae)and its biological implication. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2008. [DOI: 10.2994/1808-9798(2008)3[43:ocitvo]2.0.co;2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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18
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Oliveira-Carvalho AL, Guimarães PR, Abreu PA, Dutra DL, Junqueira-de-Azevedo IL, Rodrigues CR, Ho PL, Castro HC, Zingali RB. Identification and characterization of a new member of snake venom thrombin inhibitors from Bothrops insularis using a proteomic approach. Toxicon 2008; 51:659-71. [DOI: 10.1016/j.toxicon.2007.11.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 11/28/2007] [Accepted: 11/29/2007] [Indexed: 10/22/2022]
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Doley R, Tram NNB, Reza MA, Kini RM. Unusual accelerated rate of deletions and insertions in toxin genes in the venom glands of the pygmy copperhead (Austrelaps labialis) from Kangaroo island. BMC Evol Biol 2008; 8:70. [PMID: 18307759 PMCID: PMC2287176 DOI: 10.1186/1471-2148-8-70] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 02/28/2008] [Indexed: 11/20/2022] Open
Abstract
Background Toxin profiling helps in cataloguing the toxin present in the venom as well as in searching for novel toxins. The former helps in understanding potential pharmacological profile of the venom and evolution of toxins, while the latter contributes to understanding of novel mechanisms of toxicity and provide new research tools or prototypes of therapeutic agents. Results The pygmy copperhead (Austrelaps labialis) is one of the less studied species. In this present study, an attempt has been made to describe the toxin profile of A. labialis from Kangaroo Island using the cDNA library of its venom glands. We sequenced 658 clones which represent the common families of toxin genes present in snake venom. They include (a) putative long-chain and short-chain neurotoxins, (b) phospholipase A2, (c) Kunitz-type protease inhibitor, (d) CRISPs, (e) C-type lectins and (f) Metalloproteases. In addition, we have also identified a novel protein with two Kunitz-type domains in tandem similar to bikunin. Conclusion Interestingly, the cDNA library reveals that most of the toxin families (17 out of 43 toxin genes; ~40%) have truncated transcripts due to insertion or deletion of nucleotides. These truncated products might not be functionally active proteins. However, cellular trancripts from the same venom glands are not affected. This unusual higher rate of deletion and insertion of nucleotide in toxin genes may be responsible for the lower toxicity of A. labialis venom of Kangroo Island and have significant effect on evolution of toxin genes.
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Affiliation(s)
- Robin Doley
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore.
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Zelanis A, de Souza Ventura J, Chudzinski-Tavassi AM, de Fátima Domingues Furtado M. Variability in expression of Bothrops insularis snake venom proteases: an ontogenetic approach. Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:601-9. [PMID: 17398162 DOI: 10.1016/j.cbpc.2007.02.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 02/12/2007] [Accepted: 02/13/2007] [Indexed: 11/21/2022]
Abstract
Bothrops insularis is a threatened snake endemic to Queimada Grande Island, southern coast of São Paulo, Brazil, and the occurrence of sexual abnormalities in males, females and intersexes (females with functional ovaries and rudimentary hemipenis) has been reported in this population. The aim of this study was to identify ontogenetic shifts in protease expression of offspring of captive-bred B. insularis. Three neonates from a single litter were maintained at the facilities of Laboratory of Herpetology, Institute Butantan, for 41 months. The snakes were individually milked and venoms were analyzed both by SDS-PAGE, under reducing conditions, and for biochemical activities. The venoms from the mother and from a pool of adult specimens were used as references. In regard to the electrophoretic patterns, common bands were identified mainly between 14 and 50 kDa among snakes. The occurrence of proteolytic activity was noticed predominantly between 27 and 45 kDa in zymograms. Inhibitory assays with 1,10-phenantroline (10 mM) and PMSF (5 mM) showed that venoms possessed both metalloproteases and serine proteases. Venoms of young specimens showed a higher coagulant activity than those of adults, especially upon factors X and II. All venoms presented fibrino(geno)lytic activity, degrading Aalpha and Bbeta chains of fibrinogen, and lysing fibrin plate. These findings can reflect important individual, ontogenetic and sexual differences on venom composition and are likely correlated with diet habits of this species.
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Affiliation(s)
- André Zelanis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Brazil; Laboratório de Herpetologia, Instituto Butantan, Av. Vital Brazil, 1500, 05503-900, São Paulo-SP, Brazil
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21
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Hamako J, Suzuki Y, Hayashi N, Kimura M, Ozeki Y, Hashimoto K, Matsui T. Amino acid sequence and characterization of C-type lectin purified from the snake venom of Crotalus ruber. Comp Biochem Physiol B Biochem Mol Biol 2007; 146:299-306. [PMID: 17251046 DOI: 10.1016/j.cbpb.2006.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 10/12/2006] [Accepted: 11/09/2006] [Indexed: 11/24/2022]
Abstract
Galactoside-binding lectin was purified from the snake venom of Crotalus ruber by affinity chromatography on a lactose-agarose column, and the complete amino acid sequence was determined. The C. ruber venom lectin (CRL) showed a single band of 28 kDa by SDS-polyacrylamide electrophoresis under non-reducing conditions, but it showed a single band of 15 kDa under reducing conditions, indicating that CRL is a disulfide-linked homodimer of 15 kDa subunit. CRL specifically recognized beta-galactosides such as thiodigalactoside followed by N-acetylgalactosamine when examined with their inhibitory effects on CRL-induced hemagglutination. A CRL subunit was composed of 135 residues containing nine Cys residues and showed a high similarity to other C-type galactoside-binding lectins from snake venoms. C. atrox lectin (CAL) showed almost the same sequence except for eight amino acid residues. Neither CRL nor CAL induced platelet aggregation by itself or inhibited platelet aggregation mediated by von Willebrand factor or fibrinogen with agonists. CRL showed a similar oligomeric form and the sugar specificity as CAL, but it showed different divalent cation sensitivity such as Mn(2+) and Ni(2+). Homology modeling suggested that the amino acid substitution found in CRL does not affect sugar recognition of the lectin but might alter the conformation and influence the sugar binding pocket induced by the metal-ion binding.
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Affiliation(s)
- Jiharu Hamako
- Course of Medical Communication, Fujita Health University College Toyoake, Aichi 470-1192, Japan
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22
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Cogo JC, Lilla S, Souza GHMF, Hyslop S, de Nucci G. Purification, sequencing and structural analysis of two acidic phospholipases A2 from the venom of Bothrops insularis (jararaca ilhoa). Biochimie 2006; 88:1947-59. [PMID: 17140721 DOI: 10.1016/j.biochi.2006.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2005] [Accepted: 10/05/2006] [Indexed: 12/21/2022]
Abstract
Bothrops snake venoms contain a variety of phospholipases (PLA(2)), some of which are myotoxic. In this work, we used reverse-phase HPLC and mass spectrometry to purify and sequence two PLA(2) from the venom of Bothrops insularis. The two enzymes, designated here as BinTX-I and BinTx-II, were acidic (pI 5.05 and 4.49) Asp49 PLA(2), with molecular masses of 13,975 and 13,788, respectively. The amino acid sequence and molecular mass of BinTX-I were identical to those of a PLA(2) previously isolated from this venom (PA2_BOTIN, SwissProt accession number ) while those of BinTX-II indicated that this was a new enzyme. Multiple sequence alignments with other Bothrops PLA(2) showed that the amino acids His48, Asp49, Tyr52 and Asp99, which are important for enzymatic activity, were fully conserved, as were the 14 cysteine residues involved in disulfide bond formation, in addition to various other residues. A phylogenetic analysis showed that BinTX-I and BinTX-II grouped with other acidic Asp49 PLA(2) from Bothrops venoms, and computer modeling indicated that these enzymes had the characteristic structure of bothropic PLA(2) that consisted of three alpha-helices, a beta-wing, a short helix and a calcium-binding loop. BinTX-I (30 microg/paw) produced mouse hind paw edema that was maximal after 1h compared to after 3h with venom (10 and 100 microg/paw); in both cases, the edema decreased after 6h. BinTX-1 and venom (40 microg/ml each) produced time-dependent neuromuscular blockade in chick biventer cervicis preparations that reached 40% and 95%, respectively, after 120 min. BinTX-I also produced muscle fiber damage and an elevation in CK, as also seen with venom. These results indicate that BinTX-I contributes to the neuromuscular activity and tissue damage caused by B. insularis venom in vitro and in vivo.
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Affiliation(s)
- José C Cogo
- Laboratório de Fisiologia e Farmacodinâmica, Instituto de Pesquisa e Desenvolvimento, e Serpentário do Centro de Estudos da Natureza (CEN), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, Urbanova, São José dos Campos, SP, Brazil
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23
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Abreu PA, Albuquerque MG, Rodrigues CR, Castro HC. Structure–function inferences based on molecular modeling, sequence-based methods and biological data analysis of snake venom lectins. Toxicon 2006; 48:690-701. [PMID: 17046438 DOI: 10.1016/j.toxicon.2006.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2006] [Revised: 08/05/2006] [Accepted: 08/07/2006] [Indexed: 10/24/2022]
Abstract
Lectins are a structurally and functionally diverse group of proteins from different sources, capable to recognize and bind specifically carbohydrates. Several snake venoms contain calcium-dependent true lectins (SVLs) that recognize galactose. Herein, in order to enlighten some of the structure-function relationships of snake venom lectins (SVLs), we constructed theoretical models for 10 SVLs based on the Crotalus atrox lectin (CaL), the only SVL crystal structure available, and compared with other animal and plant lectins, and C-type lectin-like proteins (CLPs) that do not bind carbohydrates. Although these are theoretical structures, we could identify some SVL features, including: (i) a singular intrachain disulfide bond (Cys(38)-Cys(133)) that is not present in CLPs; (ii) a significant reorientation (39-41A) of the 80's loop position that folds back to the globular domain, assists the carbohydrate recognition domain (CRD), and orients the dimer formation, even in BfL-1 and BfL-2, which did not present the Cys(86) interchain; (iii) a CRD presenting a negative and concave surface that allows the interaction with the specific saccharide hydroxyl groups and calcium ion; (iv) the role of water molecules in some interchain interactions, similar to other animal and plant lectins; and (v) the inability of forming oligomers in contrast to CaL and some CLPs, such as convulxin.
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Affiliation(s)
- Paula Alvarez Abreu
- Laboratório de Bioquímica e Modelagem Molecular, Departamento de Biologia Celular e Molecular, Instituto de Biologia, CEG, Universidade Federal Fluminense, CEP 24001-970, Niterói, RJ, Brazil
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Cidade DAP, Simão TA, Dávila AMR, Wagner G, Junqueira-de-Azevedo IDLM, Ho PL, Bon C, Zingali RB, Albano RM. Bothrops jararaca venom gland transcriptome: analysis of the gene expression pattern. Toxicon 2006; 48:437-61. [PMID: 16905169 DOI: 10.1016/j.toxicon.2006.07.008] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Bothrops jararaca is a pit viper responsible for the majority of snake envenoming accidents in Brazil. As an attempt to describe the transcriptional activity of the venom gland, ESTs of a cDNA library constructed from B. jararaca venom gland were generated and submitted to bioinformatics analysis. The results showed a clear predominance of transcripts coding for toxins instead of transcripts coding for proteins involved in cellular functions. Among toxins, the most frequent transcripts were from metalloproteinases (52.6%), followed by serine-proteinases (28.5%), C-type lectins (8.3%) and bradykinin-potentiating peptides (BPPs) (6.2%). Results were similar to that obtained from the transcriptome analysis of B. insularis, a phylogenetically close sister of B. jararaca, though some differences were observed and are pointed out, such as a higher amount of the hypotensive BPPs in B. insularis transcriptome (19.7%). Another striking difference observed is that PIII and PII-classes of metalloproteinases are similarly represented in B. jararaca in contrast to B. insularis, in which a predominance of PIII-class metalloproteinase, which present a more intense hemorrhagic action, is observed. These features may, in part, explain the higher potency of B. insularis venom. The results obtained can help in proteome studies, and the clones can be used to directly probe the genetic material from other snake species or to investigate differences in gene expression pattern in response to factors such as diet, aging and geographic localization.
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Affiliation(s)
- Daniela A P Cidade
- Departamento de Bioquímica, Universidade do Estado do Rio de Janeiro, CEP 20551 013 Rio de Janeiro, RJ, Brasil.
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25
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Panunto PC, da Silva MA, Linardi A, Buzin MP, Melo SESFC, Mello SM, Prado-Franceschi J, Hyslop S. Biological activities of a lectin from Bothrops jararacussu snake venom. Toxicon 2006; 47:21-31. [PMID: 16309723 DOI: 10.1016/j.toxicon.2005.08.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Accepted: 08/19/2005] [Indexed: 11/27/2022]
Abstract
Snake venoms contain saccharide-binding lectins. In this work, we examined the biological activities of a lectin (BjcuL) purified from Bothrops jararacussu snake venom by chromatography on non-derivatized Sepharose 4B and Sephacryl S-200 HR. The protein, a homodimer with subunits of 14.5 kDa, gave a single immunoprecipitin line in immunoelectrophoresis and cross-reacted in ELISA with antivenoms raised against Bothrops spp. (lanceheads), Micrurus spp. (coral snakes), Crotalus durissus terrificus (South American rattlesnake), and arthropod (Loxosceles gaucho, Phoneutria nigriventer and Tityus serrulatus) venoms. BjcuL agglutinated human formaldehyde-fixed erythrocytes at > or = 100 ng/ml and was inhibited by lactose and EDTA (> or = 2 mM) and high concentrations (> 100 mM) of glucose and sucrose, but not by N-acetylglucosamine. BjcuL had no direct hemolytic activity and was devoid of esterase, PLA2 and proteolytic activities. The lectin (up to 200 microg/ml) did not aggregate human platelet-rich plasma (PRP) or washed platelets (WP), nor did it alter the aggregation induced by ADP in PRP or by thrombin in WP. When injected into mouse hind paws, BjcuL (10-100 microg/paw) caused edema and increased vascular permeability, with a maximum effect after 1h that persisted for up to 6 h (edema) or gradually decreased after the peak interval (vascular permeability). No hemorrhage was observed in BjcuL-injected paws. In anesthetized rats, B. jararacussu venom (200 microg/kg, i.v.) produced sustained hypotension (maximum decrease of approximately 60%) whereas a similar dose of BjcuL decreased the blood pressure by approximately 15%, with a rapid return to the resting level.
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Affiliation(s)
- Patrícia C Panunto
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), CP 6111, 13083-970 Campinas, SP, Brazil
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