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Bittenbinder MA, van Thiel J, Cardoso FC, Casewell NR, Gutiérrez JM, Kool J, Vonk FJ. Tissue damaging toxins in snake venoms: mechanisms of action, pathophysiology and treatment strategies. Commun Biol 2024; 7:358. [PMID: 38519650 PMCID: PMC10960010 DOI: 10.1038/s42003-024-06019-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/07/2024] [Indexed: 03/25/2024] Open
Abstract
Snakebite envenoming is an important public health issue responsible for mortality and severe morbidity. Where mortality is mainly caused by venom toxins that induce cardiovascular disturbances, neurotoxicity, and acute kidney injury, morbidity is caused by toxins that directly or indirectly destroy cells and degrade the extracellular matrix. These are referred to as 'tissue-damaging toxins' and have previously been classified in various ways, most of which are based on the tissues being affected (e.g., cardiotoxins, myotoxins). This categorisation, however, is primarily phenomenological and not mechanistic. In this review, we propose an alternative way of classifying cytotoxins based on their mechanistic effects rather than using a description that is organ- or tissue-based. The mechanisms of toxin-induced tissue damage and their clinical implications are discussed. This review contributes to our understanding of fundamental biological processes associated with snakebite envenoming, which may pave the way for a knowledge-based search for novel therapeutic options.
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Affiliation(s)
- Mátyás A Bittenbinder
- Naturalis Biodiversity Center, 2333 CR, Leiden, The Netherlands
- AIMMS, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV, Amsterdam, The Netherlands
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, The Netherlands
| | - Jory van Thiel
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, Liverpool, United Kingdom
- Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Howard Hughes Medical Institute and Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Fernanda C Cardoso
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
- Centre for Innovations in Peptide and Protein Science, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, Liverpool, United Kingdom
| | - José-María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, 11501, Costa Rica.
| | - Jeroen Kool
- AIMMS, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV, Amsterdam, The Netherlands.
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, The Netherlands.
| | - Freek J Vonk
- Naturalis Biodiversity Center, 2333 CR, Leiden, The Netherlands
- AIMMS, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV, Amsterdam, The Netherlands
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, The Netherlands
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Cardoso FF, Salvador GHM, Cavalcante WLG, Dal-Pai M, Fontes MRDM. BthTX-I, a phospholipase A 2-like toxin, is inhibited by the plant cinnamic acid derivative: chlorogenic acid. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2024; 1872:140988. [PMID: 38142025 DOI: 10.1016/j.bbapap.2023.140988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
Snakebite is a significant health concern in tropical and subtropical regions, particularly in Africa, Asia, and Latin America, resulting in more than 2.7 million envenomations and an estimated one hundred thousand fatalities annually. The Bothrops genus is responsible for the majority of snakebite envenomings in Latin America and Caribbean countries. Accidents involving snakes from this genus are characterized by local symptoms that often lead to permanent sequelae and death. However, specific antivenoms exhibit limited effectiveness in inhibiting local tissue damage. Phospholipase A2-like (PLA2-like) toxins emerge as significant contributors to local myotoxicity in accidents involving Bothrops species. As a result, they represent a crucial target for prospective treatments. Some natural and synthetic compounds have shown the ability to reduce or abolish the myotoxic effects of PLA2-like proteins. In this study, we employed a combination approach involving myographic, morphological, biophysical and bioinformatic techniques to investigate the interaction between chlorogenic acid (CGA) and BthTX-I, a PLA2-like toxin. CGA provided a protection of 71.8% on muscle damage in a pre-incubation treatment. Microscale thermophoresis and circular dichroism experiments revealed that CGA interacted with the BthTX-I while preserving its secondary structure. CGA exhibited an affinity to the toxin that ranks among the highest observed for a natural compound. Bioinformatics simulations indicated that CGA inhibitor binds to the toxin's hydrophobic channel in a manner similar to other phenolic compounds previously investigated. These findings suggest that CGA interferes with the allosteric transition of the non-activated toxin, and the stability of the dimeric assembly of its activated state.
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Affiliation(s)
- Fábio Florença Cardoso
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | | | - Walter Luís Garrido Cavalcante
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Maeli Dal-Pai
- Departamento de Biologia Estrutural e Funcional, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Marcos Roberto de Mattos Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Instituto de Estudos Avançados do Mar (IEAMar), Universidade Estadual Paulista (UNESP), São Vicente, SP, Brazil.
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Castro-Amorim J, Novo de Oliveira A, Da Silva SL, Soares AM, Mukherjee AK, Ramos MJ, Fernandes PA. Catalytically Active Snake Venom PLA 2 Enzymes: An Overview of Its Elusive Mechanisms of Reaction. J Med Chem 2023; 66:5364-5376. [PMID: 37018514 PMCID: PMC10150362 DOI: 10.1021/acs.jmedchem.3c00097] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Snake venom-secreted phospholipase A2 (svPLA2) enzymes, both catalytically active and inactive, are a central component in envenoming. These are responsible for disrupting the cell membrane's integrity, inducing a wide range of pharmacological effects, such as the necrosis of the bitten limb, cardiorespiratory arrest, edema, and anticoagulation. Although extensively characterized, the reaction mechanisms of enzymatic svPLA2 are still to be thoroughly understood. This review presents and analyses the most plausible reaction mechanisms for svPLA2, such as the "single-water mechanism" or the "assisted-water mechanism" initially proposed for the homologous human PLA2. All of the mechanistic possibilities are characterized by a highly conserved Asp/His/water triad and a Ca2+ cofactor. The extraordinary increase in activity induced by binding to a lipid-water interface, known as "interfacial activation," critical for the PLA2s activity, is also discussed. Finally, a potential catalytic mechanism for the postulated noncatalytic PLA2-like proteins is anticipated.
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Affiliation(s)
- Juliana Castro-Amorim
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Ana Novo de Oliveira
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Saulo Luís Da Silva
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Andreimar M Soares
- Laboratory of Biotechnology of Proteins and Bioactive Compounds (LABIOPROT), Oswaldo Cruz Foundation, National Institute of Epidemiology in the Western Amazon (INCT-EpiAmO), Porto Velho, Rondônia 76812-245, Brazil
- Sao Lucas Universitary Center (UniSL), Porto Velho, Rondônia 76805-846, Brazil
| | - Ashis K Mukherjee
- Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam, India
- Division of Life Sciences, Institute of Advanced Studies in Science and Technology, Vigyan Path, Garchuk, Paschim Boragaon, Guwahati 781035, Assam, India
| | - Maria João Ramos
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Pedro A Fernandes
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
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Salvador GHM, Pinto ÊKR, Ortolani PL, Fortes-Dias CL, Cavalcante WLG, Soares AM, Lomonte B, Lewin MR, Fontes MRM. Structural basis of the myotoxic inhibition of the Bothrops pirajai PrTX-I by the synthetic varespladib. Biochimie 2023; 207:1-10. [PMID: 36403756 DOI: 10.1016/j.biochi.2022.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Varespladib (LY315920) is a potent inhibitor of human group IIA phospholipase A2 (PLA2) originally developed to control inflammatory cascades of diseases associated with high or dysregulated levels of endogenous PLA2. Recently, varespladib was also found to inhibit snake venom PLA2 and PLA2-like toxins. Herein, ex vivo neuromuscular blocking activity assays were used to test the inhibitory activity of varespladib. The binding affinity between varespladib and a PLA2-like toxin was quantified and compared with other potential inhibitors for this class of proteins. Crystallographic and bioinformatic studies showed that varespladib binds to PrTX-I and BthTX-I into their hydrophobic channels, similarly to other previously characterized PLA2-like myotoxins. However, a new finding is that an additional varespladib binds to the MDiS region, a particular site that is related to muscle cell disruption by these toxins. The present results further advance the characterization of the molecular interactions of varespladib with PLA2-like myotoxins and provide additional evidence for this compound as a promising inhibitor candidate for different PLA2 and PLA2-like toxins.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Êmylle K R Pinto
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Paula L Ortolani
- Centro de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias (FUNED), Brazil
| | | | - Walter L G Cavalcante
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Andreimar M Soares
- Laboratório de Biotecnologia de Proteínas e Compostos Bioativos Aplicados à Saúde, LABIOPROT, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia e Instituto Nacional de Ciência e Tecnologia de Epidemiologia da Amazônia Ocidental, INCT EPIAMO, Porto Velho, RO, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- Ophirex, Inc. Corte Madera, CA, 94925, USA; 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, Botucatu, SP, Brazil.
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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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Lomonte B. Lys49 myotoxins, secreted phospholipase A 2-like proteins of viperid venoms: A comprehensive review. Toxicon 2023; 224:107024. [PMID: 36632869 DOI: 10.1016/j.toxicon.2023.107024] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/06/2023] [Accepted: 01/06/2023] [Indexed: 01/11/2023]
Abstract
Muscle necrosis is a potential clinical complication of snakebite envenomings, which in severe cases can lead to functional or physical sequelae such as disability or amputation. Snake venom proteins with the ability to directly damage skeletal muscle fibers are collectively referred to as myotoxins, and include three main types: cytolysins of the "three-finger toxin" protein family expressed in many elapid venoms, the so-called "small" myotoxins found in a number of rattlesnake venoms, and the widespread secreted phospholipase A2 (sPLA2) molecules. Among the latter, protein variants that conserve the sPLA2 structure, but lack such enzymatic activity, have been increasingly found in the venoms of many viperid species. Intriguingly, these sPLA2-like proteins are able to induce muscle necrosis by a mechanism independent of phospholipid hydrolysis. They are commonly referred to as "Lys49 myotoxins" since they most often present, among other substitutions, the replacement of the otherwise invariant residue Asp49 of sPLA2s by Lys. This work comprehensively reviews the historical developments and current knowledge towards deciphering the mechanism of action of Lys49 sPLA2-like myotoxins, and points out main gaps to be filled for a better understanding of these multifaceted snake venom proteins, to hopefully lead to improved treatments for snakebites.
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Affiliation(s)
- Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, 11501, Costa Rica.
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Nicholls RA, Wojdyr M, Joosten RP, Catapano L, Long F, Fischer M, Emsley P, Murshudov GN. The missing link: covalent linkages in structural models. Acta Crystallogr D Struct Biol 2021; 77:727-745. [PMID: 34076588 PMCID: PMC8171067 DOI: 10.1107/s2059798321003934] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
Covalent linkages between constituent blocks of macromolecules and ligands have been subject to inconsistent treatment during the model-building, refinement and deposition process. This may stem from a number of sources, including difficulties with initially detecting the covalent linkage, identifying the correct chemistry, obtaining an appropriate restraint dictionary and ensuring its correct application. The analysis presented herein assesses the extent of problems involving covalent linkages in the Protein Data Bank (PDB). Not only will this facilitate the remediation of existing models, but also, more importantly, it will inform and thus improve the quality of future linkages. By considering linkages of known type in the CCP4 Monomer Library (CCP4-ML), failure to model a covalent linkage is identified to result in inaccurate (systematically longer) interatomic distances. Scanning the PDB for proximal atom pairs that do not have a corresponding type in the CCP4-ML reveals a large number of commonly occurring types of unannotated potential linkages; in general, these may or may not be covalently linked. Manual consideration of the most commonly occurring cases identifies a number of genuine classes of covalent linkages. The recent expansion of the CCP4-ML is discussed, which has involved the addition of over 16 000 and the replacement of over 11 000 component dictionaries using AceDRG. As part of this effort, the CCP4-ML has also been extended using AceDRG link dictionaries for the aforementioned linkage types identified in this analysis. This will facilitate the identification of such linkage types in future modelling efforts, whilst concurrently easing the process involved in their application. The need for a universal standard for maintaining link records corresponding to covalent linkages, and references to the associated dictionaries used during modelling and refinement, following deposition to the PDB is emphasized. The importance of correctly modelling covalent linkages is demonstrated using a case study, which involves the covalent linkage of an inhibitor to the main protease in various viral species, including SARS-CoV-2. This example demonstrates the importance of properly modelling covalent linkages using a comprehensive restraint dictionary, as opposed to just using a single interatomic distance restraint or failing to model the covalent linkage at all.
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Affiliation(s)
- Robert A. Nicholls
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Marcin Wojdyr
- Global Phasing Limited, Sheraton House, Castle Park, Cambridge CB3 0AX, United Kingdom
| | - Robbie P. Joosten
- Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- Oncode Institute, The Netherlands
| | - Lucrezia Catapano
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
- Randall Centre for Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King’s College London, London SE1 9RT, United Kingdom
| | - Fei Long
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Marcus Fischer
- Chemical Biology and Therapeutics and Structural Biology, St Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
| | - Paul Emsley
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Garib N. Murshudov
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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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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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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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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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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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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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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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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15
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Cardoso FF, Borges RJ, Dreyer TR, Salvador GH, Cavalcante WL, Pai MD, Gallacci M, Fontes MR. Structural basis of phospholipase A2-like myotoxin inhibition by chicoric acid, a novel potent inhibitor of ophidian toxins. Biochim Biophys Acta Gen Subj 2018; 1862:2728-2737. [DOI: 10.1016/j.bbagen.2018.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/30/2018] [Accepted: 08/01/2018] [Indexed: 10/28/2022]
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16
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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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17
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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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18
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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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19
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Koike R, Amemiya T, Horii T, Ota M. Structural changes of homodimers in the PDB. J Struct Biol 2017; 202:42-50. [PMID: 29233747 DOI: 10.1016/j.jsb.2017.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/30/2017] [Accepted: 12/08/2017] [Indexed: 01/25/2023]
Abstract
Protein complexes are involved in various biological phenomena. These complexes are intrinsically flexible, and structural changes are essential to their functions. To perform a large-scale automated analysis of the structural changes of complexes, we combined two original methods. An application, SCPC, compares two structures of protein complexes and decides the match of binding mode. Another application, Motion Tree, identifies rigid-body motions in various sizes and magnitude from the two structural complexes with the same binding mode. This approach was applied to all available homodimers in the Protein Data Bank (PDB). We defined two complex-specific motions: interface motion and subunit-spanning motion. In the former, each subunit of a complex constitutes a rigid body, and the relative movement between subunits occurs at the interface. In the latter, structural parts from distinct subunits constitute a rigid body, providing the relative movement spanning subunits. All structural changes were classified and examined. It was revealed that the complex-specific motions were common in the homodimers, detected in around 40% of families. The dimeric interfaces were likely to be small and flat for interface motion, while large and rugged for subunit-spanning motion. Interface motion was accompanied by a drastic change in contacts at the interface, while the change in the subunit-spanning motion was moderate. These results indicate that the interface properties of homodimers correlated with the type of complex-specific motion. The study demonstrates that the pipeline of SCPC and Motion Tree is useful for the massive analysis of structural change of protein complexes.
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Affiliation(s)
- Ryotaro Koike
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takayuki Amemiya
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Tatsuya Horii
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Motonori Ota
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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20
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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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21
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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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22
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Jia Y, Ermolinsky B, Garza A, Provenzano D. Phospholipase A2 in the venom of three cottonmouth snakes. Toxicon 2017. [DOI: 10.1016/j.toxicon.2017.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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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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24
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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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25
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Almeida J, Lancellotti M, Soares A, Calderon L, Ramírez D, González W, Marangoni S, Da Silva S. CoaTx-II, a new dimeric Lys49 phospholipase A2 from Crotalus oreganus abyssus snake venom with bactericidal potential: Insights into its structure and biological roles. Toxicon 2016; 120:147-58. [DOI: 10.1016/j.toxicon.2016.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/05/2016] [Accepted: 08/11/2016] [Indexed: 01/01/2023]
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26
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Corrêa EA, Kayano AM, Diniz-Sousa R, Setúbal SS, Zanchi FB, Zuliani JP, Matos NB, Almeida JR, Resende LM, Marangoni S, da Silva SL, Soares AM, Calderon LA. Isolation, structural and functional characterization of a new Lys49 phospholipase A2 homologue from Bothrops neuwiedi urutu with bactericidal potential. Toxicon 2016; 115:13-21. [DOI: 10.1016/j.toxicon.2016.02.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/16/2016] [Accepted: 02/24/2016] [Indexed: 11/16/2022]
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27
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Prado NDR, Pereira SS, da Silva MP, Morais MSS, Kayano AM, Moreira-Dill LS, Luiz MB, Zanchi FB, Fuly AL, E. F. Huacca M, Fernandes CF, Calderon LA, Zuliani JP, Pereira da Silva LH, Soares AM, Stabeli RG, F. C. Fernandes C. Inhibition of the Myotoxicity Induced by Bothrops jararacussu Venom and Isolated Phospholipases A2 by Specific Camelid Single-Domain Antibody Fragments. PLoS One 2016; 11:e0151363. [PMID: 27028872 PMCID: PMC4814101 DOI: 10.1371/journal.pone.0151363] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/27/2016] [Indexed: 02/07/2023] Open
Abstract
Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH) with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II), two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs) and immunoglobulin frameworks (FRs) of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718) were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607) neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I) in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem.
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Affiliation(s)
| | | | | | | | | | | | - Marcos B. Luiz
- Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho-RO, Brazil
| | | | - André L. Fuly
- Universidade Federal Fluminense, UFF, Rio de Janeiro-RJ, Brazil
| | | | | | - Leonardo A. Calderon
- Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho-RO, Brazil
- Universidade Federal de Rondônia, UNIR, Porto Velho-RO, Brazil
| | - Juliana P. Zuliani
- Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho-RO, Brazil
- Universidade Federal de Rondônia, UNIR, Porto Velho-RO, Brazil
| | | | | | - Rodrigo G. Stabeli
- Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho-RO, Brazil
- Universidade Federal de Rondônia, UNIR, Porto Velho-RO, Brazil
| | - Carla F. C. Fernandes
- Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho-RO, Brazil
- Centro de Pesquisa em Medicina Tropical, CEPEM, Porto Velho-RO, Brazil
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28
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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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29
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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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Shukla PK, Gautam L, Sinha M, Kaur P, Sharma S, Singh TP. Structures and binding studies of the complexes of phospholipase A2 with five inhibitors. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1854:269-77. [PMID: 25541253 DOI: 10.1016/j.bbapap.2014.12.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/01/2014] [Accepted: 12/16/2014] [Indexed: 11/25/2022]
Abstract
Phospholipase A2 (PLA2) catalyzes the hydrolysis of phospholipids into arachidonic acid and lysophospholipids. Arachidonic acid is used as a substrate in the next step of the multistep pathway leading to the production of eicosanoids. The eicosanoids, in extremely low concentrations, are required in a number of physiological processes. However, the increase in their concentrations above the essential physiological requirements leads to various inflammatory conditions. In order to prevent the unwanted rise in the concentrations of eicosanoids, the actions of PLA2 and other enzymes of the pathway need to be blocked. We report here the structures of five complexes of group IIA PLA2 from Daboia russelli pulchella with tightly binding inhibitors, (i) p-coumaric acid, (ii) resveratrol, (iii) spermidine, (iv) corticosterone and (v) gramine derivative. The binding studies using fluorescence spectroscopy and surface plasmon resonance techniques for the interactions of PLA2 with the above five compounds showed high binding affinities with values of dissociation constants (KD) ranging from 3.7×10(-8) M to 2.1×10(-9) M. The structure determinations of the complexes of PLA2 with the above five compounds showed that all the compounds bound to PLA2 in the substrate binding cleft. The protein residues that contributed to the interactions with these compounds included Leu2, Leu3, Phe5, Gly6, Ile9, Ala18, Ile19, Trp22, Ser23, Cys29, Gly30, Cys45, His48, Asp49 and Phe106. The positions of side chains of several residues including Leu2, Leu3, Ile19, Trp31, Lys69, Ser70 and Arg72 got significantly shifted while the positions of active site residues, His48, Asp49, Tyr52 and Asp99 were unperturbed.
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Affiliation(s)
- Prakash Kumar Shukla
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Lovely Gautam
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Mau Sinha
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Sujata Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Tej P Singh
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
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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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Mora-Obando D, Fernández J, Montecucco C, Gutiérrez JM, Lomonte B. Synergism between basic Asp49 and Lys49 phospholipase A2 myotoxins of viperid snake venom in vitro and in vivo. PLoS One 2014; 9:e109846. [PMID: 25290688 PMCID: PMC4188610 DOI: 10.1371/journal.pone.0109846] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/02/2014] [Indexed: 11/19/2022] Open
Abstract
Two subtypes of phospholipases A2 (PLA2s) with the ability to induce myonecrosis, ‘Asp49’ and ‘Lys49’ myotoxins, often coexist in viperid snake venoms. Since the latter lack catalytic activity, two different mechanisms are involved in their myotoxicity. A synergism between Asp49 and Lys49 myotoxins from Bothrops asper was previously observed in vitro, enhancing Ca2+ entry and cell death when acting together upon C2C12 myotubes. These observations are extended for the first time in vivo, by demonstrating a clear enhancement of myonecrosis by the combined action of these two toxins in mice. In addition, novel aspects of their synergism were revealed using myotubes. Proportions of Asp49 myotoxin as low as 0.1% of the Lys49 myotoxin are sufficient to enhance cytotoxicity of the latter, but not the opposite. Sublytic amounts of Asp49 myotoxin also enhanced cytotoxicity of a synthetic peptide encompassing the toxic region of Lys49 myotoxin. Asp49 myotoxin rendered myotubes more susceptible to osmotic lysis, whereas Lys49 myotoxin did not. In contrast to myotoxic Asp49 PLA2, an acidic non-toxic PLA2 from the same venom did not markedly synergize with Lys49 myotoxin, revealing a functional difference between basic and acidic PLA2 enzymes. It is suggested that Asp49 myotoxins synergize with Lys49 myotoxins by virtue of their PLA2 activity. In addition to the membrane-destabilizing effect of this activity, Asp49 myotoxins may generate anionic patches of hydrolytic reaction products, facilitating electrostatic interactions with Lys49 myotoxins. These data provide new evidence for the evolutionary adaptive value of the two subtypes of PLA2 myotoxins acting synergistically in viperid venoms.
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Affiliation(s)
- Diana Mora-Obando
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Julián Fernández
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
- * E-mail:
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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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Xu Z, Yang Z, Liu Y, Lu Y, Chen K, Zhu W. Halogen Bond: Its Role beyond Drug–Target Binding Affinity for Drug Discovery and Development. J Chem Inf Model 2014; 54:69-78. [DOI: 10.1021/ci400539q] [Citation(s) in RCA: 237] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Zhijian Xu
- Drug
Discovery and Design Center, Key Laboratory of Receptor Research,
State Key Laboratory of Drug Research, Shanghai Institute of Materia
Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zhuo Yang
- Drug
Discovery and Design Center, Key Laboratory of Receptor Research,
State Key Laboratory of Drug Research, Shanghai Institute of Materia
Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yingtao Liu
- Drug
Discovery and Design Center, Key Laboratory of Receptor Research,
State Key Laboratory of Drug Research, Shanghai Institute of Materia
Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yunxiang Lu
- Department
of Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Kaixian Chen
- Drug
Discovery and Design Center, Key Laboratory of Receptor Research,
State Key Laboratory of Drug Research, Shanghai Institute of Materia
Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Weiliang Zhu
- Drug
Discovery and Design Center, Key Laboratory of Receptor Research,
State Key Laboratory of Drug Research, Shanghai Institute of Materia
Medica, Chinese Academy of Sciences, Shanghai, 201203, China
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Fernandes CA, Comparetti EJ, Borges RJ, Huancahuire-Vega S, Ponce-Soto LA, Marangoni S, Soares AM, Fontes MR. Structural bases for a complete myotoxic mechanism: Crystal structures of two non-catalytic phospholipases A2-like from Bothrops brazili venom. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2772-81. [DOI: 10.1016/j.bbapap.2013.10.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/07/2013] [Accepted: 10/12/2013] [Indexed: 11/16/2022]
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Snake venom PLA2s inhibitors isolated from Brazilian plants: synthetic and natural molecules. BIOMED RESEARCH INTERNATIONAL 2013; 2013:153045. [PMID: 24171158 PMCID: PMC3793501 DOI: 10.1155/2013/153045] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/19/2013] [Indexed: 01/21/2023]
Abstract
Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.
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Linear B-cell epitopes in BthTX-1, BthTX-II and BthA-1, phospholipase A2's from Bothrops jararacussu snake venom, recognized by therapeutically neutralizing commercial horse antivenom. Toxicon 2013; 72:90-101. [DOI: 10.1016/j.toxicon.2013.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/22/2013] [Accepted: 06/11/2013] [Indexed: 11/18/2022]
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38
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Salvador GH, Cavalcante WL, dos Santos JI, Gallacci M, Soares AM, Fontes MR. Structural and functional studies with mytoxin II from Bothrops moojeni reveal remarkable similarities and differences compared to other catalytically inactive phospholipases A2-like. Toxicon 2013; 72:52-63. [DOI: 10.1016/j.toxicon.2013.06.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/16/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
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Salvador GHM, Fernandes CAH, Magro AJ, Marchi-Salvador DP, Cavalcante WLG, Fernandez RM, Gallacci M, Soares AM, Oliveira CLP, Fontes MRM. Structural and phylogenetic studies with MjTX-I reveal a multi-oligomeric toxin--a novel feature in Lys49-PLA2s protein class. PLoS One 2013; 8:e60610. [PMID: 23573271 PMCID: PMC3616104 DOI: 10.1371/journal.pone.0060610] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 02/28/2013] [Indexed: 11/19/2022] Open
Abstract
The mortality caused by snakebites is more damaging than many tropical diseases, such as dengue haemorrhagic fever, cholera, leishmaniasis, schistosomiasis and Chagas disease. For this reason, snakebite envenoming adversely affects health services of tropical and subtropical countries and is recognized as a neglected disease by the World Health Organization. One of the main components of snake venoms is the Lys49-phospholipases A2, which is catalytically inactive but possesses other toxic and pharmacological activities. Preliminary studies with MjTX-I from Bothrops moojeni snake venom revealed intriguing new structural and functional characteristics compared to other bothropic Lys49-PLA2s. We present in this article a comprehensive study with MjTX-I using several techniques, including crystallography, small angle X-ray scattering, analytical size-exclusion chromatography, dynamic light scattering, myographic studies, bioinformatics and molecular phylogenetic analyses.Based in all these experiments we demonstrated that MjTX-I is probably a unique Lys49-PLA2, which may adopt different oligomeric forms depending on the physical-chemical environment. Furthermore, we showed that its myotoxic activity is dramatically low compared to other Lys49-PLA2s, probably due to the novel oligomeric conformations and important mutations in the C-terminal region of the protein. The phylogenetic analysis also showed that this toxin is clearly distinct from other bothropic Lys49-PLA2s, in conformity with the peculiar oligomeric characteristics of MjTX-I and possible emergence of new functionalities inresponse to environmental changes and adaptation to new preys.
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Affiliation(s)
- Guilherme H. M. Salvador
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
| | - Carlos A. H. Fernandes
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
| | - Angelo J. Magro
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
| | - Daniela P. Marchi-Salvador
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
| | - Walter L. G. Cavalcante
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
- Depto. de Farmacologia, Universidade Estadual Paulista – UNESP, Botucatu, SP, Brazil
| | - Roberto M. Fernandez
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
| | - Márcia Gallacci
- Depto. de Farmacologia, Universidade Estadual Paulista – UNESP, Botucatu, SP, Brazil
| | - Andreimar M. Soares
- Fundação Oswaldo Cruz – FIOCRUZ Rondônia and Centro de Estudos de Biomoléculas Aplicadas – CEBio, Universidade Federal de Rondônia – UNIR, Porto Velho, RO, Brazil
| | - Cristiano L. P. Oliveira
- Depto. de Física Experimental, Instituto de Física, Universidade de São Paulo – USP, São Paulo, SP, Brazil
| | - Marcos R. M. Fontes
- Depto. de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista–UNESP, Botucatu, SP, Brazil
- * E-mail:
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Fernandes CAH, Gartuzo ECG, Pagotto I, Comparetti EJ, Huancahuire-Vega S, Ponce-Soto LA, Costa TR, Marangoni S, Soares AM, Fontes MRM. Crystallization and preliminary X-ray diffraction analysis of three myotoxic phospholipases A2 from Bothrops brazili venom. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:935-8. [PMID: 22869126 PMCID: PMC3412777 DOI: 10.1107/s1744309112026073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 06/08/2012] [Indexed: 11/10/2022]
Abstract
Two myotoxic and noncatalytic Lys49-phospholipases A(2) (braziliantoxin-II and MT-II) and a myotoxic and catalytic phospholipase A(2) (braziliantoxin-III) from the venom of the Amazonian snake Bothrops brazili were crystallized. The crystals diffracted to resolutions in the range 2.56-2.05 Å and belonged to space groups P3(1)21 (braziliantoxin-II), P6(5)22 (braziliantoxin-III) and P2(1) (MT-II). The structures were solved by molecular-replacement techniques. Both of the Lys49-phospholipases A(2) (braziliantoxin-II and MT-II) contained a dimer in the asymmetric unit, while the Asp49-phospholipase A(2) braziliantoxin-III contained a monomer in its asymmetric unit. Analysis of the quaternary assemblies of the braziliantoxin-II and MT-II structures using the PISA program indicated that both models have a dimeric conformation in solution. The same analysis of the braziliantoxin-III structure indicated that this protein does not dimerize in solution and probably acts as a monomer in vivo, similar to other snake-venom Asp49-phospholipases A(2).
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Affiliation(s)
- Carlos A. H. Fernandes
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP and Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
| | - Elaine C. G. Gartuzo
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP and Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
| | - Ivan Pagotto
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP and Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
| | - Edson J. Comparetti
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP and Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
| | - Salomón Huancahuire-Vega
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas-SP, Brazil
| | - Luis Alberto Ponce-Soto
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas-SP, Brazil
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas-SP, Brazil
| | - Tássia R. Costa
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, FCFRP, USP, Ribeirão Preto-SP, Brazil
| | - Sergio Marangoni
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas-SP, Brazil
| | - Andreimar M. Soares
- Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Centro de Estudos de Biomoléculas Aplicadas, Universidade Federal de Rondônia, Porto Velho-RO, Brazil
| | - Marcos R. M. Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP and Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
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dos Santos JI, Cardoso FF, Soares AM, dal Pai Silva M, Gallacci M, Fontes MRM. Structural and functional studies of a bothropic myotoxin complexed to rosmarinic acid: new insights into Lys49-PLA₂ inhibition. PLoS One 2011; 6:e28521. [PMID: 22205953 PMCID: PMC3244394 DOI: 10.1371/journal.pone.0028521] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 11/09/2011] [Indexed: 11/18/2022] Open
Abstract
Snakebite envenoming is an important public health problem in many tropical and subtropical countries, and is considered a neglected tropical disease by the World Health Organization. Most severe cases are inflicted by species of the families Elapidae and Viperidae, and lead to a number of systemic and local effects in the victim. One of the main problems regarding viperidic accidents is prominent local tissue damage whose pathogenesis is complex and involves the combined actions of a variety of venom components. Phospholipases A₂ (PLA₂s) are the most abundant muscle-damaging components of these venoms. Herein, we report functional and structural studies of PrTX-I, a Lys49-PLA₂ from Bothops pirajai snake venom, and the influence of rosmarinic acid (RA) upon this toxin's activities. RA is a known active component of some plant extracts and has been reported as presenting anti-myotoxic properties related to bothopic envenomation. The myotoxic activity of Lys49-PLA₂s is well established in the literature and although no in vivo neurotoxicity has been observed among these toxins, in vitro neuromuscular blockade has been reported for some of these proteins. Our in vitro studies show that RA drastically reduces both the muscle damage and the neuromuscular blockade exerted by PrTX-I on mice neuromuscular preparations (by ∼80% and ∼90%, respectively). These results support the hypothesis that the two effects are closely related and lead us to suggest that they are consequences of the muscle membrane-destabilizing activity of the Lys49-PLA₂. Although the C-terminal region of these proteins has been reported to comprise the myotoxic site, we demonstrate by X-ray crystallographic studies that RA interacts with PrTX-I in a different region. Consequently, a new mode of Lys49-PLA₂ inhibition is proposed. Comparison of our results with others in the literature suggests possible new ways to inhibit bothropic snake venom myotoxins and improve serum therapy.
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Affiliation(s)
- Juliana I. dos Santos
- Departamento de Física e Biofísica, Instituto de Biociências, University Estadual Paulista, Botucatu/Sao Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Botucatu/Sao Paulo, Brazil
| | - Fábio F. Cardoso
- Departamento de Farmacologia, Instituto de Biociências, University Estadual Paulista, Botucatu/Sao Paulo, Brazil
| | - Andreimar M. Soares
- Fundação Oswaldo Cruz - Rondônia and Centro de Estudos de Biomoléculas Aplicadas, Universidade Federal de Rondônia, Porto Velho/Rondonia, Brazil
| | - Maeli dal Pai Silva
- Departamento de Morfologia, Instituto de Biociências, University Estadual Paulista, Botucatu/Sao Paulo, Brazil
| | - Márcia Gallacci
- Departamento de Farmacologia, Instituto de Biociências, University Estadual Paulista, Botucatu/Sao Paulo, Brazil
| | - Marcos R. M. Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, University Estadual Paulista, Botucatu/Sao Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Botucatu/Sao Paulo, Brazil
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Dileep KV, Tintu I, Mandal PK, Karthe P, Haridas M, Sadasivan C. Binding to PLA2 May Contribute to the Anti-Inflammatory Activity of Catechol. Chem Biol Drug Des 2011; 79:143-7. [PMID: 21995306 DOI: 10.1111/j.1747-0285.2011.01258.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kalarickal V Dileep
- Department of Biotechnology and Microbiology, Kannur University, Thalassery Campus, Palayad, Kerala, India
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Torres MCM, das Chagas L Pinto F, Braz-Filho R, Silveira ER, Pessoa ODL, Jorge RJB, Ximenes RM, Monteiro HSA, Monteiro Evangelista JSA, Diz-Filho EBS, Toyama MH. Antiophidic solanidane steroidal alkaloids from Solanum campaniforme. JOURNAL OF NATURAL PRODUCTS 2011; 74:2168-2173. [PMID: 21962208 DOI: 10.1021/np200479a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Three new solanidane alkaloids bearing a 22,23-epoxy ring (1-3) and four known compounds were isolated from leaves of Solanum campaniforme. The structures were determined using spectroscopic techniques, including 1D and 2D NMR, and HRESIMS experiments. The antiophidic activity of the alkaloids was tested against Bothrops pauloensis venom. Compounds 1-3 completely inhibited myotoxicity without inhibiting phospholipase A2 activity of the venom, while hemorrhage and skin necrosis were significantly reduced in the presence of alkaloids 1 and 2.
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Affiliation(s)
- Maria Conceição M Torres
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, 12.200, Fortaleza-CE, 60.021-970, Brazil
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Shimabuku PS, Fernandes CAH, Magro AJ, Costa TR, Soares AM, Fontes MRM. Crystallization and preliminary X-ray diffraction analysis of a Lys49-phospholipase A2 complexed with caffeic acid, a molecule with inhibitory properties against snake venoms. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:249-52. [PMID: 21301098 DOI: 10.1107/s1744309110051407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 12/07/2010] [Indexed: 11/10/2022]
Abstract
Phospholipases A(2) (PLA(2)s) are one of the main components of bothropic venoms; in addition to their phospholipid hydrolysis action, they are involved in a wide spectrum of pharmacological activities, including neurotoxicity, myotoxicity and cardiotoxicity. Caffeic acid is an inhibitor that is present in several plants and is employed for the treatment of ophidian envenomations in the folk medicine of many developing countries; as bothropic snake bites are not efficiently neutralized by conventional serum therapy, it may be useful as an antivenom. In this work, the cocrystallization and preliminary X-ray diffraction analysis of the Lys49-PLA(2) piratoxin I from Bothrops pirajai venom in the presence of the inhibitor caffeic acid (CA) are reported. The crystals diffracted X-rays to 1.65 Å resolution and the structure was solved by molecular-replacement techniques. The electron-density map unambiguously indicated the presence of three CA molecules that interact with the C-terminus of the protein. This is the first time a ligand has been observed bound to this region and is in agreement with various experiments previously reported in the literature.
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Affiliation(s)
- Patrícia S Shimabuku
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP-Universidade Estadual Paulista, Botucatu-SP, Brazil
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Delatorre P, Rocha BAM, Santi-Gadelha T, Gadelha CAA, Toyama MH, Cavada BS. Crystal structure of Bn IV in complex with myristic acid: a Lys49 myotoxic phospholipase A₂ from Bothrops neuwiedi venom. Biochimie 2010; 93:513-8. [PMID: 21108987 DOI: 10.1016/j.biochi.2010.11.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 11/16/2010] [Indexed: 11/18/2022]
Abstract
The LYS49-PLA₂s myotoxins have attracted attention as models for the induction of myonecrosis by a catalytically independent mechanism of action. Structural studies and biological activities have demonstrated that the myotoxic activity of LYS49-PLA₂ is independent of the catalytic activity site. The myotoxic effect is conventionally thought to be to due to the C-terminal region 111-121, which plays an effective role in membrane damage. In the present study, Bn IV LYS49-PLA₂ was isolated from Bothrops neuwiedi snake venom in complex with myristic acid (CH₃(CH₂)₁₂COOH) and its overall structure was refined at 2.2 Å resolution. The Bn IV crystals belong to monoclinic space group P2₁ and contain a dimer in the asymmetric unit. The unit cell parameters are a = 38.8, b = 70.4, c = 44.0 Å. The biological assembly is a "conventional dimer" and the results confirm that dimer formation is not relevant to the myotoxic activity. Electron density map analysis of the Bn IV structure shows clearly the presence of myristic acid in catalytic site. The relevant structural features for myotoxic activity are located in the C-terminal region and the Bn IV C-terminal residues NKKYRY are a probable heparin binding domain. These findings indicate that the mechanism of interaction between Bn IV and muscle cell membranes is through some kind of cell signal transduction mediated by heparin complexes.
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Affiliation(s)
- P Delatorre
- Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.
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