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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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2
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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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3
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Trento MVC, Sales TA, de Abreu TS, Braga MA, Cesar PHS, Marques TR, Marcussi S. Exploring the structural and functional aspects of the phospholipase A 2 from Naja spp. Int J Biol Macromol 2019; 140:49-58. [PMID: 31421173 DOI: 10.1016/j.ijbiomac.2019.08.125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 01/22/2023]
Abstract
Naja spp. venom is a natural source of active compounds with therapeutic application potential. Phospholipase A2 (PLA2) is abundant in the venom of Naja spp. and can perform neurotoxicity, cytotoxicity, cardiotoxicity, and hematological disorders. The PLA2s from Naja spp. venoms are Asp 49 isoenzymes with the exception of PLA2 Cys 49 from Naja sagittifera. When looking at the functional aspects, the neurotoxicity occurs by PLA2 called β-toxins that have affinity for phosphatidylcholine in nerve endings and synaptosomes membranes, and by α-toxins that block the nicotinic acetylcholine receptors in the neuromuscular junctions. In addition, these neurotoxins may inhibit K+ and Ca++ channels or even interfere with the Na+/K+/ATPase enzyme. The disturbance in the membrane fluidity also results in inhibition of the release of acetylcholine. The PLA2 can act as anticoagulants or procoagulant. The cytotoxicity exerted by PLA2s result from changes in the cardiomyocyte membranes, triggering cardiac failure and hemolysis. The antibacterial activity, however, is the result of alterations that decrease the stability of the lipid bilayer. Thus, the understanding of the structural and functional aspects of PLA2s can contribute to studies on the toxic and therapeutic mechanisms involved in the envenomation by Naja spp. and in the treatment of pathologies.
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Affiliation(s)
- Marcus Vinícius Cardoso Trento
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil.
| | - Thais Aparecida Sales
- Computational Chemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
| | - Tatiane Silva de Abreu
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
| | - Mariana Aparecida Braga
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
| | - Pedro Henrique Souza Cesar
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
| | - Tamara Rezende Marques
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
| | - Silvana Marcussi
- Biochemistry Laboratory, Department of Chemistry, Universidade Federal de Lavras (UFLA), Lavras, Minas Gerais 37200-000, Brazil
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4
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Möller C, Davis WC, Clark E, DeCaprio A, Marí F. Conodipine-P1-3, the First Phospholipases A 2 Characterized from Injected Cone Snail Venom. Mol Cell Proteomics 2019; 18:876-891. [PMID: 30765458 DOI: 10.1074/mcp.ra118.000972] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 02/06/2019] [Indexed: 12/30/2022] Open
Abstract
The phospholipase A2 (PLA2s) superfamily are ubiquitous small enzymes that catalyze the hydrolysis of phospholipids at the sn-2 ester bond. PLA2s in the venom of cone snails (conodipines, Cdpi) are composed of two chains termed as alpha and beta subunits. Conodipines are categorized within the group IX of PLA2s. Here we describe the purification and biochemical characterization of three conodipines (Cdpi-P1, -P2 and -P3) isolated from the injected venom of Conus purpurascens Using proteomics methods, we determined the full sequences of all three conodipines. Conodipine-P1-3 have conserved consensus catalytic domain residues, including the Asp/His dyad. Additionally, these enzymes are expressed as a mixture of proline hydroxylated isoforms. The activities of the native Conodipine-Ps were evaluated by conventional colorimetric and by MS-based methods, which provide the first detailed cone snail venom conodipine activity monitored by mass spectrometry. Conodipines can have medicinal applications such inhibition of cancer proliferation, bacterial and viral infections among others.
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Affiliation(s)
- Carolina Möller
- From the ‡Marine Biochemical Sciences, Chemical Sciences Division, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, South Carolina, 29412
| | - W Clay Davis
- From the ‡Marine Biochemical Sciences, Chemical Sciences Division, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, South Carolina, 29412
| | - Evan Clark
- §Department of Biomedical Sciences, Florida Atlantic University, Boca Raton, Florida, 33431
| | - Anthony DeCaprio
- ¶Department of Chemistry and Biochemistry, Florida International University, SW 8th St, Miami, Florida, 33119
| | - Frank Marí
- From the ‡Marine Biochemical Sciences, Chemical Sciences Division, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, South Carolina, 29412;.
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5
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Melo LL, Mendes MM, Alves LM, Isabel TF, Vieira SA, Gimenes SN, Soares AM, Rodrigues VM, Izidoro LF. Cross-reactivity and inhibition myotoxic effects induced by Bothrops snake venoms using specific polyclonal anti -BnSP7 antibodies. Biologicals 2017; 50:109-116. [DOI: 10.1016/j.biologicals.2017.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 07/31/2017] [Accepted: 08/05/2017] [Indexed: 11/29/2022] Open
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6
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Melaré R, Floriano RS, Gracia M, Rodrigues-Simioni L, Cruz-Höfling MAD, Rocha T. Ultrastructural aspects of mouse nerve-muscle preparation exposed to Bothrops jararacussu and Bothrops bilineatus venoms and their toxins BthTX-I and Bbil-TX: Unknown myotoxic effects. Microsc Res Tech 2016; 79:1082-1089. [PMID: 27535875 DOI: 10.1002/jemt.22748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 07/18/2016] [Accepted: 08/02/2016] [Indexed: 11/10/2022]
Abstract
Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve-muscle preparations exposed to Bothrops venoms and their phospholipase A2 toxins (PLA2 ) can exhibit a neurotoxic pattern as increase in frequency of miniature end-plate potentials (MEPPs) as well as in amplitude of end-plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA2 toxins (BthTX-I and Bbil-TX) in mouse isolated nerve-phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX-I and Bbil-TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic-like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration.
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Affiliation(s)
- Rodolfo Melaré
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil
| | - Rafael Stuani Floriano
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, Zip Code 13083-887, Campinas, SP, Brazil
| | - Marta Gracia
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil
| | - Léa Rodrigues-Simioni
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, Zip Code 13083-887, Campinas, SP, Brazil
| | - Maria Alice da Cruz-Höfling
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Zip Code 13083-862, Campinas, SP, Brazil
| | - Thalita Rocha
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil. .,Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Zip Code 13083-862, Campinas, SP, Brazil.
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7
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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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8
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Bustillo S, García-Denegri ME, Gay C, Van de Velde AC, Acosta O, Angulo Y, Lomonte B, Gutiérrez JM, Leiva L. Phospholipase A(2) enhances the endothelial cell detachment effect of a snake venom metalloproteinase in the absence of catalysis. Chem Biol Interact 2015; 240:30-6. [PMID: 26279213 DOI: 10.1016/j.cbi.2015.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/01/2015] [Accepted: 08/07/2015] [Indexed: 11/18/2022]
Abstract
Microvessel disruption leading to hemorrhage stands among the most dangerous consequences of envenomings by snakes of the family Viperidae. A PIII metalloproteinase (SVMP), balteragin, purified from the venom of the snake Bothrops alternatus, displays a potent hemorrhagic effect, and a moderate myotoxicity in vivo. Previous studies described the ability of this SVMP to induce the detachment of C2C12 myoblasts in culture, without causing cytolysis. Surprisingly, a purified acidic phospholipase A2 (PLA2) from the same venom was found to increase this detaching activity of the SVMP on myoblasts. Since endothelial cells are a natural target of SVMPs in vivo, the possibility that this synergistic effect is also observed on this cell type was explored in the present work. In addition, a first approach of the mechanism of action of this effect was studied. Results clearly confirm that the acidic PLA2, despite lacking toxicity towards endothelial cells, significantly enhances the detaching effect of the SVMP even at a concentration as low as 1 μg/mL. Inhibition of enzymatic activity of the PLA2 by chemical modification with p-bromophenacyl bromide did not affect the synergistic activity, suggesting that this effect is not dependent on phospholipase enzymatic activity and may instead be the consequence of an interaction of the PLA2 with endothelial cell plasma membrane. To our knowledge, this is the first report of a synergistic action of a non toxic PLA2 in enhancing the detachment of endothelial cells induced by a metalloproteinase.
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Affiliation(s)
- Soledad Bustillo
- Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina.
| | | | - Carolina Gay
- Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina
| | | | - Ofelia Acosta
- Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina
| | - Yamileth Angulo
- 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
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Laura Leiva
- Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina
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9
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Reeks TA, Fry BG, Alewood PF. Privileged frameworks from snake venom. Cell Mol Life Sci 2015; 72:1939-58. [PMID: 25693678 PMCID: PMC11113608 DOI: 10.1007/s00018-015-1844-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 11/25/2022]
Abstract
Venom as a form of chemical prey capture is a key innovation that has underpinned the explosive radiation of the advanced snakes (Caenophidia). Small venom proteins are often rich in disulfide bonds thus facilitating stable molecular scaffolds that present key functional residues on the protein surface. New toxin types are initially developed through the venom gland over-expression of normal body proteins, their subsequent gene duplication and diversification that leads to neofunctionalisation as random mutations modify their structure and function. This process has led to preferentially selected (privileged) cysteine-rich scaffolds that enable the snake to build arrays of toxins many of which may lead to therapeutic products and research tools. This review focuses on cysteine-rich small proteins and peptides found in snake venoms spanning natriuretic peptides to phospholipase enzymes, while highlighting their three-dimensional structures and biological functions as well as their potential as therapeutic agents or research tools.
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Affiliation(s)
- T. A. Reeks
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - B. G. Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072 Australia
| | - P. F. Alewood
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
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10
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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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11
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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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12
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Fernández J, Caccin P, Koster G, Lomonte B, Gutiérrez JM, Montecucco C, Postle AD. Muscle phospholipid hydrolysis byBothrops asperAsp49 and Lys49 phospholipase A2myotoxins - distinct mechanisms of action. FEBS J 2013; 280:3878-86. [DOI: 10.1111/febs.12386] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/06/2013] [Accepted: 06/10/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Julián Fernández
- Department of Biomedical Sciences and National Research Council Institute of Neuroscience; University of Padova; Italy
| | - Paola Caccin
- Department of Biomedical Sciences and National Research Council Institute of Neuroscience; University of Padova; Italy
| | - Grielof Koster
- National Institute for Health Research Respiratory Medicine Biomedical Research Unit; University Hospitals Southampton; UK
| | - Bruno Lomonte
- Instituto Clodomiro Picado; Facultad de Microbiología; Universidad de Costa Rica; Costa Rica
| | - José M. Gutiérrez
- Instituto Clodomiro Picado; Facultad de Microbiología; Universidad de Costa Rica; Costa Rica
| | - Cesare Montecucco
- Department of Biomedical Sciences and National Research Council Institute of Neuroscience; University of Padova; Italy
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13
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Huancahuire-Vega S, Corrêa DHA, Hollanda LM, Lancellotti M, Ramos CHI, Ponce-Soto LA, Marangoni S. Chemical modifications of PhTX-I myotoxin from Porthidium hyoprora snake venom: effects on structural, enzymatic, and pharmacological properties. BIOMED RESEARCH INTERNATIONAL 2012; 2013:103494. [PMID: 23484072 PMCID: PMC3591178 DOI: 10.1155/2013/103494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 10/31/2012] [Indexed: 12/03/2022]
Abstract
We recently described the isolation of a basic PLA2 (PhTX-I) from Porthidium hyoprora snake venom. This toxin exhibits high catalytic activity, induces in vivo myotoxicity, moderates footpad edema, and causes in vitro neuromuscular blockade. Here, we describe the chemical modifications of specific amino acid residues (His, Tyr, Lys, and Trp), performed in PhTX-I, to study their effects on the structural, enzymatic, and pharmacological properties of this myotoxin. After chemical treatment, a single His, 4 Tyr, 7 Lys, and one Trp residues were modified. The secondary structure of the protein remained unchanged as measured by circular dichroism; however other results indicated the critical role played by Lys and Tyr residues in myotoxic, neurotoxic activities and mainly in the cytotoxicity displayed by PhTX-I. His residue and therefore catalytic activity of PhTX-I are relevant for edematogenic, neurotoxic, and myotoxic effects, but not for its cytotoxic activity. This dissociation observed between enzymatic activity and some pharmacological effects suggests that other molecular regions distinct from the catalytic site may also play a role in the toxic activities exerted by this myotoxin. Our observations supported the hypothesis that both the catalytic sites as the hypothetical pharmacological sites are relevant to the pharmacological profile of PhTX-I.
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Affiliation(s)
- Salomón Huancahuire-Vega
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil
| | - Daniel H. A. Corrêa
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Luciana M. Hollanda
- Biotechnology Laboratory (LABIOTEC), Department of Biochemistry, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Marcelo Lancellotti
- Biotechnology Laboratory (LABIOTEC), Department of Biochemistry, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Carlos H. I. Ramos
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), Campinas, SP, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, RJ, Brazil
| | - Luis Alberto Ponce-Soto
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil
| | - Sergio Marangoni
- Department of Biochemistry, Institute of Biology, State University of Campinas (UNICAMP), P.O. Box 6109, 13083-970 Campinas, SP, Brazil
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Lomonte B, Rangel J. Snake venom Lys49 myotoxins: From phospholipases A2 to non-enzymatic membrane disruptors. Toxicon 2012; 60:520-30. [DOI: 10.1016/j.toxicon.2012.02.007] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
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15
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Georgieva D, Coronado M, Oberthür D, Buck F, Duhalov D, Arni RK, Betzel C. Crystal structure of a dimeric Ser49 PLA2-like myotoxic component of the Vipera ammodytes meridionalis venomics reveals determinants of myotoxicity and membrane damaging activity. MOLECULAR BIOSYSTEMS 2012; 8:1405-11. [DOI: 10.1039/c2mb05490f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Comparison between apo and complexed structures of bothropstoxin-I reveals the role of Lys122 and Ca2+-binding loop region for the catalytically inactive Lys49-PLA2s. J Struct Biol 2010; 171:31-43. [DOI: 10.1016/j.jsb.2010.03.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 02/23/2010] [Accepted: 03/31/2010] [Indexed: 11/22/2022]
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17
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Understanding the in vitro neuromuscular activity of snake venom Lys49 phospholipase A2 homologues. Toxicon 2010; 55:1-11. [DOI: 10.1016/j.toxicon.2009.10.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 07/22/2009] [Accepted: 10/01/2009] [Indexed: 11/24/2022]
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18
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Romero-Vargas FF, Ponce-Soto LA, Martins-de-Souza D, Marangoni S. Biological and biochemical characterization of two new PLA2 isoforms Cdc-9 and Cdc-10 from Crotalus durissus cumanensis snake venom. Comp Biochem Physiol C Toxicol Pharmacol 2010; 151:66-74. [PMID: 19747981 DOI: 10.1016/j.cbpc.2009.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 08/26/2009] [Accepted: 08/27/2009] [Indexed: 10/20/2022]
Abstract
This work reports the purification, biological characterization and amino acid sequence of two new basic PLA(2) isoforms, Cdc-9 and Cdc-10, purified from the Crotalus durissus cumanensis venom by one step analytical chromatography reverse phase HPLC. The molecular masses of the PLA(2) were 14,175+/-2.7 Da for Cdc-9 and 14,228+/-3.5 Da for Cdc-10 both deduced by primary structure and confirmed by MALDI-TOF. The isoforms presented an amino acid sequence of 122 amino acid residues, being Cdc-9: SLVQFNKMIK FETRKSGLPF YAAYGCYCGW GGQRPKDATD RCCFVHDCCY GKVAKCNTKW DIYSYSLKSG YITCGKGTWC KEQICECDRV AAECLRRSLS TYKNEYMFYP DSRCREPPEY TC with pI value of 8.25 and Cdc-10: SLLQFNKMIK FETRKSGVPF YAAYGCYCGW GGRRPKDPTD RCCFVHDCCY GKLTKCNTKW DIYSYSLKSG YITCGKGTWC KEQICECDRV AAECLRRSLN TYKNEYMFYP DSRCRGPPEY TC with a pI value of 8.46, showing highly conserved Ca(2+)-binding and catalytic sites. The PLA(2) activity decreased when the isoforms Cdc-9 and Cdc-10 were incubated with 4-bromophenacyl bromide (p-BPB), anhydrous acetic acid and p-nitrobenzene sulfonyl fluoride (NBSF) when compared with the activity of both native isoforms. In mice, the PLA(2) isoforms Cdc-9 and Cdc-10 induced myonecrosis and edema. Myotoxic and edema activities were reduced after treatment of the isoforms with p-BPB; acetylation of the lysine residues and the treatment of PLA(2) with NBSF have also induced edema reduction. However, p-BPB strongly diminishes the local and systemic myotoxic effects.
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19
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The interaction of bothropstoxin-I (Lys49-PLA2) with liposome membranes. Toxicon 2009; 54:525-30. [DOI: 10.1016/j.toxicon.2009.05.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/23/2009] [Accepted: 05/26/2009] [Indexed: 11/23/2022]
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20
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dos Santos JI, Soares AM, Fontes MR. Comparative structural studies on Lys49-phospholipases A2 from Bothrops genus reveal their myotoxic site. J Struct Biol 2009; 167:106-16. [DOI: 10.1016/j.jsb.2009.04.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 03/26/2009] [Accepted: 04/17/2009] [Indexed: 11/25/2022]
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21
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Santos-Filho NA, Silveira LB, Oliveira CZ, Bernardes CP, Menaldo DL, Fuly AL, Arantes EC, Sampaio SV, Mamede CC, Beletti ME, de Oliveira F, Soares AM. A new acidic myotoxic, anti-platelet and prostaglandin I2 inductor phospholipase A2 isolated from Bothrops moojeni snake venom. Toxicon 2008; 52:908-17. [DOI: 10.1016/j.toxicon.2008.08.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 08/07/2008] [Accepted: 08/08/2008] [Indexed: 10/21/2022]
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22
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Abstract
Phospholipase A(2) (PLA(2)), a common toxic component of snake venom, has been implicated in various pharmacological effects. Ecarpholin S, isolated from the venom of the snake Echis carinatus sochureki, is a phospholipase A(2) (PLA(2)) belonging to the Ser(49)-PLA(2) subgroup. It has been characterized as having low enzymatic but potent myotoxic activities. The crystal structures of native ecarpholin S and its complexes with lauric acid, and its inhibitor suramin, were elucidated. This is the first report of the structure of a member of the Ser(49)-PLA(2) subgroup. We also examined interactions of ecarpholin S with phosphatidylglycerol and lauric acid, using surface plasmon resonance, and of suramin with isothermal titration calorimetry. Most Ca(2+)-dependent PLA(2) enzymes have Asp in position 49, which plays a crucial role in Ca(2+) binding. The three-dimensional structure of ecarpholin S reveals a unique conformation of the Ca(2+)-binding loop that is not favorable for Ca(2+) coordination. Furthermore, the endogenously bound fatty acid (lauric acid) in the hydrophobic channel may also interrupt the catalytic cycle. These two observations may account for the low enzymatic activity of ecarpholin S, despite full retention of the catalytic machinery. These observations may also be applicable to other non-Asp(49)-PLA(2) enzymes. The interaction of suramin in its complex with ecarpholin S is quite different from that reported for the Lys(49)-PLA(2)/suramin complex(,) where the interfacial recognition face (i-face), C-terminal region, and N-terminal region of ecarpholin S play important roles. This study provides significant structural and functional insights into the myotoxic activity of ecarpholin S and, in general, of non-Asp(49)-PLA(2) enzymes.
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23
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Corrêa LC, Marchi-Salvador DP, Cintra AC, Sampaio SV, Soares AM, Fontes MR. Crystal structure of a myotoxic Asp49-phospholipase A2 with low catalytic activity: Insights into Ca2+-independent catalytic mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:591-9. [DOI: 10.1016/j.bbapap.2008.01.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2007] [Revised: 12/05/2007] [Accepted: 01/03/2008] [Indexed: 11/16/2022]
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25
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Stábeli RG, Amui SF, Sant'Ana CD, Pires MG, Nomizo A, Monteiro MC, Romão PRT, Guerra-Sá R, Vieira CA, Giglio JR, Fontes MRM, Soares AM. Bothrops moojeni myotoxin-II, a Lys49-phospholipase A2 homologue: an example of function versatility of snake venom proteins. Comp Biochem Physiol C Toxicol Pharmacol 2006; 142:371-381. [PMID: 16442348 DOI: 10.1016/j.cbpc.2005.11.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 11/22/2005] [Accepted: 11/23/2005] [Indexed: 10/25/2022]
Abstract
MjTX-II, a myotoxic phospholipase A(2) (PLA(2)) homologue from Bothrops moojeni venom, was functionally and structurally characterized. The MjTX-II characterization included: (i) functional characterization (antitumoral, antimicrobial and antiparasitic effects); (ii) effects of structural modifications by 4-bromophenacyl bromide (BPB), cyanogen bromide (CNBr), acetic anhydride and 2-nitrobenzenesulphonyl fluoride (NBSF); (iii) enzymatic characterization: inhibition by low molecular weight heparin and EDTA; and (iv) molecular characterization: cDNA sequence and molecular structure prediction. The results demonstrated that MjTX-II displayed antimicrobial activity by growth inhibition against Escherichia coli and Candida albicans, antitumoral activity against Erlich ascitic tumor (EAT), human breast adenocarcinoma (SK-BR-3) and human T leukemia cells (JURKAT) and antiparasitic effects against Schistosoma mansoni and Leishmania spp., which makes MjTX-II a promising molecular model for future therapeutic applications, as well as other multifunctional homologous Lys49-PLA(2)s or even derived peptides. This work provides useful insights into the structural determinants of the action of Lys49-PLA(2) homologues and, together with additional strategies, supports the concept of the presence of others "bioactive sites" distinct from the catalytic site in snake venom myotoxic PLA(2)s.
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Affiliation(s)
- Rodrigo G Stábeli
- Instituto de Pesquisas em Patologias Tropicais, IPEPATRO, Universidade Federal de Rondonia, UNIR-RO, Brazil
| | - Saulo F Amui
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto-SP, Brazil
| | - Carolina D Sant'Ana
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto-SP, Brazil
| | - Matheus G Pires
- Instituto de Pesquisas em Patologias Tropicais, IPEPATRO, Universidade Federal de Rondonia, UNIR-RO, Brazil
| | - Auro Nomizo
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto-SP, Brazil
| | - Marta C Monteiro
- Universidade Estadual do Centro-Oeste/UNICENTRO, Guarapuava-PR, Brazil
| | - Pedro R T Romão
- Laboratório de Imunoparasitologia, UNISUL, Tubarão-SC, Brazil
| | - Renata Guerra-Sá
- Laboratório de Bioquímica e Biologia Molecular-Departamento de Ciências Biológicas, UFOP, Ouro Preto-MG, Brazil
| | - Carlos A Vieira
- Departamento de Bioquímica e Imunologia, FMRP, USP, Ribeirão Preto-SP, Brazil
| | - José R Giglio
- Departamento de Bioquímica e Imunologia, FMRP, USP, Ribeirão Preto-SP, Brazil
| | | | - Andreimar M Soares
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto-SP, Brazil.
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26
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Wei JF, Wei XL, Chen QY, Huang T, Qiao LY, Wang WY, Xiong YL, He SH. N49 phospholipase A2, a unique subgroup of snake venom group II phospholipase A2. BIOCHIMICA ET BIOPHYSICA ACTA 2006; 1760:462-71. [PMID: 16413680 DOI: 10.1016/j.bbagen.2005.11.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 11/28/2005] [Accepted: 11/29/2005] [Indexed: 02/05/2023]
Abstract
A novel phospholipase A2 (PLA2) with Asn at its site 49 was purified from the snake venom of Protobothrops mucrosquamatus by using SP-Sephadex C25, Superdex 75, Heparin-Sepharose (FF) and HPLC reverse-phage C18 chromatography and designated as TM-N49. It showed a molecular mass of 13.875 kDa on MALDI-TOF. TM-N49 does not possess enzymatic, hemolytic and hemorrhagic activities. It fails to induce platelet aggregation by itself, and does not inhibit the platelet aggregation induced by ADP. However, it exhibits potent myotoxic activity causing inflammatory cell infiltration, severe myoedema, myonecrosis and myolysis in the gastrocnemius muscles of BALB/c mice. Phylogenetic analysis found that that TM-N49 combined with two phospholipase A2s from Trimeresurus stejnegeri, TsR6 and CTs-R6 cluster into one group. Structural and functional analysis indicated that these phospholipase A2s are distinct from the other subgroups (D49 PLA2, S49 PLA2 and K49 PLA2) and represent a unique subgroup of snake venom group II PLA2, named N49 PLA2 subgroup.
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Affiliation(s)
- Ji-Fu Wei
- Allergy and Inflammation Research Institute, the Shantou University Medical College, Shantou, Guangdong, 515031, China
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27
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Ruller R, Aragão EA, Chioato L, Ferreira TL, de Oliveira AHC, Sà JM, Ward RJ. A predominant role for hydrogen bonding in the stability of the homodimer of bothropstoxin-I, A lysine 49-phospholipase A2. Biochimie 2005; 87:993-1003. [PMID: 15967564 DOI: 10.1016/j.biochi.2005.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 04/01/2005] [Accepted: 04/15/2005] [Indexed: 11/17/2022]
Abstract
Bothropstoxin-I (BthTx-I) is a homodimeric Lys49-phospholipase A(2) isolated from Bothrops jararacussu venom which damages liposome membranes via a Ca(2+)-independent mechanism. The Glu12/Trp77/Lys80 triad at the dimer interface forms extensive intermolecular hydrogen bonds and hydrophobic contacts, and equilibrium chemical denaturation was used to evaluate the effect on homodimer stability of site-directed mutagenesis of these residues. Changes in the intrinsic fluorescence anisotropy and farUV circular dichroism signals were analyzed using a two-step unfolding model of the BthTx-I dimer to estimate the Gibbs free energy changes of transitions between the dimer and native monomer and between the native and denatured monomers. Whereas the Trp77His, Trp77Gln and Glu12Gln mutants showed native-like dimer stabilities, the Trp77Phe, Lys80Met and Lys80Gly mutants showed significantly reduced K(d) values. A reduced dimer stability is correlated with a decrease in the Ca(2+)-independent membrane damaging activity as monitored by the release of a liposome entrapped fluorescent marker. Although the membrane damaging activity of the monomer is fivefold less than the dimer, the myotoxic activity was unaffected, indicating that these two effects are not correlated. These data suggest that the BthTx-I dimer is predominantly stabilized by hydrogen bonding interactions, and highlight the importance of the homodimeric form for efficient Ca(2+)-independent membrane damage.
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Affiliation(s)
- R Ruller
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, FMRP-USP, Ribeirão Preto, SP, Brazil
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Angulo Y, Gutiérrez JM, Soares AM, Cho W, Lomonte B. Myotoxic and cytolytic activities of dimeric Lys49 phospholipase A2 homologues are reduced, but not abolished, by a pH-induced dissociation. Toxicon 2005; 46:291-6. [PMID: 15970303 DOI: 10.1016/j.toxicon.2005.03.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 03/30/2005] [Accepted: 03/31/2005] [Indexed: 12/01/2022]
Abstract
Lys49 phospholipase A2 (PLA2) homologues are myotoxic proteins devoid of catalytic activity. Their toxic determinants map to the C-terminal region 115-129, which plays an effector role in membrane damage. The dimeric state was reported to be essential for a Lys49 PLA2 which lost its liposome-disrupting activity after dissociating into monomers at pH 5.0. This study, evaluated the effects of a pH-induced dissociation on the toxicity of four Lys49 PLA2s, using biological targets instead. Both their cytolytic and myotoxic activities were lower at pH 5.0 than at pH 7.2. However, in contrast with experiments using artificial bilayers, toxic effects upon biological targets were not abolished at pH 5.0. Importantly, C-terminal synthetic peptides of two Lys49 PLA2s also showed lower cytolytic action at pH 5.0 than at pH 7.2, indicating that factors other than the dimeric/monomeric state of the proteins may also be involved in these differences of toxicity. Results support the view that the dimeric state of Lys49 PLA2s could play an enhancing, although not essential role, in their C-terminal region-mediated mechanism of myotoxicity.
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Affiliation(s)
- Yamileth Angulo
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica.
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29
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Bao Y, Bu P, Jin L, Hongxia W, Yang Q, An L. Purification, characterization and gene cloning of a novel phospholipase A2 from the venom of Agkistrodon blomhoffii ussurensis. Int J Biochem Cell Biol 2005; 37:558-65. [PMID: 15618013 DOI: 10.1016/j.biocel.2004.05.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 05/13/2004] [Accepted: 05/17/2004] [Indexed: 11/30/2022]
Abstract
A new phospholipase A2 with Gln at the site 49, abbreviated as Gln49-PLA2, has been purified from the venom of Agkistrodon blomhoffii ussurensis by using ion-exchange chromatography, gel filtration chromatography and reversed-phase HPLC, and behaves as a single-band on SDS-PAGE. Its molecular weight is 13881.85+/-0.33 Da given by mass spectrometry and pI is about 8.56 given by isoelectric focusing. Gln49-PLA2 does not show phospholipase A2 and hemorrhagic activity, whereas shows weak toxic and apparent anticoagulant activity. Based on the N-terminal sequencing and peptide mass fingerprint analysis, Gln49-PLA2 cDNA has been cloned by means of RT-PCR. Gln49-PLA2 consists of 122 amino acid residues and has the structural features of class II of snake venom phospholipase A2.
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Affiliation(s)
- Yongming Bao
- Department of Bioscience and Biotechnology, Dalian University of Technology, 2 Linggong Road, Dalian 116024, PR China.
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30
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Núñez V, Castro V, Murillo R, Ponce-Soto LA, Merfort I, Lomonte B. Inhibitory effects of Piper umbellatum and Piper peltatum extracts towards myotoxic phospholipases A2 from Bothrops snake venoms: isolation of 4-nerolidylcatechol as active principle. PHYTOCHEMISTRY 2005; 66:1017-25. [PMID: 15896371 DOI: 10.1016/j.phytochem.2005.03.026] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Revised: 01/27/2005] [Indexed: 05/02/2023]
Abstract
Phospholipases A(2) (PLA(2)) are important constituents of snake venoms, being responsible for several of their toxic actions. Extracts from plants used in folk medicine were screened for inhibition of the enzymatic activity of myotoxin I, a PLA(2) from Bothrops asper. Piper umbellatum and Piper peltatum extracts tested positive, and their fractionation resulted in the isolation of 4-nerolidylcatechol. Its inhibitory effects towards toxic activities of two Bothrops myotoxins, representing catalytically active (Asp49) and catalytically inactive (Lys49) types of group II PLA(2)s, respectively, were characterized. The enzyme activity of B. asper myotoxin I was completely inhibited by 4-nerolidylcatechol at an inhibitor:toxin ratio of 10:1 (wt/wt) with an IC50 of approximately 1mM. In addition, 4-nerolidylcatechol inhibited representatives of groups I and III of PLA(2)s. Its preincubation with Bothrops myotoxins significantly reduced their myotoxic and edema-inducing activities in animal experiments. However, when 4-nerolidylcatechol was administered in situ, immediately after toxin injection, its inhibitory ability was substantially lower or negligible. This might be explained by the rapid action of these toxins in vivo, together with the slow inactivation of PLA(2) activity observed in vitro. Electrophoretic and chromatographic analyses of myotoxins ruled out major changes in protein charge, hydrophobicity, or gross molecular mass being involved in the inhibition mechanism. Mass spectrometry determinations are consistent with the covalent modification of myotoxin by one molecule of 4-nerolidylcatechol. Finally, a novel compound was isolated from both Piper species, sharing the nerolidyl skeleton, but nevertheless not being inhibitory towards the PLA(2)s studied.
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Affiliation(s)
- Vitelbina Núñez
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica, San José, Costa Rica
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31
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Fuly AL, Soares AM, Marcussi S, Giglio JR, Guimarães JA. Signal transduction pathways involved in the platelet aggregation induced by a D-49 phospholipase A2 isolated from Bothrops jararacussu snake venom. Biochimie 2005; 86:731-9. [PMID: 15556284 DOI: 10.1016/j.biochi.2004.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2003] [Revised: 07/01/2004] [Accepted: 07/02/2004] [Indexed: 10/26/2022]
Abstract
Bothropstoxin-II (Bthtx-II), an Asp-49 phospholipase A(2) (D-PLA(2)) isolated from Bothrops jararacussu snake venom is able to induce platelet aggregation in a concentration-dependent manner. This effect was not due to the release of ADP from platelets since the aggregation was not suppressed by ADP scavenger systems. PMSF and PPACK were unable to inhibit Bthtx-II-induced platelet aggregation. Thus, a thrombin-like proaggregating activity of Bthtx-II can be excluded as its mechanism of action. On the other hand, indomethacin at low concentrations inhibited more markedly the ATP-release reaction than the aggregation induced by Bthtx-II, indicating that generation of cyclooxigenase products is not the most important event for the platelet aggregation reaction. It was also found that staurosporine and genistein suppressed both platelet aggregation and ATP-release reactions, but not the platelet shape-change induced by Bthtx-II. Substances that either directly activates adenylyl cyclase enzyme (forskolin and PGE(1)) or cell-permeant increasing agents (dibutyril-cAMP) inhibited in a concentration-dependent fashion, the platelet aggregation effects induced by the protein. It is concluded that Bthtx-II induces platelet aggregation and secretion through multiple signal transduction pathways.
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Affiliation(s)
- André L Fuly
- Departamento de Bioquímica Médica, ICB/CCS, Universidade Federal do Rio de Janeiro, 21941-590 Brazil
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32
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Sá J, Chioato L, Ferreira T, de Oliveira A, Ruller R, Rosa J, Greene L, Ward R. Topology of the substrate-binding site of a Lys49-phospholipase A2 influences Ca2+-independent membrane-damaging activity. Biochem J 2005; 382:191-8. [PMID: 15147240 PMCID: PMC1133930 DOI: 10.1042/bj20031946] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 05/11/2004] [Accepted: 05/17/2004] [Indexed: 11/17/2022]
Abstract
BthTx-I (bothropstoxin-I) is a myotoxic Lys49-PLA2 (phospholipase A2 with Lys49) isolated from Bothrops jararacussu venom, which damages liposome membranes by a Ca2+-independent mechanism. The highly conserved Phe5/Ala102/Phe106 motif in the hydrophobic substrate-binding site of the Asp49-PLA2s is substituted by Leu5/Val102/Leu106 in the Lys49-PLA2s. The Leu5/Val102/Leu106 triad in BthTx-I was sequentially mutated via all single- and double-mutant combinations to the Phe5/Ala102/Phe106 mutant. All mutants were expressed as inclusion bodies in Escherichia coli, and the thermal stability (Tm), together with the myotoxic and Ca2+-independent membrane-damaging activities of the recombinant proteins, were evaluated. The far-UV CD profiles of the native, wild-type recombinant and the L106F (Leu106-->Phe) and L5F/F102A/L106F mutant proteins were identical. The L5F, V102A, L5F/V102A and V102A/L106F mutants showed distorted far-UV CD profiles; however, only the L5F and L5F/V102A mutants showed significant decreases in Tm. Alterations in the far-UV CD spectra correlated with decreased myotoxicity and protein-induced release of a liposome-entrapped marker. However, the V102A/L106F and L5F/V102A/L106F mutants, which presented high myotoxic activities, showed significantly reduced membrane-damaging activity. This demonstrates that the topology of the substrate-binding region of BthTx-I has a direct effect on the Ca2+-independent membrane damage, and implies that substrate binding retains an important role in this process.
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Affiliation(s)
- Juliana Martha Sá
- *Departamento de Bioquímica e Immunologia, FMRP-USP, Ribeirão Preto-SP, Brazil
| | - Lucimara Chioato
- *Departamento de Bioquímica e Immunologia, FMRP-USP, Ribeirão Preto-SP, Brazil
| | - Tatiana Lopes Ferreira
- †Departamento de Química, FFCLRP-USP, Avenida Bandeirantes 3900, CEP 14049-901, Ribeirão Preto-SP, Brazil
| | - Arthur H. C. de Oliveira
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Roberto Ruller
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - José César Rosa
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
- §Centro de Química de Proteínas, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Lewis J. Greene
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
- §Centro de Química de Proteínas, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Richard J. Ward
- †Departamento de Química, FFCLRP-USP, Avenida Bandeirantes 3900, CEP 14049-901, Ribeirão Preto-SP, Brazil
- To whom correspondence should be addressed (email )
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Ambrosio ALB, Nonato MC, de Araújo HSS, Arni R, Ward RJ, Ownby CL, de Souza DHF, Garratt RC. A Molecular Mechanism for Lys49-Phospholipase A2 Activity Based on Ligand-induced Conformational Change. J Biol Chem 2005; 280:7326-35. [PMID: 15596433 DOI: 10.1074/jbc.m410588200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, obtained under different crystallization conditions. The three forms present notable structural differences and reveal that the presence of a ligand in the active site (naturally presumed to be a fatty acid) induces the exposure of a hydrophobic surface (the hydrophobic knuckle) toward the C terminus. The knuckle in A. contortrix laticinctus myotoxin involves the side chains of Phe(121) and Phe(124) and is a consequence of the formation of a canonical structure for the main chain within the region of residues 118-125. Comparison with other Lys(49)-phospholipase A(2) myotoxins shows that although the knuckle is a generic structural motif common to all members of the family, it is not readily recognizable by simple sequence analyses. An activation mechanism is proposed that relates fatty acid retention at the active site to conformational changes within the C-terminal region, a part of the molecule that has long been associated with Ca(2+)-independent membrane damaging activity and myotoxicity. This provides, for the first time, a direct structural connection between the phospholipase "active site" and the C-terminal "myotoxic site," justifying the otherwise enigmatic conservation of the residues of the former in supposedly catalytically inactive molecules.
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Affiliation(s)
- Andre L B Ambrosio
- Centro de Biotecnologia Molecular Estrutural, Instituto de Física de São Carlos, USP, São Carlos-SP CEP 13560-970, Brazil
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Watanabe L, Soares AM, Ward RJ, Fontes MRM, Arni RK. Structural insights for fatty acid binding in a Lys49-phospholipase A2: crystal structure of myotoxin II from Bothrops moojeni complexed with stearic acid. Biochimie 2005; 87:161-7. [PMID: 15760708 DOI: 10.1016/j.biochi.2004.11.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 11/15/2004] [Indexed: 11/25/2022]
Abstract
The crystal structure of dimeric Lys49-phospholipase A2 myotoxin-II from Bothrops moojeni (MjTX-II) co-crystallized with stearic acid (C(18)H(36)O(2)) has been determined at a resolution of 1.8 A. The electron density maps permitted the unambiguous inclusion of six stearic acid molecules in the refinement. Two stearic acid molecules could be located in the substrate-binding cleft of each monomer in positions, which favor the interaction of their carboxyl groups with active site residues. The way of binding of stearic acids to this Lys49-PLA(2)s is analogous to phospholipids and transition state analogues to catalytically active PLA(2)s. Two additional stearic acid molecules were located at the dimer interface region, defining a hitherto unidentified acyl-binding site on the protein surface. The strictly conserved Lys122 for Lys49-PLA(2)s may play a fundamental role for stabilization of legend-protein complex. The comparison of MjTX-II/satiric acid complex with other Lys-PLA(2)s structures whose putative fatty acids were located at their active site is also analysed. Molecular details of the stearic acid/protein interactions provide insights to binding in group I/II PLA(2)s, and to the possible interactions of Lys49-PLA(2)s with target membranes.
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Affiliation(s)
- Leandra Watanabe
- Departamento de Física, IBILCE, UNESP, S. J. do Rio Preto-SP, Brazil
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35
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Toyama MH, Toyama DO, Joazeiro PP, Carneiro EM, Beriam LOS, Marangoni LS, Boschero AC. Biological and Structural Characterization of a New PLA2 from the Crotalus durissus collilineatus Venom. Protein J 2005; 24:103-12. [PMID: 16003952 DOI: 10.1007/s10930-004-1517-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the present article we report on the biological characterization and amino acid sequence of a new basic Phospholipases A2 (PLA2) isolated from the Crotalus durissus collilineatus venom (Cdcolli F6), which showed the presence of 122 amino acid residues with a pI value of 8.3, molecular mass of 14 kDa and revealed an amino acid sequence identity of 80% with crotalic PLA2s such as Mojave B, Cdt F15, and CROATOX. This homology, however, dropped to 50% if compared to other sources of PLA2s such as from the Bothrops snake venom. Also, this PLA2 induced myonecrosis, although this effect was lower than that of BthTx-I or whole crotoxin and it was able to induce a strong blockage effect on the chick biventer neuromuscular preparation, independently of the presence of the acid subunid (crotapotin). The neurotoxic effect was strongly reduced by pre-incubation with heparin or with anhydrous acetic acid and p-BPB showed a similar reduction. The p-BPB did not reduce significantly the myotoxic activity induced by the PLA2, but the anhydrous acetic acid treatment and the pre-incubation of PLA2 with heparin reduced significantly its effects. This protein showed a strong antimicrobial activity against Xanthomonas axonopodis passiforae (Gram-negative), which was drastically reduced by incubation of this PLA2 with p-BPB, but this effect was marginally reduced after treatment with anhydrous acetic acid. Our findings here allow to speculate that basic amino acid residues on the C-terminal and molecular regions near catalytic site regions such as Calcium binding loop or beta-wing region may be involved in the binding of this PLA2 to the molecular receptor to induce the neurotoxic effect. The bactericidal effect, however, was completely dependent on the enzymatic activity of this protein.
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Affiliation(s)
- M H Toyama
- UNESP, Campus do Litoral Paulista, Unidade de São Vicente.
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36
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Magro AJ, Murakami MT, Marcussi S, Soares AM, Arni RK, Fontes MRM. Crystal structure of an acidic platelet aggregation inhibitor and hypotensive phospholipase A2 in the monomeric and dimeric states: insights into its oligomeric state. Biochem Biophys Res Commun 2004; 323:24-31. [PMID: 15351695 DOI: 10.1016/j.bbrc.2004.08.046] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2004] [Indexed: 11/18/2022]
Abstract
Phospholipases A2 belong to the superfamily of proteins which hydrolyzes the sn-2 acyl groups of membrane phospholipids to release arachidonic acid and lysophospholipids. An acidic phospholipase A2 isolated from Bothrops jararacussu snake venom presents a high catalytic, platelet aggregation inhibition and hypotensive activities. This protein was crystallized in two oligomeric states: monomeric and dimeric. The crystal structures were solved at 1.79 and 1.90 angstroms resolution, respectively, for the two states. It was identified a Na+ ion at the center of Ca2+-binding site of the monomeric form. A novel dimeric conformation with the active sites exposed to the solvent was observed. Conformational states of the molecule may be due to the physicochemical conditions used in the crystallization experiments. We suggest dimeric state is one found in vivo.
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Affiliation(s)
- Angelo J Magro
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP, Botucatu-SP, Brazil
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37
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Cecchini AL, Soares AM, Cecchini R, de Oliveira AHC, Ward RJ, Giglio JR, Arantes EC. Effect of crotapotin on the biological activity of Asp49 and Lys49 phospholipases A(2) from Bothrops snake venoms. Comp Biochem Physiol C Toxicol Pharmacol 2004; 138:429-36. [PMID: 15536050 DOI: 10.1016/j.cca.2004.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Revised: 07/07/2004] [Accepted: 07/14/2004] [Indexed: 11/25/2022]
Abstract
Myonecrosis, in addition to edema and other biological manifestations, are conspicuous effects of Bothrops snake venoms, some of them caused by phospholipases A(2) (PLA(2)s). Asp49-PLA(2)s are catalytically active, whereas Lys49-PLA(2)s, although highly toxic, have little or no enzymatic activity upon artificial substrates, due to a substitution of lysine for aspartic acid at position 49. Crotapotin (CA), the acidic counterpart of crotoxin PLA(2) (CB), is a PLA(2)-like protein from Crotalus durissus terrificus snake venom, and is considered a chaperone protein for CB, able to increase its lethality about ten fold, but to inhibit the formation of the rat paw edema induced by carrageenin and by snake venoms. In this study, we demonstrate that CA significantly inhibits the edema induced by BthTX-I (23% inhibition), BthTX-II (27%), PrTX-I (25%), PrTX-III (35%) and MjTX-II (10%) on the mouse paw. CK levels evoked by isolated Asp49 or Lys49-PLA(2)s were reduced by 40% to 54% in the presence of CA and, in all cases, the membrane damaging activity of the toxins was also reduced. Circular dichroism spectra of the PLA(2)s in the presence and absence of CA showed that there was not any detectable secondary structural modification due to association between CA and the myotoxins. However, Fourier Transformed Infrared (FT-IR) analysis indicated that ionic and hydrophobic contacts contributed to stabilize this interaction.
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Affiliation(s)
- A L Cecchini
- Depto de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Brazil
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38
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Soares AM, Giglio JR. Chemical modifications of phospholipases A2 from snake venoms: effects on catalytic and pharmacological properties. Toxicon 2004; 42:855-68. [PMID: 15019487 DOI: 10.1016/j.toxicon.2003.11.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholipases A2 (PLA2s) constitute major components of snake venoms and have been extensively investigated not only because they are very abundant in these venoms but mainly because they display a wide range of biological effects, including neurotoxic, myotoxic, cytotoxic, edema-inducing, artificial membrane disrupting, anti-coagulant, platelet aggregation inhibiting, hypotensive, bactericidal, anti-HIV, anti-tumoral, anti-malarial and anti-parasitic. Due to this functional diversity, these structurally similar proteins aroused the interest of many researchers as molecular models for study of structure-function relationships. One of the main experimental strategies used for the study of myotoxic PLA2s is the traditional chemical modification of specific amino acid residues (His, Met, Lys, Tyr, Trp and others) and examination of the consequent effects upon the enzymatic, toxic and pharmacological activities. This line of research has provided useful insights into the structural determinants of the action of these enzymes and, together with additional strategies, supports the concept of the presence of 'pharmacological sites' distinct from the catalytic site in snake venom myotoxic PLA2s.
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Affiliation(s)
- Andreimar M Soares
- Departamento de Biotecnologia, Universidade de Ribeirão Preto (UNAERP), Ribeirão Presto, SP, Brazil.
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39
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Ohno M, Chijiwa T, Oda-Ueda N, Ogawa T, Hattori S. Molecular evolution of myotoxic phospholipases A2 from snake venom. Toxicon 2004; 42:841-54. [PMID: 15019486 DOI: 10.1016/j.toxicon.2003.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
After two decades of study, we draw the conclusion that venom-gland phospholipase A2 (PLA2) isozymes, including PLA2 myotoxins of Crotalinae snakes, have evolved in an accelerated manner to acquire their diverse physiological activities. In this review, we describe how accelerated evolution of venom PLA2 isozymes was discovered. This type of evolution is fundamental for other venom isozyme systems. Accelerated evolution of venom PLA2 isozyme genes is due to rapid change in exons, but not in introns and the flanking regions, being completely opposite to the case of the ordinary isozyme genes. The molecular mechanism by which proper base substitutions had occurred in the particular sites of venom isozyme genes is a puzzle to be solved in future studies. It should be noted that accelerated evolution occurred until the isozymes had acquired their particular function and, since then, they have evolved with less frequent mutation, possibly for functional conservation. We also found that interisland mutations occurred in venom PLA2 isozymes. The relationships between mutation and its driving force are speculative and the real mechanism remains a mystery.
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Affiliation(s)
- Motonori Ohno
- Department of Applied Life Science, Faculty of Engineering, Sojo University, Kumamoto 860-0082, Japan.
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40
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Lomonte B, Angulo Y, Calderón L. An overview of lysine-49 phospholipase A2 myotoxins from crotalid snake venoms and their structural determinants of myotoxic action. Toxicon 2003; 42:885-901. [PMID: 15019489 DOI: 10.1016/j.toxicon.2003.11.008] [Citation(s) in RCA: 223] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In 1984, the first venom phospholipase A2 (PLA2) with a lysine substituting for the highly conserved aspartate 49 was discovered, in the North American crotalid snake Agkistrodon p. piscivorus [J. Biol. Chem. 259 (1984) 13839]. Ten years later, the first mapping of a 'toxic region' on a Lys49 PLA2 was reported, in Bothrops asper myotoxin II [J. Biol. Chem. 269 (1994) 29867]. After a further decade of research on the Lys49 PLA2s, a better understanding of their structural determinants of toxicity and mode of action is rapidly emerging, with myotoxic effector sites identified at the C-terminal region in at least four proteins: B. asper myotoxin II, A. p. piscivorus K49 PLA2, A. c. laticinctus ACL myotoxin, and B. jararacussu bothropstoxin I. Although important features still remain to be established, their toxic mode of action has now been understood in its more general concepts, and a consistent working hypothesis can be experimentally supported. It is proposed that all the toxic activities of Lys49 PLA2s are related to their ability to destabilize natural (eukaryotic and prokaryotic) and artificial membranes, using a cationic/hydrophobic effector site located at their C-terminal loop. This review summarizes the general properties of the Lys49 PLA2 myotoxins, emphasizing the development of current concepts and hypotheses concerning the molecular basis of their toxic activities.
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Affiliation(s)
- Bruno Lomonte
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica.
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41
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Murakami MT, Arni RK. A structure based model for liposome disruption and the role of catalytic activity in myotoxic phospholipase A2s. Toxicon 2003; 42:903-13. [PMID: 15019490 DOI: 10.1016/j.toxicon.2003.11.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Venom phospholipase A2s (PLA2s) display a wide spectrum of pharmacological activities and, based on the wealth of biochemical and structural data currently available for PLA2s, mechanistic models can now be inferred to account for some of these activities. A structural model is presented for the role played by the distribution of surface electrostatic potential in the ability of myotoxic D49/K49 PLA2s to disrupt multilamellar vesicles containing negatively charged natural and non-hydrolyzable phospholipids. Structural evidence is provided for the ability of K49 PLA2s to bind phospholipid analogues and for the existence of catalytic activity in K49 PLA2s. The importance of the existence of catalytic activity of D49 and K49 PLA2s in myotoxicity is presented.
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Affiliation(s)
- M T Murakami
- Department of Biophysics, IBILCE/UNESP, R. Cristovão Colombo 2265, CEP 15054-000, São José do Rio Preto-SP, Brazil
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42
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Fuly AL, Calil-Elias S, Martinez AMB, Melo PA, Guimarães JA. Myotoxicity induced by an acidic Asp-49 phospholipase A(2) isolated from Lachesis muta snake venom. Comparison with lysophosphatidylcholine. Int J Biochem Cell Biol 2003; 35:1470-81. [PMID: 12818242 DOI: 10.1016/s1357-2725(03)00129-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In a previous report we showed that Lachesis muta crude venom displays potent indirect hemolytic activity and myotoxicity when injected into mice. Then, a phospholipase A(2) (PLA(2)) (LM-PLA(2)-I) responsible for these activities was isolated. More recently, a catalytically active isoenzyme (LM-PLA(2)-II) with molecular mass of 18 kDa and isoeletric point at pH 5.4 was isolated from the same snake venom. LM-PLA(2)-II inhibited ADP- and collagen-induced platelet aggregation as well as induced a potent paw edema reaction in rats. Here we show that LM-PLA(2)-II induced myotoxic effects both in vitro characterized by an increase on the rate of creatine kinase (CK) release from isolated mice extensor digitorum longus (EDL) muscles and in vivo by increasing plasma CK activity of injected mice. Histological analysis showed an intense damage in muscle cells injected with LM-PLA(2)-II. It was also shown that exogenous lysophosphatidylcholine (lyso-pc) behaved as a typical myotoxin damaging muscle cells, producing myonecrosis characterized by local infiltration of inflammatory cells similarly to that observed for LM-PLA(2)-II. Hemorrhage and lethal effects were not observed neither with LM-PLA(2)-II nor lyso-pc. As previously observed for other biological activities, pretreatment of LM-PLA(2)-II with p-bromophenacyl bromide (p-BPB) or acetic anhydride abolished all the enzyme's actions. The data confirms that biological activities displayed by LM-PLA(2)-II, including the myotoxic effects reported here, are all dependent on its enzymatic activity where the product formed (lyso-pc) may play an important function on such myotoxicity.
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Affiliation(s)
- André L Fuly
- Departamento de Bioquímica Médica, Universidade Federal do Rio de Janeiro, RJ, Rio de Janeiro, Brazil
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43
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Lomonte B, Angulo Y, Santamaría C. Comparative study of synthetic peptides corresponding to region 115–129 in Lys49 myotoxic phospholipases A2 from snake venoms. Toxicon 2003; 42:307-12. [PMID: 14559083 DOI: 10.1016/s0041-0101(03)00149-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lys49 phospholipase A2 homologues constitute a group of catalytically-inactive proteins, present in the venoms of many crotalid snakes, which induce myonecrosis. Current evidence supports the mapping of their toxic site to the C-terminal region, where amino acids comprised within the sequence 115-129 appear to play a central role in toxicity. This study evaluated the possible toxic effects of several synthetic peptides corresponding to the sequence 115-129 of different Lys49 myotoxins, using in vitro cytotoxicity and in vivo myotoxicity assays. Peptides varied widely in their activities, ranging from fully toxic to harmless. Thus, the toxic actions of Lys49 myotoxins cannot always be reproduced by their free peptides 115-129. Peptides from Agkistrodon p. piscivorus (AppK) and A. contortrix laticinctus Lys49 myotoxins exerted both cytotoxicity and myotoxicity. Random scrambling of peptide AppK resulted in complete loss of toxicity, demonstrating that its specific sequence of residues, rather than their simple presence or frequency, confers its ability to damage muscle. Peptide AppK synthesized with D-amino acids retained both activities of the natural L-enantiomer, suggesting that its mechanism of action does not involve the recognition of a proteic receptor/acceptor site on muscle cells, but possibly the binding to other structures, such as negatively-charged membrane phospholipids.
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Affiliation(s)
- Bruno Lomonte
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica.
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44
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Ruller R, Ferreira TL, de Oliveira AHC, Ward RJ. Chemical denaturation of a homodimeric lysine-49 phospholipase A2: a stable dimer interface and a native monomeric intermediate. Arch Biochem Biophys 2003; 411:112-20. [PMID: 12590929 DOI: 10.1016/s0003-9861(02)00712-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Bothropstoxin I (4BthTx-I) is a homodimeric lysine-49 (Lys49) phospholipase A(2) isolated from Bothrops jararacussu venom, which damages liposome membranes via a Ca(2+)-independent mechanism. The stability of the BthTx-I homodimer was evaluated by equilibrium chemical denaturation with guanidinium hydrochloride monitored by changes in the intrinsic tryptophan fluorescence anisotropy, far-UV circular dichroism, dynamic light scattering, and 1-anilinonaphthalene-8-sulfonate binding. Unfolding of the BthTx-I dimer proceeds via a monomeric intermediate with native-like structure, with Gibbs free energy (DeltaG(0)) values of 10.0 and 7.2 kcal mol(-1) for the native dimer-to-native monomer and native-to-denatured monomer transitions, respectively. The experimentally determined DeltaG(0) value for the dimer-to-native monomer transition is higher than the value expected for an interaction dominated by hydrophobic forces, and suggests that an unusually high propensity of hydrogen-bonded side chains found at the BthTx-I homodimer interface make a significant contribution to dimer stability.
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Affiliation(s)
- Roberto Ruller
- Departamento de Bioqui;mica e Immunologia, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
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45
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Angulo Y, Olamendi-Portugal T, Alape-Girón A, Possani LD, Lomonte B. Structural characterization and phylogenetic relationships of myotoxin II from Atropoides (Bothrops) nummifer snake venom, a Lys49 phospholipase A(2) homologue. Int J Biochem Cell Biol 2002; 34:1268-78. [PMID: 12127577 DOI: 10.1016/s1357-2725(02)00060-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In order to analyze its structure-function relationships, the complete amino acid sequence of myotoxin II from Atropoides (Bothrops) nummifer from Costa Rica was determined. This toxin is a Lys49-type phospholipase A(2) (PLA(2)) homologue, devoid of catalytic activity, structurally belonging to class IIA. In addition to the Asp49 --> Lys change in the (inactive) catalytic center, substitutions in the calcium-binding loop suggest that its lack of enzymatic activity is due to the loss of ability to bind Ca(2+). The toxin occurs as a homodimer of basic subunits of 121 residues. Its sequence has highest similarity to Lys49 PLA(2)s from Cerrophidion, Trimeresurus, Bothrops and Agkistrodon species, which form a subfamily of proteins that diverged early from Asp49 PLA(2)s present in the same species, as shown by phylogenetic analysis. The tertiary structure of the toxin was modeled, based on the coordinates of Cerrophidion godmani myotoxin II. Its exposed C-terminal region 115-129 shows several differences in comparison to the homologous sequences of other Lys49 PLA(2)s, i.e. from Agkistrodon p. piscivorus and Bothrops asper. Region 115-129 of the latter two proteins has been implicated in myotoxic activity, on the basis of the direct membrane-damaging of their corresponding synthetic peptides. However, peptide 115-129 of A. nummifer myotoxin II did not exert toxicity upon cultured skeletal muscle cells or mature muscle in vivo. Differences in several amino acid residues, either critical for toxicity, or influencing the conformation of free peptide 115-129 from A. nummifer myotoxin II, may account for its lack of direct membrane-damaging properties.
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Affiliation(s)
- Yamileth Angulo
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
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46
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Kanashiro MM, de Cássia M Escocard R, Petretski JH, Prates MV, Alves EW, Machado OLT, da Silva WD, Kipnis TL. Biochemical and biological properties of phospholipases A(2) from Bothrops atrox snake venom. Biochem Pharmacol 2002; 64:1179-86. [PMID: 12234622 DOI: 10.1016/s0006-2952(02)01288-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholipases A(2) (PLA(2)s), of molecular mass 13-15kDa, are commonly isolated from snake venom. Two myotoxins with PLA(2) activity, BaPLA(2)I and BaPLA(2)III, with estimated molecular masses of 15kDa were isolated from the venom of Bothrops atrox using Sephacryl S-100-HR and reverse-phase chromatography. BaPLA(2)I was basic, with a pI of 9.1, while BaPLA(2)III was neutral with a pI of 6.9. On a molecular basis, BaPLA(2)III exhibited higher catalytic activity on synthetic substrates than BaPLA(2)I. Comparison of the N-terminal residues of BaPLA(2)I with other PLA(2) proteins from snake venoms showed that it has the highest homology (94%) with B. asper myotoxin II and homology with a PLA(2) Lys(49) from B. atrox (89%). In contrast, BaPLA(2)III demonstrated 75, 72, and 71% homology with PLA(2) from Vipera ammodytes meridionalis, B. jararacussu, and B. jararaca, respectively. BaPLA(2)I and BaPLA(2)III were capable, in vitro, of inducing mast cell degranulation and, in vivo, of causing creatine kinase release, edema, and myonecrosis typical of PLA(2)s from snake venoms, characterized by rapid disruption of the plasma membrane as indicated by clumping of myofilaments and necrosis of affected skeletal muscle cells. BaPLA(2)I- and BaPLA(2)III-specific monoclonal and polyclonal antibodies, although incapable of neutralizing PLA(2) edematogenic activity, blocked myonecrosis efficiently in an in vivo neutralization assay. The results presented herein suggest that the biological active site responsible for edema induction by these two PLA(2) enzymes is distinct from the myonecrosis active site and is not dependent upon the catalytic activity of the PLA(2) enzyme.
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Affiliation(s)
- Milton M Kanashiro
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia - LBR, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil
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47
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Lu QM, Jin Y, Wei JF, Li DS, Zhu SW, Wang WY, Xiong YL. Characterization and cloning of a novel phospholipase A(2) from the venom of Trimeresurus jerdonii snake. Toxicon 2002; 40:1313-9. [PMID: 12220717 DOI: 10.1016/s0041-0101(02)00141-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A phospholipase A(2) (PLA(2)), called jerdoxin, was isolated from Trimeresurus jerdonni snake venom and partially characterized. The protein was purified by three chromatographic steps. SDS-polyacrylamide gel electrophoresis in the presence or absence of dithiothreitol showed that it had a molecular mass of 15 kDa. Jerdoxin had an enzymatic activity of 39.4 micro mol/min/mg towards egg yolk phosphatidyl choline (PC). It induced edema in the footpads of mice. In addition, jerdoxin exhibited indirect hemolytic activity. About 97% hemolysis was observed when 2 micro g/ml enzyme was incubated for 90 min in the presence of PC and Ca(2+). No detectable hemolysis was noticed when PC was not added. Ca(2+) was necessary for jerdoxin to exert its hemolytic activity, since only 52% hemolysis was seen when Ca(2+) was absent in the reaction mixture. Furthermore, jerdoxin inhibited ADP induced rabbit platelet aggregation and the inhibition was dose dependent with an IC(50) of 1.0 micro M. The complete amino acid sequence of jerdoxin deduced from cDNA sequence shared high homology with other snake venom PLA(2)s, especially the D 49 PLA(2)s. Also, the residues concerned to Ca(2+) binding were conserved. This is the first report of cDNA sequence of T. jerdonii venom PLA(2).
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Affiliation(s)
- Qiu-Min Lu
- Department of Animal Toxicology, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Yunnan, Kunming, People's Republic of China
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48
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Núñez CE, Angulo Y, Lomonte B. Identification of the myotoxic site of the Lys49 phospholipase A(2) from Agkistrodon piscivorus piscivorus snake venom: synthetic C-terminal peptides from Lys49, but not from Asp49 myotoxins, exert membrane-damaging activities. Toxicon 2001; 39:1587-94. [PMID: 11478967 DOI: 10.1016/s0041-0101(01)00141-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Group II phospholipase A(2) (PLA(2)) myotoxins found in the venoms of Crotalidae snakes can be divided into 'Asp49' and 'Lys49' isoforms, the latter being considered catalytically-inactive variants. Previous studies on one Lys49 isoform, myotoxin II from Bothrops asper, indicated that its myotoxic activity is due to the presence of a short cationic/hydrophobic sequence (115-129) near its C-terminus, which displays membrane-damaging properties. Since the C-terminal region of different group II PLA(2) myotoxins presents considerable sequence variability, synthetic peptides homologous to region 115-129 of myotoxin II, but corresponding to B. asper myotoxin III (Asp49), Agkistrodon piscivorus piscivorus Asp49 PLA(2) and Lys49 PLA(2), were studied to determine the possible functional relevance of such region for the toxic activities of these proteins. Results showed that both Lys49-derived peptides (p-BaK49 and p-AppK49) were able to lyse skeletal muscle C2C12 cells in culture, and to induce edema in the mouse footpad assay. Moreover, p-AppK49, which showed a markedly stronger cytotoxic potency than p-BaK49, additionally induced skeletal muscle necrosis when injected into mice. These observations unequivocally identify the sequence 115-129 (KKYKAYFKLKCKK) of the Lys49 PLA(2) of A. p. piscivorus as containing the key structural determinants needed for myotoxicity, and represent the first report of an unmodified, PLA(2)-derived short synthetic peptide with the ability to reproduce this effect of a parent toxin in vivo. On the other hand, the two Asp49-derived peptides did not show any toxic effects in vitro or in vivo, even at high concentrations. These findings suggests that Lys49 and Asp49 group II PLA(2)s might exert their myotoxic actions through different molecular mechanisms, by implying that the latter may not utilize their C-terminal regions as main membrane-destabilizing elements.
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Affiliation(s)
- C E Núñez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
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49
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Soares AM, Andrião-Escarso SH, Bortoleto RK, Rodrigues-Simioni L, Arni RK, Ward RJ, Gutiérrez JM, Giglio JR. Dissociation of Enzymatic and Pharmacological Properties of Piratoxins-I and -III, Two Myotoxic Phospholipases A2 from Bothrops pirajai Snake Venom. Arch Biochem Biophys 2001; 387:188-96. [PMID: 11370840 DOI: 10.1006/abbi.2000.2244] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Piratoxins (PrTX) I and III are phospholipases A2 (PLA2s) or PLA2 homologue myotoxins isolated from Bothrops pirajai snake venom, which also induce myonecrosis, bactericidal activity against Escherichia coli, disruption of artificial membranes, and edema. PrTX-III is a catalytically active hemolytic and anticoagulant Asp49 PLA2, while PrTX-I is a Lys49 PLA2 homologue, which is catalytically inactive on artificial substrates, but promotes blockade of neuromuscular transmission. Chemical modifications of His, Lys, Tyr, and Trp residues of PrTX-I and PrTX-III were performed, together with cleavage of the N-terminal octapeptide by CNBr and inhibition by heparin and EDTA. The lethality, bactericidal activity, myotoxicity, neuromuscular effect, edema inducing effect, catalytic and anticoagulant activities, and the liposome-disruptive activity of the modified toxins were evaluated. A complex pattern of functional differences between the modified and native toxins was observed. However, in general, chemical modifications that significantly affected the diverse pharmacological effects of the toxins did not influence catalytic or membrane disrupting activities. Analysis of structural changes by circular dichroism spectroscopy demonstrated significant changes in the secondary structure only in the case of N-terminal octapeptide cleavage. These data indicate that PrTX-I and PrTX-III possess regions other than the catalytic site, which determine their toxic and pharmacological activities.
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Affiliation(s)
- A M Soares
- Departamento de Bioquímica e Immunologia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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50
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Ward RJ, de Oliveira AH, Bortoleto RK, Rosa JC, Faça VM, Greene LJ. Refolding and purification of Bothropstoxin-I, a Lys49-phospholipase A2 homologue, expressed as inclusion bodies in Escherichia coli. Protein Expr Purif 2001; 21:134-40. [PMID: 11162398 DOI: 10.1006/prep.2000.1353] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hydrolysis of phospholipids by Group II phospholipase A2 enzymes involves a nucleophilic attack on the sn-2 ester bond by the His48 residue and stabilization of the reaction intermediate by a Ca2+ ion cofactor bound to the Asp49 residue in the protein active site region. Bothropstoxin-I (BthTX-I) is a PLA(2) variant present in the venom of the snake Bothrops jararacussu which shows a Asp49 to Lys substitution and which lacks hydrolytic activity yet damages artificial membranes by a noncatalytic Ca2+-independent mechanism. In order to better characterize this unusual mechanism of membrane damage, we have established an expression system for BthTX-I in Escherichia coli. The DNA-coding sequence for BthTX-I was subcloned into the vector pET11-d, and the BthTX-I was expressed as inclusion bodies in E. coli BL21(DE3). The native BthTX-I contains seven disulfide bonds, and a straightforward protocol has been developed to refold the recombinant protein at high protein concentration in the presence of surfactants using a size-exclusion chromatography matrix. After refolding, recovery yields of 2.5% (corresponding to 4-5 mg of refolded recombinant BthTX-I per liter of bacterial culture) were routinely obtained. After refolding, identical fluorescent and circular dichroism spectra were obtained for the recombinant BthTX-I compared to those of the native protein. Furthermore, the native and refolded recombinant protein demonstrated identical membrane-damaging properties as evaluated by measuring the release of an entrapped fluorescent marker from liposomes.
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Affiliation(s)
- R J Ward
- Department of Chemistry, Protein Chemistry Center, Universidiade de São Paulo, São Paulo, Brazil.
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