1
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de Oliveira ALN, Lacerda MT, Ramos MJ, Fernandes PA. Viper Venom Phospholipase A2 Database: The Structural and Functional Anatomy of a Primary Toxin in Envenomation. Toxins (Basel) 2024; 16:71. [PMID: 38393149 PMCID: PMC10893444 DOI: 10.3390/toxins16020071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/04/2024] [Accepted: 01/13/2024] [Indexed: 02/25/2024] Open
Abstract
Viper venom phospholipase A2 enzymes (vvPLA2s) and phospholipase A2-like (PLA2-like) proteins are two of the principal toxins in viper venom that are responsible for the severe myotoxic and neurotoxic effects caused by snakebite envenoming, among other pathologies. As snakebite envenoming is the deadliest neglected tropical disease, a complete understanding of these proteins' properties and their mechanisms of action is urgently needed. Therefore, we created a database comprising information on the holo-form, cofactor-bound 3D structure of 217 vvPLA2 and PLA2-like proteins in their physiologic environment, as well as 79 membrane-bound viper species from 24 genera, which we have made available to the scientific community to accelerate the development of new anti-snakebite drugs. In addition, the analysis of the sequenced, 3D structure of the database proteins reveals essential aspects of the anatomy of the proteins, their toxicity mechanisms, and the conserved binding site areas that may anchor universal interspecific inhibitors. Moreover, it pinpoints hypotheses for the molecular origin of the myotoxicity of the PLA2-like proteins. Altogether, this study provides an understanding of the diversity of these toxins and how they are conserved, and it indicates how to develop broad, interspecies, efficient small-molecule inhibitors to target the toxin's many mechanisms of action.
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Affiliation(s)
| | | | | | - Pedro A. Fernandes
- Requimte-Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-000 Porto, Portugal; (A.L.N.d.O.); (M.T.L.); (M.J.R.)
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2
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Structural and functional studies of a snake venom phospholipase A 2-like protein complexed to an inhibitor from Tabernaemontana catharinensis. Biochimie 2023; 206:105-115. [PMID: 36273763 DOI: 10.1016/j.biochi.2022.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/19/2022] [Accepted: 10/17/2022] [Indexed: 11/22/2022]
Abstract
Snake envenomation is an ongoing global health problem and tropical neglected disease that afflicts millions of people each year. The only specific treatment, antivenom, has several limitations that affects its proper distribution to the victims and its efficacy against local effects, such as myonecrosis. The main responsible for this consequence are the phospholipases A2 (PLA2) and PLA2-like proteins, such as BthTX-I from Bothrops jararacussu. Folk medicine resorts to plants such as Tabernaemontana catharinensis to palliate these and other snakebite effects. Here, we evaluated the effect of its root bark extract and one of its isolated compounds, 12-methoxy-4-methyl-voachalotine (MMV), against the in vitro paralysis and muscle damage induced by BthTX-I. Secondary and quaternary structures of BthTX-I were not modified by the interaction with MMV. Instead, this compound interacted in an unprecedented way with the region inside the toxin hydrophobic channel and promoted a structural change in Val31, loop 58-71 and Membrane Disruption Site. Thus, we hypothesize that MMV inhibits PLA2-like proteins by preventing entrance of fatty acid into the hydrophobic channel. These data may explain the traditional use of T. catharinensis extract and confirm MMV as a promising candidate to complement antivenom or a structural guide to develop more effective inhibitors.
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3
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Muniz EG, Sano-Martins IS, Saraiva MDGG, Monteiro WM, Magno ES, Oliveira SS. Biological characterization of the Bothrops brazili snake venom and its neutralization by Brazilian Bothrops antivenom produced by the Butantan Institute. Toxicon 2023; 223:107010. [PMID: 36586491 DOI: 10.1016/j.toxicon.2022.107010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022]
Abstract
We evaluated the ability of the Bothrops antivenom produced by the Butantan Institute to neutralize the lethal, hemorrhagic, myotoxic and phospholipase A2 activities induced by B. brazili venom from Rondônia state, Brazil, and verified its cross-reactivity against this venom. This antivenom neutralized the cited biological activities. It also showed cross-reactivity with this venom, and preferentially recognized components with a relative mass above 66 kDa. Our results suggest that Brazilian Bothrops antivenom can be used in B. brazili envenomation in this region.
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Affiliation(s)
- Emiro G Muniz
- Department of Epidemiology and Public Health, Dr Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, 69040-000, Brazil
| | - Ida S Sano-Martins
- Pathophysiology Laboratory, Butantan Institute, São Paulo, 05503-900, Brazil
| | - Maria das Graças G Saraiva
- Department of Epidemiology and Public Health, Dr Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, 69040-000, Brazil; Research Department, Dr Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, 69040-000, Brazil
| | - Wuelton Marcelo Monteiro
- Teaching and Research Directorate, Dr Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, 69040-000, Brazil
| | - Evela S Magno
- Department of Epidemiology and Public Health, Dr Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, 69040-000, Brazil
| | - Sâmella S Oliveira
- Research Management, Hospital Foundation of Hematology and Hemotherapy of Amazonas, Manaus, 69050-001, Brazil; Teaching and Research Center, Francisca Mendes Heart Hospital Foundation, Manaus, 69097-720, Brazil.
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4
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Yang D, Liu X, Li J, Xie J, Jiang L. Animal venoms: a novel source of anti- Toxoplasma gondii drug candidates. Front Pharmacol 2023; 14:1178070. [PMID: 37205912 PMCID: PMC10188992 DOI: 10.3389/fphar.2023.1178070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is a nucleated intracellular parasitic protozoan with a broad host selectivity. It causes toxoplasmosis in immunocompromised or immunodeficient patients. The currently available treatments for toxoplasmosis have significant side effects as well as certain limitations, and the development of vaccines remains to be explored. Animal venoms are considered to be an important source of novel antimicrobial agents. Some peptides from animal venoms have amphipathic alpha-helix structures. They inhibit the growth of pathogens by targeting membranes to produce lethal pores and cause membrane rupture. Venom molecules generally possess immunomodulatory properties and play key roles in the suppression of pathogenic organisms. Here, we summarized literatures of the last 15 years on the interaction of animal venom peptides with T. gondii and attempt to explore the mechanisms of their interaction with parasites that involve membrane and organelle damage, immune response regulation and ion homeostasis. Finally, we analyzed some limitations of venom peptides for drug therapy and some insights into their development in future studies. It is hoped that more research will be stimulated to turn attention to the medical value of animal venoms in toxoplasmosis.
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Affiliation(s)
- Dongqian Yang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Xiaohua Liu
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Jing Li
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Jing Xie
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Liping Jiang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- China-Africa Research Center of Infectious Diseases, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- *Correspondence: Liping Jiang,
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5
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Soares BS, Rocha SLG, Bastos VA, Lima DB, Carvalho PC, Gozzo FC, Demeler B, Williams TL, Arnold J, Henrickson A, Jørgensen TJD, Souza TACB, Perales J, Valente RH, Lomonte B, Gomes-Neto F, Neves-Ferreira AGC. Molecular Architecture of the Antiophidic Protein DM64 and its Binding Specificity to Myotoxin II From Bothrops asper Venom. Front Mol Biosci 2022; 8:787368. [PMID: 35155563 PMCID: PMC8830425 DOI: 10.3389/fmolb.2021.787368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/07/2021] [Indexed: 01/11/2023] Open
Abstract
DM64 is a toxin-neutralizing serum glycoprotein isolated from Didelphis aurita, an ophiophagous marsupial naturally resistant to snake envenomation. This 64 kDa antitoxin targets myotoxic phospholipases A2, which account for most local tissue damage of viperid snakebites. We investigated the noncovalent complex formed between native DM64 and myotoxin II, a myotoxic phospholipase-like protein from Bothrops asper venom. Analytical ultracentrifugation (AUC) and size exclusion chromatography indicated that DM64 is monomeric in solution and binds equimolar amounts of the toxin. Attempts to crystallize native DM64 for X-ray diffraction were unsuccessful. Obtaining recombinant protein to pursue structural studies was also challenging. Classical molecular modeling techniques were impaired by the lack of templates with more than 25% sequence identity with DM64. An integrative structural biology approach was then applied to generate a three-dimensional model of the inhibitor bound to myotoxin II. I-TASSER individually modeled the five immunoglobulin-like domains of DM64. Distance constraints generated by cross-linking mass spectrometry of the complex guided the docking of DM64 domains to the crystal structure of myotoxin II, using Rosetta. AUC, small-angle X-ray scattering (SAXS), molecular modeling, and molecular dynamics simulations indicated that the DM64-myotoxin II complex is structured, shows flexibility, and has an anisotropic shape. Inter-protein cross-links and limited hydrolysis analyses shed light on the inhibitor's regions involved with toxin interaction, revealing the critical participation of the first, third, and fifth domains of DM64. Our data showed that the fifth domain of DM64 binds to myotoxin II amino-terminal and beta-wing regions. The third domain of the inhibitor acts in a complementary way to the fifth domain. Their binding to these toxin regions presumably precludes dimerization, thus interfering with toxicity, which is related to the quaternary structure of the toxin. The first domain of DM64 interacts with the functional site of the toxin putatively associated with membrane anchorage. We propose that both mechanisms concur to inhibit myotoxin II toxicity by DM64 binding. The present topological characterization of this toxin-antitoxin complex constitutes an essential step toward the rational design of novel peptide-based antivenom therapies targeting snake venom myotoxins.
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Affiliation(s)
- Barbara S. Soares
- Laboratory of Toxinology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil
| | | | - Viviane A. Bastos
- Laboratory of Toxinology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil
| | - Diogo B. Lima
- Department of Chemical Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Paulo C. Carvalho
- Laboratory for Structural and Computational Proteomics, Carlos Chagas Institute, Curitiba, Brazil
| | - Fabio C. Gozzo
- Dalton Mass Spectrometry Laboratory, University of Campinas, Campinas, Brazil
| | - Borries Demeler
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, Canada
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, United States
| | - Tayler L. Williams
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Janelle Arnold
- Department of Environmental Science, Princeton University, Princeton, NJ, United States
| | - Amy Henrickson
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, Canada
| | - Thomas J. D. Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Tatiana A. C. B. Souza
- Laboratory for Structural and Computational Proteomics, Carlos Chagas Institute, Curitiba, Brazil
| | - Jonas Perales
- Laboratory of Toxinology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil
| | - Richard H. Valente
- Laboratory of Toxinology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil
| | - Bruno Lomonte
- Clodomiro Picado Institute, University of Costa Rica, San José, Costa Rica
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6
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Barbosa ED, Lima Neto JX, Bezerra KS, Oliveira JIN, Machado LD, Fulco UL. Quantum Biochemical Investigation of Lys49-PLA 2 from Bothrops moojeni. J Phys Chem B 2021; 125:12972-12980. [PMID: 34793159 DOI: 10.1021/acs.jpcb.1c07298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Envenomation via snakebites occurs largely in areas where it is harder to access the hospital. Its mortality rate and sequelae acquired by the survivors symbolize a big challenge for antivenom therapy. In particular, the homologous phospholipase A2 (Lys49-PLA2) proteins can induce myonecrosis and are not effectively neutralized by current treatments. Thus, by taking advantage of crystallographic structures of Bothrops moojeni Lys49-PLA2 complexed with VRD (varespladib) and AIN (aspirin), a quantum biochemistry study based on the molecular fractionation with conjugate cap scheme within the density functional theory formalism is performed to unveil these complexes' detailed interaction energies. The calculations revealed that important interactions between ligands and the Lys49-PLA2 pocket could occur up to a pocket radius of r = 6.5 (5.0 Å) for VRD (AIN), with the total interaction energy of the VRD ligand being higher than that of the AIN ligand, which is well-correlated with the experimental binding affinity. Furthermore, we have identified the role played by the amino acids LYS0069, LYS0049, LEU0005, ILE0009, CYS0029, GLY0030, HIS0048, PRO0018, ALA0019, CYS0045, TYR0052, TYR0022, PRO0125*, and PHE0126* (LYS0069, LYS0049, GLY0032, LEU0002, and LEU0005) in the VRD↔Lys49-PLA2 (AIN↔Lys49-PLA2) complex. Our simulations are a valuable tool to support the big challenge for neutralizing the damages in victims of snakebites.
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Affiliation(s)
- E D Barbosa
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
| | - J X Lima Neto
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
| | - K S Bezerra
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
| | - J I N Oliveira
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
| | - L D Machado
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
| | - U L Fulco
- Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
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7
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Salvador GHM, Borges RJ, Lomonte B, Lewin MR, Fontes MRM. The synthetic varespladib molecule is a multi-functional inhibitor for PLA 2 and PLA 2-like ophidic toxins. Biochim Biophys Acta Gen Subj 2021; 1865:129913. [PMID: 33865953 DOI: 10.1016/j.bbagen.2021.129913] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND The treatment for snakebites is early administration of antivenom, which can be highly effective in inhibiting the systemic effects of snake venoms, but is less effective in the treatment of extra-circulatory and local effects. To complement standard-of-care treatments such as antibody-based antivenoms, natural and synthetic small molecules have been proposed for the inhibition of key venom components such as phospholipase A2 (PLA2) and PLA2-like toxins. Varespladib (compound LY315920) is a synthetic molecule developed and clinically tested aiming to block inflammatory cascades of several diseases associated with high PLA2s. Recent studies have demonstrated this molecule is able to potently inhibit snake venom catalytic PLA2 and PLA2-like toxins. METHODS In vivo and in vitro techniques were used to evaluate the inhibitory effect of varespladib against MjTX-I. X-ray crystallography was used to reveal details of the interaction between these molecules. A new methodology that combines crystallography, mass spectroscopy and phylogenetic data was used to review its primary sequence. RESULTS Varespladib was able to inhibit the myotoxic and cytotoxic effects of MjTX-I. Structural analysis revealed a particular inhibitory mechanism of MjTX-I when compared to other PLA2-like myotoxin, presenting an oligomeric-independent function. CONCLUSION Results suggest the effectiveness of varespladib for the inhibition of MjTX-I, in similarity with other PLA2 and PLA2-like toxins. GENERAL SIGNIFICANCE Varespladib appears to be a promissory molecule in the treatment of local effects led by PLA2 and PLA2-like toxins (oligomeric dependent and independent), indicating that this is a multifunctional or broadly specific inhibitor for different toxins within this superfamily.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Rafael J Borges
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
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8
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In-solution structural studies involving a phospholipase A 2-like myotoxin and a natural inhibitor: Plasticity of oligomeric assembly affects mechanisms of inhibition. Biochimie 2020; 181:145-153. [PMID: 33333169 DOI: 10.1016/j.biochi.2020.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 02/02/2023]
Abstract
Snakebite envenomation has been categorized by World Health Organization as a category A neglected tropical disease, since it causes chronic psychological disorders, physical disablement and death. Ophidian accidents may cause local myonecrosis that cause drastic sequelae, which are not efficiently neutralized via serum therapy. Phospholipase A2-like (PLA2-like) myotoxins have a major role in the local effects caused by several snake venoms. We previously demonstrated that chicoric acid (CA) is an efficient inhibitor of the BthTX-I myotoxin and solved the X-ray structure of complex. Herein, we assess the oligomeric behavior of the BthTX-I/CA complex in solution under different physical-chemical conditions and using toxin obtained by two different biochemical methodologies to fully elucidate structural bases of inhibition of myotoxins by CA. We demonstrated the ability of PLA2-like proteins to form different oligomeric assemblies in the presence of certain inhibitors, which can also be modulated by buffer polarity change. In the presence of ethanol, BthTX-I/CA remains predominantly in a monomeric conformation, which prevents it from being in its active form (dimeric conformation). In contrast, in the absence of ethanol, the tetramer assembly was observed, which hid key regions of the protein responsible for docking and disruption of the muscle membrane. Therefore, the "plasticity" of these proteins with regard to their abilities to form oligomeric assemblies is a key issue for the future development of therapeutic agents to complement of serum therapy.
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9
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The allosteric activation mechanism of a phospholipase A 2-like toxin from Bothrops jararacussu venom: a dynamic description. Sci Rep 2020; 10:16252. [PMID: 33004851 PMCID: PMC7529814 DOI: 10.1038/s41598-020-73134-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/24/2020] [Indexed: 11/08/2022] Open
Abstract
The activation process of phospholipase A2-like (PLA2-like) toxins is a key step in their molecular mechanism, which involves oligomeric changes leading to the exposure of specific sites. Few studies have focused on the characterization of allosteric activators and the features that distinguish them from inhibitors. Herein, a comprehensive study with the BthTX-I toxin from Bothrops jararacussu venom bound or unbound to α-tocopherol (αT) was carried out. The oligomerization state of BthTX-I bound or unbound to αT in solution was studied and indicated that the toxin is predominantly monomeric but tends to oligomerize when complexed with αT. In silico molecular simulations showed the toxin presents higher conformational changes in the absence of αT,
which suggests that it is important to stabilize the structure of the toxin. The transition between the two states (active/inactive) was also studied, showing that only the unbound BthTX-I system could migrate to the inactive state. In contrast, the presence of αT induces the toxin to leave the inactive state, guiding it towards the active state, with more regions exposed to the solvent, particularly its active site. Finally, the structural determinants necessary for a molecule to be an inhibitor or activator were analyzed in light of the obtained results.
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10
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Sanz L, Pérez A, Quesada-Bernat S, Diniz-Sousa R, Calderón LA, Soares AM, Calvete JJ, Caldeira CAS. Venomics and antivenomics of the poorly studied Brazil's lancehead, Bothrops brazili (Hoge, 1954), from the Brazilian State of Pará. J Venom Anim Toxins Incl Trop Dis 2020; 26:e20190103. [PMID: 32362928 PMCID: PMC7179968 DOI: 10.1590/1678-9199-jvatitd-2019-0103] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/28/2020] [Indexed: 11/26/2022] Open
Abstract
Background: The Brazil’s lancehead, Bothrops brazili, is a poorly
studied pit viper distributed in lowlands of the equatorial rainforests of
southern Colombia, northeastern Peru, eastern Ecuador, southern and
southeastern Venezuela, Guyana, Suriname, French Guiana, Brazil, and
northern Bolivia. Few studies have been reported on toxins isolated from
venom of Ecuadorian and Brazilian B. brazili. The aim of
the present study was to elucidate the qualitative and quantitative protein
composition of B. brazili venom from Pará (Brazil), and to
carry out a comparative antivenomics assessment of the immunoreactivity of
the Brazilian antibothropic pentavalent antivenom [soro
antibotrópico (SAB) in Portuguese] against the venoms of
B. brazili and reference species, B.
jararaca. Methods: We have applied a quantitative snake venomics approach, including
reverse-phase and two-dimensional electrophoretic decomplexation of the
venom toxin arsenal, LC-ESI-MS mass profiling and peptide-centric MS/MS
proteomic analysis, to unveil the overall protein composition of B.
brazili venom from Pará (Brazil). Using third-generation
antivenomics, the specific and paraspecific immunoreactivity of the
Brazilian SAB against homologous (B. jararaca) and
heterologous (B. brazili) venoms was investigated. Results: The venom proteome of the Brazil’s lancehead (Pará) is predominantly composed
of two major and three minor acidic (19%) and two major and five minor basic
(14%) phospholipase A2 molecules; 7-11 snake venom
metalloproteinases of classes PI (21%) and PIII (6%); 10-12 serine
proteinases (14%), and 1-2 L-amino acid oxidases (6%). Other toxins,
including two cysteine-rich secretory proteins, one C-type lectin-like
molecule, one nerve growth factor, one 5'-nucleotidase, one
phosphodiesterase, one phospholipase B, and one glutaminyl cyclase molecule,
represent together less than 2.7% of the venom proteome. Third generation
antivenomics profile of the Brazilian pentabothropic antivenom showed
paraspecific immunoreactivity against all the toxin classes of B.
brazili venom, with maximal binding capacity of
132.2 mg venom/g antivenom. This figure indicates that 19% of antivenom's
F(ab')2 antibodies bind B. brazili venom
toxins. Conclusion: The proteomics outcome contribute to a deeper insight into the spectrum of
toxins present in the venom of the Brazil’s lancehead, and rationalize the
pathophysiology underlying this snake bite envenomings. The comparative
qualitative and quantitative immunorecognition profile of the Brazilian
pentabothropic antivenom toward the venom toxins of B.
brazili and B. jararaca (the reference venom
for assessing the bothropic antivenom's potency in Brazil), provides clues
about the proper use of the Brazilian antibothropic polyvalent antivenom in
the treatment of bites by the Brazil’s lancehead.
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Affiliation(s)
- Libia Sanz
- Evolutionary and Translational Venomics Laboratory, Spanish National Research Council (CSIC), Valencia, Spain
| | - Alicia Pérez
- Evolutionary and Translational Venomics Laboratory, Spanish National Research Council (CSIC), Valencia, Spain
| | - Sarai Quesada-Bernat
- Evolutionary and Translational Venomics Laboratory, Spanish National Research Council (CSIC), Valencia, Spain
| | - Rafaela Diniz-Sousa
- Center for the Study of Biomolecules Applied to Health (CEBio), Oswaldo Cruz Foundation Rondônia, Porto Velho, RO, Brazil.,Graduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), Porto Velho, RO, Brazil.,São Lucas University Center (UniSL), Porto Velho, RO, Brazil
| | - Leonardo A Calderón
- Center for the Study of Biomolecules Applied to Health (CEBio), Oswaldo Cruz Foundation Rondônia, Porto Velho, RO, Brazil.,Graduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), Porto Velho, RO, Brazil.,Graduate Program in Biodiversity and Biotechnology, BIONORTE Network, Porto Velho, RO, Brazil.,Aparício Carvalho University Center (FIMCA), Porto Velho, RO, Brazil
| | - Andreimar M Soares
- Center for the Study of Biomolecules Applied to Health (CEBio), Oswaldo Cruz Foundation Rondônia, Porto Velho, RO, Brazil.,Graduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), Porto Velho, RO, Brazil.,São Lucas University Center (UniSL), Porto Velho, RO, Brazil.,Graduate Program in Biodiversity and Biotechnology, BIONORTE Network, Porto Velho, RO, Brazil.,National Institute of Science and Technology in Epidemiology of the Western Amazônia, (INCT-EpiAmO), Porto Velho, RO, Brazil
| | - Juan J Calvete
- Evolutionary and Translational Venomics Laboratory, Spanish National Research Council (CSIC), Valencia, Spain
| | - Cleópatra A S Caldeira
- Center for the Study of Biomolecules Applied to Health (CEBio), Oswaldo Cruz Foundation Rondônia, Porto Velho, RO, Brazil.,Graduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), Porto Velho, RO, Brazil.,Graduate Program in Biodiversity and Biotechnology, BIONORTE Network, Porto Velho, RO, Brazil
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11
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Cardoso FF, Gomes AAS, Dreyer TR, Cavalcante WLG, Dal Pai M, Gallacci M, Fontes MRM. Neutralization of a bothropic PLA 2-like protein by caftaric acid, a novel potent inhibitor of ophidian myotoxicity. Biochimie 2020; 170:163-172. [PMID: 31978419 DOI: 10.1016/j.biochi.2020.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/19/2020] [Indexed: 11/18/2022]
Abstract
Envenoming by snakebite is an important global health issue that has received little attention, leading the World Health Organization to naming it as neglected tropical disease. Several snakebites present serious local symptoms manifested on victims that may not be efficiently neutralized by serum therapy. Phospholipase A2-like (PLA2-like) toxins are present in Viperidae venoms and are responsible for local myotoxic activity. Herein, we investigated the association between BthTX-I toxin and caftaric acid (CFT), a molecule present in plants. CFT neutralized neuromuscular blocking and muscle-damaging activities promoted by BthTX-I. Calorimetric and light-scattering assays demonstrated that CFT inhibitor interacted with dimeric BthTX-I. Bioinformatics simulations indicated that CFT inhibitor binds to the toxin's hydrophobic channel (HCh). According to the current myotoxic mechanism, three different regions of PLA2-like toxins have specific tasks: protein allosteric activation (HCh), membrane dockage (MDoS), and membrane rupture (MDiS). We propose CFT inhibitor interferes with the allosteric activation, which is related to the conformation change leading to the exposure/alignment of MDoS/MDiS region. This is the first report of a PLA2-like toxin fully inhibited by a compound that interacts only with its HCh region. Thus, CFT is a novel candidate to complement serum therapy and improve the treatment of snakebite.
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Affiliation(s)
- Fábio F Cardoso
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Antoniel A S Gomes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Thiago R Dreyer
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Walter L G Cavalcante
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Maeli Dal Pai
- Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Márcia Gallacci
- Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Marcos R M Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
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12
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Structural basis for phospholipase A 2-like toxin inhibition by the synthetic compound Varespladib (LY315920). Sci Rep 2019; 9:17203. [PMID: 31748642 PMCID: PMC6868273 DOI: 10.1038/s41598-019-53755-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/05/2019] [Indexed: 01/23/2023] Open
Abstract
The World Health Organization recently listed snakebite envenoming as a Neglected Tropical Disease, proposing strategies to significantly reduce the global burden of this complex pathology by 2030. In this context, effective adjuvant treatments to complement conventional antivenom therapy based on inhibitory molecules for specific venom toxins have gained renewed interest. Varespladib (LY315920) is a synthetic molecule clinically tested to block inflammatory cascades of several diseases associated with elevated levels of secreted phospholipase A2 (sPLA2). Most recently, Varespladib was tested against several whole snake venoms and isolated PLA2 toxins, demonstrating potent inhibitory activity. Herein, we describe the first structural and functional study of the complex between Varespladib and a PLA2-like snake venom toxin (MjTX-II). In vitro and in vivo experiments showed this compound’s capacity to inhibit the cytotoxic and myotoxic effects of MjTX-II from the medically important South American snake, Bothrops moojeni. Crystallographic and bioinformatics analyses revealed interactions of Varespladib with two specific regions of the toxin, suggesting inhibition occurs by physical blockage of its allosteric activation, preventing the alignment of its functional sites and, consequently, impairing its ability to disrupt membranes. Furthermore, based on the analysis of several crystallographic structures, a distinction between toxin activators and inhibitors is proposed.
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13
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Huancahuire-Vega S, Hollanda LM, Gomes-Heleno M, Newball-Noriega EE, Marangoni S. ACP-TX-I and ACP-TX-II, Two Novel Phospholipases A 2 Isolated from Trans-Pecos Copperhead Agkistrodon contortrix pictigaster Venom: Biochemical and Functional Characterization. Toxins (Basel) 2019; 11:toxins11110661. [PMID: 31739403 PMCID: PMC6891687 DOI: 10.3390/toxins11110661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/30/2019] [Accepted: 11/06/2019] [Indexed: 01/18/2023] Open
Abstract
This work reports the purification and biochemical and functional characterization of ACP-TX-I and ACP-TX-II, two phospholipases A2 (PLA2) from Agkistrodon contortrix pictigaster venom. Both PLA2s were highly purified by a single chromatographic step on a C18 reverse phase HPLC column. Various peptide sequences from these two toxins showed similarity to those of other PLA2 toxins from viperid snake venoms. ACP-TX-I belongs to the catalytically inactive K49 PLA2 class, while ACP-TX-II is a D49 PLA2, and is enzymatically active. ACP-TX-I PLA2 is monomeric, which results in markedly diminished myotoxic and inflammatory activities when compared with dimeric K49 PLA2s, confirming the hypothesis that dimeric structure contributes heavily to the profound myotoxicity of the most active viperid K49 PLA2s. ACP-TX-II exhibits the main pharmacological actions reported for this protein family, including in vivo local myotoxicity, edema-forming activity, and in vitro cytotoxicity. ACP-TX-I PLA2 is cytotoxic to A549 lung carcinoma cells, indicating that cytotoxicity to these tumor cells does not require enzymatic activity.
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Affiliation(s)
- Salomón Huancahuire-Vega
- Departamento de Ciencias Básicas, Facultad de Ciencias de la Salud, Escuela de Medicina Humana, Universidad Peruana Unión (UPeU), Lima 15, Peru;
- Correspondence: ; Tel.: +51-9-9757-4011
| | - Luciana M. Hollanda
- Instituto de Tecnologia e Pesquisa, Universidade Tiradentes (UNIT), Aracaju 49032-490, SE, Brazil;
| | - Mauricio Gomes-Heleno
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-970, SP, Brazil; (M.G.-H.); (S.M.)
| | - Edda E. Newball-Noriega
- Departamento de Ciencias Básicas, Facultad de Ciencias de la Salud, Escuela de Medicina Humana, Universidad Peruana Unión (UPeU), Lima 15, Peru;
| | - Sergio Marangoni
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-970, SP, Brazil; (M.G.-H.); (S.M.)
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14
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Sobrinho J, Francisco A, Simões-Silva R, Kayano A, Ruiz Diaz JA, Garay AG, Arruda A, Ferreira A, Santos A, Luiz M, Teles C, Pereira S, Zanchi F, Calderon L, Zuliani J, Soares A. Antimyotoxic Activity of Synthetic Peptides Derived from Bothrops atrox Snake Gamma Phospholipase A2 Inhibitor Selected by Virtual Screening. Curr Top Med Chem 2019; 19:1952-1961. [DOI: 10.2174/1568026619666190725102812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/13/2019] [Accepted: 07/04/2019] [Indexed: 11/22/2022]
Abstract
Background:
Several studies have aimed to identify molecules that inhibit the toxic actions
of snake venom phospholipases A2 (PLA2s). Studies carried out with PLA2 inhibitors (PLIs) have been
shown to be efficient in this assignment.
Objective:
This work aimed to analyze the interaction of peptides derived from Bothrops atrox PLIγ
(atPLIγ) with a PLA2 and to evaluate the ability of these peptides to reduce phospholipase and myotoxic
activities.
Methods:
Peptides were subjected to molecular docking with a homologous Lys49 PLA2 from B. atrox
venom modeled by homology. Phospholipase activity neutralization assay was performed with BthTX-II
and different ratios of the peptides. A catalytically active and an inactive PLA2 were purified from the B.
atrox venom and used together in the in vitro myotoxic activity neutralization experiments with the peptides.
Results:
The peptides interacted with amino acids near the PLA2 hydrophobic channel and the loop that
would be bound to calcium in Asp49 PLA2. They were able to reduce phospholipase activity and peptides
DFCHNV and ATHEE reached the highest reduction levels, being these two peptides the best that
also interacted in the in silico experiments. The peptides reduced the myotubes cell damage with a highlight
for the DFCHNV peptide, which reduced by about 65%. It has been suggested that myotoxic activity
reduction is related to the sites occupied in the PLA2 structure, which could corroborate the results
observed in molecular docking.
Conclusion:
This study should contribute to the investigation of the potential of PLIs to inhibit the toxic
effects of PLA2s.
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Affiliation(s)
- J.C. Sobrinho
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - A.F. Francisco
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - R. Simões-Silva
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - A.M. Kayano
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - J.J. Alfonso Ruiz Diaz
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - A.F. Gomez Garay
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - A. Arruda
- Laboratório de Engenharia de Anticorpos, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - A.S. Ferreira
- Laboratório da Plataforma de Bioensaios de Malária e Leishmaniose, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - A.P.A. Santos
- Laboratório da Plataforma de Bioensaios de Malária e Leishmaniose, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - M.B. Luiz
- Laboratório de Engenharia de Anticorpos, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - C.B.G. Teles
- Laboratório da Plataforma de Bioensaios de Malária e Leishmaniose, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - S.S. Pereira
- Laboratório de Engenharia de Anticorpos, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | - F.B. Zanchi
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - L.A. Calderon
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - J.P. Zuliani
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
| | - A.M. Soares
- Centro de Estudos de Biomoléculas Aplicadas à Saúde, CEBio, Fundação Oswaldo Cruz, FIOCRUZ, Fiocruz Rondônia, Brazil
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15
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SDS-induced oligomerization of Lys49-phospholipase A 2 from snake venom. Sci Rep 2019; 9:2330. [PMID: 30787342 PMCID: PMC6382788 DOI: 10.1038/s41598-019-38861-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/08/2019] [Indexed: 11/21/2022] Open
Abstract
Phospholipase A2 (PLA2) is one of the representative toxic components of snake venom. PLA2s are categorized into several subgroups according to the amino acid at position 49, which comprises either Asp49, Lys49, Arg49 or Ser49. Previous studies suggested that the Lys49-PLA2 assembles into an extremely stable dimer. Although the behavior on Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing or non-reducing conditions suggested the presence of intermolecular disulfide bonds, these bonds were not observed in the crystal structure of Lys49-PLA2. The reason for this discrepancy between the crystal structure and SDS-PAGE of Lys49-PLA2 remains unknown. In this study, we analyzed a Lys49-PLA2 homologue from Protobothrops flavoviridis (PflLys49-PLA2 BPII), by biophysical analyses including X-ray crystallography, SDS-PAGE, native-mass spectrometry, and analytical ultracentrifugation. The results demonstrated that PflLys49-PLA2 BPII spontaneously oligomerized in the presence of SDS, which is one of the strongest protein denaturants.
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16
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Salvador GHM, Cardoso FF, Gomes AA, Cavalcante WLG, Gallacci M, Fontes MRM. Search for efficient inhibitors of myotoxic activity induced by ophidian phospholipase A 2-like proteins using functional, structural and bioinformatics approaches. Sci Rep 2019; 9:510. [PMID: 30679550 PMCID: PMC6346006 DOI: 10.1038/s41598-018-36839-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/29/2018] [Indexed: 02/01/2023] Open
Abstract
Ophidian accidents are considered an important neglected tropical disease by the World Health Organization. Particularly in Latin America, Bothrops snakes are responsible for the majority of the snakebite envenomings that are not efficiently treated by conventional serum therapy. Thus, the search for simple and efficient inhibitors to complement this therapy is a promising research area, and a combination of functional and structural assays have been used to test candidate ligands against specific ophidian venom compounds. Herein, we tested a commercial drug (acetylsalicylic acid, ASA) and a plant compound with antiophidian properties (rosmarinic acid, RA) using myographic, crystallographic and bioinformatics experiments with a phospholipase A2-like toxin, MjTX-II. MjTX-II/RA and MjTX-II/ASA crystal structures were solved at high resolution and revealed the presence of ligands bound to different regions of the toxin. However, in vitro myographic assays showed that only RA is able to prevent the myotoxic effects of MjTX-II. In agreement with functional results, molecular dynamics simulations showed that the RA molecule remains tightly bound to the toxin throughout the calculations, whereas ASA molecules tend to dissociate. This approach aids the design of effective inhibitors of PLA2-like toxins and, eventually, may complement serum therapy.
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Affiliation(s)
- Guilherme H M Salvador
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Fábio Florença Cardoso
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Antoniel A Gomes
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Walter L G Cavalcante
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
- Depto. de Farmacologia, UFMG - Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Márcia Gallacci
- Depto. de Farmacologia, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Marcos R M Fontes
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil.
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17
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Structural and functional characterization of suramin-bound MjTX-I from Bothrops moojeni suggests a particular myotoxic mechanism. Sci Rep 2018; 8:10317. [PMID: 29985425 PMCID: PMC6037679 DOI: 10.1038/s41598-018-28584-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/26/2018] [Indexed: 11/25/2022] Open
Abstract
Local myonecrosis is the main event resulting from snakebite envenomation by the Bothrops genus and, frequently, it is not efficiently neutralized by antivenom administration. Proteases, phospholipases A2 (PLA2) and PLA2-like toxins are found in venom related to muscle damage. Functional sites responsible for PLA2-like toxins activity have been proposed recently; they consist of a membrane docking-site and a membrane rupture-site. Herein, a combination of functional, biophysical and crystallographic techniques was used to characterize the interaction between suramin and MjTX-I (a PLA2-like toxin from Bothrops moojeni venom). Functional in vitro neuromuscular assays were performed to study the biological effects of the protein-ligand interaction, demonstrating that suramin neutralizes the myotoxic effect of MjTX-I. Calorimetric assays showed two different binding events: (i) inhibitor-protein interactions and (ii) toxin oligomerization processes. These hypotheses were also corroborated with dynamic light and small angle X-ray scattering assays. The crystal structure of the MjTX-I/suramin showed a totally different interaction mode compared to other PLA2-like/suramin complexes. Thus, we suggested a novel myotoxic mechanism for MjTX-I that may be inhibited by suramin. These results can further contribute to the search for inhibitors that will efficiently counteract local myonecrosis in order to be used as an adjuvant of conventional serum therapy.
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18
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Salvador GH, dos Santos JI, Borges RJ, Fontes MR. Structural evidence for a fatty acid-independent myotoxic mechanism for a phospholipase A2-like toxin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:473-481. [DOI: 10.1016/j.bbapap.2017.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 10/18/2022]
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19
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Secreted Phospholipases A₂ from Animal Venoms in Pain and Analgesia. Toxins (Basel) 2017; 9:toxins9120406. [PMID: 29311537 PMCID: PMC5744126 DOI: 10.3390/toxins9120406] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 12/20/2022] Open
Abstract
Animal venoms comprise a complex mixture of components that affect several biological systems. Based on the high selectivity for their molecular targets, these components are also a rich source of potential therapeutic agents. Among the main components of animal venoms are the secreted phospholipases A2 (sPLA2s). These PLA2 belong to distinct PLA2s groups. For example, snake venom sPLA2s from Elapidae and Viperidae families, the most important families when considering envenomation, belong, respectively, to the IA and IIA/IIB groups, whereas bee venom PLA2 belongs to group III of sPLA2s. It is well known that PLA2, due to its hydrolytic activity on phospholipids, takes part in many pathophysiological processes, including inflammation and pain. Therefore, secreted PLA2s obtained from animal venoms have been widely used as tools to (a) modulate inflammation and pain, uncovering molecular targets that are implicated in the control of inflammatory (including painful) and neurodegenerative diseases; (b) shed light on the pathophysiology of inflammation and pain observed in human envenomation by poisonous animals; and, (c) characterize molecular mechanisms involved in inflammatory diseases. The present review summarizes the knowledge on the nociceptive and antinociceptive actions of sPLA2s from animal venoms, particularly snake venoms.
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20
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Diniz-Sousa R, Caldeira CAS, Kayano AM, Paloschi MV, Pimenta DC, Simões-Silva R, Ferreira AS, Zanchi FB, Matos NB, Grabner FP, Calderon LA, Zuliani JP, Soares AM. Identification of the Molecular Determinants of the Antibacterial Activity of LmutTX, a Lys49 Phospholipase A2
Homologue Isolated from Lachesis muta muta
Snake Venom (Linnaeus, 1766). Basic Clin Pharmacol Toxicol 2017; 122:413-423. [DOI: 10.1111/bcpt.12921] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 10/10/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Rafaela Diniz-Sousa
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
| | - Cleópatra A. S. Caldeira
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Biodiversity and Biotechnology Posgraduate Program; Rede BIONORTE; Manaus Brazil
| | - Anderson M. Kayano
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
| | - Mauro V. Paloschi
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Laboratory of Cellular Immunology Applied to Heath; Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
| | - Daniel. C. Pimenta
- Biochemistry and Biophysics Laboratory; Butantan Institute; Sao Paulo SP Brazil
| | - Rodrigo Simões-Silva
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
| | - Amália S. Ferreira
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
| | - Fernando B. Zanchi
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Biodiversity and Biotechnology Posgraduate Program; Rede BIONORTE; Manaus Brazil
| | - Najla B. Matos
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Microbiology Laboratory; Research Center on Tropical Medicine of Rondonia (CEPEM); Porto Velho RO Brazil
- Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
| | | | - Leonardo A. Calderon
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Biodiversity and Biotechnology Posgraduate Program; Rede BIONORTE; Manaus Brazil
| | - Juliana P. Zuliani
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Biodiversity and Biotechnology Posgraduate Program; Rede BIONORTE; Manaus Brazil
- Laboratory of Cellular Immunology Applied to Heath; Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
| | - Andreimar M. Soares
- Center for the Study of Biomolecules Applied to Heath (CEBio); Oswaldo Cruz Foundation (FIOCRUZ), Fiocruz Rondonia; Porto Velho RO Brazil
- Medicine Department; Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Experimental Biology Posgraduate Program (PGBIOEXP); Federal University of Rondonia (UNIR); Porto Velho RO Brazil
- Biodiversity and Biotechnology Posgraduate Program; Rede BIONORTE; Manaus Brazil
- Sao Lucas Universitary Center (UNISL); Porto Velho RO Brazil
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21
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PLA 2-like proteins myotoxic mechanism: a dynamic model description. Sci Rep 2017; 7:15514. [PMID: 29138410 PMCID: PMC5686144 DOI: 10.1038/s41598-017-15614-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/19/2017] [Indexed: 11/23/2022] Open
Abstract
Phospholipase A2-like (PLA2-like) proteins contribute to the development of muscle necrosis in Viperidae snake bites and are not efficiently neutralized by current antivenom treatments. The toxic mechanisms of PLA2-like proteins are devoid of catalytic activity and not yet fully understood, although structural and functional experiments suggest a dimeric assembly and that the C-terminal residues are essential to myotoxicity. Herein, we characterized the functional mechanism of bothropic PLA2-like structures related to global and local measurements using the available models in the Protein Data Bank and normal mode molecular dynamics (NM-MD). Those measurements include: (i) new geometric descriptions between their monomers, based on Euler angles; (ii) characterizations of canonical and non-canonical conformations of the C-terminal residues; (iii) accessibility of the hydrophobic channel; (iv) inspection of ligands; and (v) distance of clustered residues to toxin interface of interaction. Thus, we described the allosteric activation of PLA2-like proteins and hypothesized that the natural movement between monomers, calculated from NM-MD, is related to their membrane disruption mechanism, which is important for future studies of the inhibition process. These methods and strategies can be applied to other proteins to help understand their mechanisms of action.
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Structural studies with BnSP-7 reveal an atypical oligomeric conformation compared to phospholipases A2-like toxins. Biochimie 2017; 142:11-21. [DOI: 10.1016/j.biochi.2017.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/21/2017] [Indexed: 12/21/2022]
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Functional and structural studies of a Phospholipase A2-like protein complexed to zinc ions: Insights on its myotoxicity and inhibition mechanism. Biochim Biophys Acta Gen Subj 2017; 1861:3199-3209. [DOI: 10.1016/j.bbagen.2016.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 12/28/2022]
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Crystal structure of a phospholipase A 2 from Bothrops asper venom: Insights into a new putative "myotoxic cluster". Biochimie 2016; 133:95-102. [PMID: 28034717 DOI: 10.1016/j.biochi.2016.12.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/20/2016] [Accepted: 12/23/2016] [Indexed: 11/20/2022]
Abstract
Snake venoms from the Viperidae and Elapidae families often have several phospholipases A2 (PLA2s), which may display different functions despite having a similar structural scaffold. These proteins are considered an important target for the development of drugs against local myotoxic damage because they are not efficiently neutralized by conventional serum therapy. PLA2s from these venoms are generally divided into two classes: (i) catalytic PLA2s (or Asp49-PLA2s) and (ii) non-catalytic PLA2-like toxins (or Lys49-PLA2s). In many Viperidae venoms, a subset of the basic Asp49-PLA2s displays some functional and structural characteristics of PLA2-like proteins and group within the same phylogenetic clade, but their myotoxic mechanism is still largely unknown. In the present study, we have crystallized and solved the structure of myotoxin I (MT-I), a basic myotoxic Asp49-PLA2 isolated from Bothrops asper venom. The structure presents a dimeric conformation that is compatible with that of previous dimers found for basic myotoxic Asp49-PLA2s and Lys49-PLA2s and has been confirmed by other biophysical and bioinformatics techniques. This arrangement suggests a possible cooperative action between both monomers to exert myotoxicity via two different sites forming a putative membrane-docking site (MDoS) and a putative membrane disruption site (MDiS). This mechanism would resemble that proposed for Lys49-PLA2s, but the sites involved appear to be situated in a different region. Thus, as both sites are close to one another, they form a "myotoxic cluster", which is also found in two other basic myotoxic Asp49-PLA2s from Viperidae venoms. Such arrangement may represent a novel structural strategy for the mechanism of muscle damage exerted by the group of basic, Asp49-PLA2s found in viperid snake venoms.
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Borges IP, Castanheira LE, Barbosa BF, de Souza DLN, da Silva RJ, Mineo JR, Tudini KAY, Rodrigues RS, Ferro EAV, de Melo Rodrigues V. Anti-parasitic effect on Toxoplasma gondii induced by BnSP-7, a Lys49-phospholipase A2 homologue from Bothrops pauloensis venom. Toxicon 2016; 119:84-91. [DOI: 10.1016/j.toxicon.2016.05.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/13/2016] [Accepted: 05/18/2016] [Indexed: 12/20/2022]
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Carregari VC, Dai J, Verano-Braga T, Rocha T, Ponce-Soto LA, Marangoni S, Roepstorff P. Revealing the functional structure of a new PLA2 K49 from Bothriopsis taeniata snake venom employing automatic “de novo” sequencing using CID/HCD/ETD MS/MS analyses. J Proteomics 2016; 131:131-139. [DOI: 10.1016/j.jprot.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 11/24/2022]
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Salvador GHM, Dreyer TR, Cavalcante WLG, Matioli FF, dos Santos JI, Velazquez-Campoy A, Gallacci M, Fontes MRM. Structural and functional evidence for membrane docking and disruption sites on phospholipase A2-like proteins revealed by complexation with the inhibitor suramin. ACTA ACUST UNITED AC 2015; 71:2066-78. [DOI: 10.1107/s1399004715014443] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/31/2015] [Indexed: 11/10/2022]
Abstract
Local myonecrosis resulting from snakebite envenomation is not efficiently neutralized by regular antivenom administration. This limitation is considered to be a significant health problem by the World Health Organization. Phospholipase A2-like (PLA2-like) proteins are among the most important proteins related to the muscle damage resulting from several snake venoms. However, despite their conserved tertiary structure compared with PLA2s, their biological mechanism remains incompletely understood. Different oligomeric conformations and binding sites have been identified or proposed, leading to contradictory data in the literature. In the last few years, a comprehensive hypothesis has been proposed based on fatty-acid binding, allosteric changes and the presence of two different interaction sites. In the present study, a combination of techniques were used to fully understand the structural–functional characteristics of the interaction between suramin and MjTX-II (a PLA2-like toxin).In vitroneuromuscular studies were performed to characterize the biological effects of the protein–ligand interaction and demonstrated that suramin neutralizes the myotoxic activity of MjTX-II. The high-resolution structure of the complex identified the toxin–ligand interaction sites. Calorimetric assays showed two different binding events between the protein and the inhibitor. It is demonstrated for the first time that the inhibitor binds to the surface of the toxin, obstructing the sites involved in membrane docking and disruption according to the proposed myotoxic mechanism. Furthermore, higher-order oligomeric formation by interaction with interfacial suramins was observed, which may also aid the inhibitory process. These results further substantiate the current myotoxic mechanism and shed light on the search for efficient inhibitors of the local myonecrosis phenomenon.
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Fernandes CAH, Cardoso FF, Cavalcante WGL, Soares AM, Dal-Pai M, Gallacci M, Fontes MRM. Structural Basis for the Inhibition of a Phospholipase A2-Like Toxin by Caffeic and Aristolochic Acids. PLoS One 2015; 10:e0133370. [PMID: 26192963 PMCID: PMC4508052 DOI: 10.1371/journal.pone.0133370] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 06/25/2015] [Indexed: 11/18/2022] Open
Abstract
One of the main challenges in toxicology today is to develop therapeutic alternatives for the treatment of snake venom injuries that are not efficiently neutralized by conventional serum therapy. Venom phospholipases A2 (PLA2s) and PLA2-like proteins play a fundamental role in skeletal muscle necrosis, which can result in permanent sequelae and disability. This leads to economic and social problems, especially in developing countries. In this work, we performed structural and functional studies with Piratoxin-I, a Lys49-PLA2 from Bothropspirajai venom, complexed with two compounds present in several plants used in folk medicine against snakebites. These ligands partially neutralized the myotoxic activity of PrTX-I towards binding on the two independent sites of interaction between Lys49-PLA2 and muscle membrane. Our results corroborate the previously proposed mechanism of action of PLA2s-like and provide insights for the design of structure-based inhibitors that could prevent the permanent injuries caused by these proteins in snakebite victims.
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Affiliation(s)
- Carlos A. H. Fernandes
- Dep. de Física e Biofísica, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, São Paulo, São Paulo, Brazil
| | - Fábio Florença Cardoso
- Dep. de Física e Biofísica, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, São Paulo, São Paulo, Brazil
- Dep. de Farmacologia, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Walter G. L. Cavalcante
- Dep. de Física e Biofísica, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, São Paulo, São Paulo, Brazil
- Dep. de Farmacologia, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Andreimar M. Soares
- Fundação Oswaldo Cruz (FIOCRUZ), Porto Velho, Rondônia, Brazil
- Centro de Estudos de Biomoléculas Aplicadas, Universidade Federal de Rondônia, Porto Velho, Rondônia, Brazil
| | - Maeli Dal-Pai
- Dep. de Morfologia, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Marcia Gallacci
- Dep. de Farmacologia, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Marcos R. M. Fontes
- Dep. de Física e Biofísica, Instituto de Biociências, UNESP–Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, São Paulo, São Paulo, Brazil
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da Silva GA, Domingos TFS, Fonseca RR, Sanchez EF, Teixeira VL, Fuly AL. The red seaweed Plocamium brasiliense shows anti-snake venom toxic effects. J Venom Anim Toxins Incl Trop Dis 2015; 21:2. [PMID: 25699078 PMCID: PMC4333883 DOI: 10.1186/s40409-015-0002-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/27/2015] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Snakebite is considered a neglected tropical disease by the World Health Organization. In Brazil, about 70% of the envenomation cases are caused by Bothrops snakes. Its venom may provoke hemorrhage, pain, necrosis, hemolysis, renal or cardiac failure and even death in victims. Since commercial antivenom does not efficiently neutralize the local toxic effects of venoms, natural products have been tested in order to provide alternative or complementary treatment to serum therapy. Therefore, the present study aimed to evaluate the ability of the seaweed Plocamium brasiliense and its active derivatives to neutralize hemorrhagic, edematogenic, hemolytic, coagulant and proteolytic activities of B. jararaca venom. METHODS Specimens of P. brasiliense were collected in Rio de Janeiro state, Brazil, dried and submitted to oil extraction using four solvents of increasing polarities, n-hexane (HEX), dichloromethane (DCM), ethyl acetate (ETA) and hydroalcoholic solution (HYD). The solvents were evaporated, yielding HEX, DCM, ETA and HYD extracts. Further, all extracts were dissolved in dimethylsulfoxide. In addition, two monoterpenes (8-bromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene and 1,8-dibromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene) and a cholesterol fraction were isolated from the extract of P. brasiliense prepared in hexane. Algal samples were incubated for 30 minutes with B. jararaca venom, and then tested for lethality; hemorrhagic, edematogenic, hemolytic, coagulant and proteolytic effects. RESULTS Most of the algal extracts inhibited the toxic effects with different potencies. The DCM extract was the most effective, since it inhibited all types of toxic activity. On the other hand, the HYD extract failed to inhibit any effect. Moreover, the isolated products inhibited proteolysis and protected mice from hemorrhage in 30% of the cases, whereas 8-bromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene inhibited 100% and 20% of the hemorrhagic and proteolytic activities, respectively. None of the algal products were toxic to mice. CONCLUSION Seaweeds may be a promising source of inhibitors against toxic effects caused by B. jararaca envenomation, which may contribute to antivenom treatment.
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Affiliation(s)
- Geisiane Alves da Silva
- />Department of Molecular and Cellular Biology, Institute of Biology, Federal Fluminense University (UFF), Niterói, Rio de Janeiro State Brazil
| | - Thaisa Francielle Souza Domingos
- />Department of Molecular and Cellular Biology, Institute of Biology, Federal Fluminense University (UFF), Niterói, Rio de Janeiro State Brazil
| | - Rainiomar Raimundo Fonseca
- />Department of Organic Chemistry, Institute of Chemistry, Federal Fluminense University (UFF), Niterói, Rio de Janeiro State Brazil
| | - Eladio Flores Sanchez
- />Laboratory of Biochemistry of Proteins from Animal Venoms, Research and Development Center, Ezequiel Dias Foundation, Belo Horizonte, Minas Gerais State Brazil
| | - Valéria Laneuville Teixeira
- />Department of Marine Biology, Institute of Biology, Federal Fluminense University (UFF), Niterói, Rio de Janeiro State Brazil
| | - André Lopes Fuly
- />Department of Molecular and Cellular Biology, Institute of Biology, Federal Fluminense University (UFF), Niterói, Rio de Janeiro State Brazil
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Fernandes CA, Borges RJ, Lomonte B, Fontes MR. A structure-based proposal for a comprehensive myotoxic mechanism of phospholipase A2-like proteins from viperid snake venoms. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:2265-76. [DOI: 10.1016/j.bbapap.2014.09.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 09/09/2014] [Accepted: 09/16/2014] [Indexed: 01/21/2023]
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Huancahuire-Vega S, Ponce-Soto LA, Marangoni S. PhTX-II a basic myotoxic phospholipase A₂ from Porthidium hyoprora snake venom, pharmacological characterization and amino acid sequence by mass spectrometry. Toxins (Basel) 2014; 6:3077-97. [PMID: 25365526 PMCID: PMC4247251 DOI: 10.3390/toxins6113077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 01/10/2023] Open
Abstract
A monomeric basic PLA₂ (PhTX-II) of 14149.08 Da molecular weight was purified to homogeneity from Porthidium hyoprora venom. Amino acid sequence by in tandem mass spectrometry revealed that PhTX-II belongs to Asp49 PLA₂ enzyme class and displays conserved domains as the catalytic network, Ca²⁺-binding loop and the hydrophobic channel of access to the catalytic site, reflected in the high catalytic activity displayed by the enzyme. Moreover, PhTX-II PLA₂ showed an allosteric behavior and its enzymatic activity was dependent on Ca²⁺. Examination of PhTX-II PLA₂ by CD spectroscopy indicated a high content of alpha-helical structures, similar to the known structure of secreted phospholipase IIA group suggesting a similar folding. PhTX-II PLA₂ causes neuromuscular blockade in avian neuromuscular preparations with a significant direct action on skeletal muscle function, as well as, induced local edema and myotoxicity, in mice. The treatment of PhTX-II by BPB resulted in complete loss of their catalytic activity that was accompanied by loss of their edematogenic effect. On the other hand, enzymatic activity of PhTX-II contributes to this neuromuscular blockade and local myotoxicity is dependent not only on enzymatic activity. These results show that PhTX-II is a myotoxic Asp49 PLA₂ that contributes with toxic actions caused by P. hyoprora venom.
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Affiliation(s)
- Salomón Huancahuire-Vega
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil.
| | - Luis Alberto Ponce-Soto
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil.
| | - Sergio Marangoni
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil.
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Mora-Obando D, Díaz C, Angulo Y, Gutiérrez JM, Lomonte B. Role of enzymatic activity in muscle damage and cytotoxicity induced by Bothrops asper Asp49 phospholipase A2 myotoxins: are there additional effector mechanisms involved? PeerJ 2014; 2:e569. [PMID: 25276503 PMCID: PMC4178460 DOI: 10.7717/peerj.569] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/20/2014] [Indexed: 01/15/2023] Open
Abstract
Viperid venoms often contain mixtures of Asp49 and Lys49 PLA2 myotoxin isoforms, relevant to development of myonecrosis. Given their difference in catalytic activity, mechanistic studies on each type require highly purified samples. Studies on Asp49 PLA2s have shown that enzyme inactivation using p-bromophenacyl bromide (p-BPB) drastically affects toxicity. However, based on the variable levels of residual toxicity observed in some studies, it has been suggested that effector mechanisms independent of catalysis may additionally be involved in the toxicity of these enzymes, possibly resembling those of the enzymatically inactive Lys49 myotoxins. A possibility that Lys49 isoforms could be present in Asp49 PLA2 preparations exists and, if undetected in previous studies, could explain the variable residual toxicity. This question is here addressed by using an enzyme preparation ascertained to be free of Lys49 myotoxins. In agreement with previous reports, inactivation of the catalytic activity of an Asp49 myotoxin preparation led to major inhibition of toxic effects in vitro and in vivo. The very low residual levels of myotoxicity (7%) and cytotoxicity (4%) observed can be attributed to the low, although detectable, enzyme remaining active after p-BPB treatment (2.7%), and would be difficult to reconcile with the proposed existence of additional catalytic-independent toxic mechanisms. These findings favor the concept that the effector mechanism of toxicity of Asp49 PLA2 myotoxins from viperids fundamentally relies on their ability to hydrolyze phospholipids, arguing against the proposal that membrane disruption may also be caused by additional mechanisms that are independent of catalysis.
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Affiliation(s)
- Diana Mora-Obando
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica , San José , Costa Rica
| | - Cecilia Díaz
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica , San José , Costa Rica ; Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica , San José , Costa Rica
| | - Yamileth Angulo
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica , San José , Costa Rica
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica , San José , Costa Rica
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica , San José , Costa Rica
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