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Averin A, Starkov V, Tsetlin V, Utkin Y. Effects of the Heterodimeric Neurotoxic Phospholipase A 2 from the Venom of Vipera nikolskii on the Contractility of Rat Papillary Muscles and Thoracic Aortas. Toxins (Basel) 2024; 16:100. [PMID: 38393179 PMCID: PMC10891809 DOI: 10.3390/toxins16020100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/03/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Phospholipases A2 (PLA2s) are a large family of snake toxins manifesting diverse biological effects, which are not always related to phospholipolytic activity. Snake venom PLA2s (svPLA2s) are extracellular proteins with a molecular mass of 13-14 kDa. They are present in venoms in the form of monomers, dimers, and larger oligomers. The cardiovascular system is one of the multiple svPLA2 targets in prey organisms. The results obtained previously on the cardiovascular effects of monomeric svPLA2s were inconsistent, while the data on the dimeric svPLA2 crotoxin from the rattlesnake Crotalus durissus terrificus showed that it significantly reduced the contractile force of guinea pig hearts. Here, we studied the effects of the heterodimeric svPLA2 HDP-1 from the viper Vipera nikolskii on papillary muscle (PM) contractility and the tension of the aortic rings (ARs). HDP-1 is structurally different from crotoxin, and over a wide range of concentrations, it produced a long-term, stable, positive inotropic effect in PMs, which did not turn into contractures at the concentrations studied. This also distinguishes HDP-1 from the monomeric svPLA2s, which at high concentrations inhibited cardiac function. HDP-1, when acting on ARs preconstricted with 10 μM phenylephrine, induced a vasorelaxant effect, similar to some other svPLA2s. These are the first indications of the cardiac and vascular effects of true vipers' heterodimeric svPLA2s.
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Affiliation(s)
- Alexey Averin
- Institute of Cell Biophysics, Federal Research Center “Pushchino Scientific Center of Biological Research”, Pushchino Branch, Russian Academy of Sciences, Pushchino 142290, Russia;
| | - Vladislav Starkov
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; (V.S.); (V.T.)
| | - Victor Tsetlin
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; (V.S.); (V.T.)
| | - Yuri Utkin
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; (V.S.); (V.T.)
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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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Doltchinkova V, Stoylov S, Angelova PR. Viper toxins affect membrane characteristics of human erythrocytes. Biophys Chem 2020; 270:106532. [PMID: 33360945 DOI: 10.1016/j.bpc.2020.106532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 10/22/2022]
Abstract
Elucidating electrokinetic stability by which surface charges regulate toxins interaction with erythrocytes is crucial for understanding the cell functionality. Electrokinetic properties of human erythrocytes upon treatment of Vipoxin, phospholipase A2 (PLA2) and Vipoxin acidic component (VAC), isolated from Vipera ammodytes meridionalis venom were studied using particle microelectrophoresis. PLA2 and Vipoxin treatments alter the osmotic fragility of erythrocyte membranes. The increased stability of cells upon viper toxins is presented by the increased zeta potential of erythrocytes before sedimentation of cells during electric field applied preventing the aggregation of cells. Lipid peroxidation of low dose toxin-treated erythrocytes shows reduced LP products compared to untreated cells. The apparent proton efflux and conductivity assays are performed and the effectiveness PLA2 > Vipoxin>VAC is discussed. The reported results open perspectives to a further investigation of the electrokinetic properties of the membrane after viper toxins treatment to shed light on the molecular mechanisms driving the mechanisms of inflammation and neurodegenerative diseases.
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Affiliation(s)
- Virjinia Doltchinkova
- Department of Biophysics and Radiobiology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 1164 Sofia, Bulgaria.
| | - Stoyl Stoylov
- "Rostislaw Kaischew" Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Plamena R Angelova
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
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Nirthanan S. Snake three-finger α-neurotoxins and nicotinic acetylcholine receptors: molecules, mechanisms and medicine. Biochem Pharmacol 2020; 181:114168. [PMID: 32710970 DOI: 10.1016/j.bcp.2020.114168] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 12/13/2022]
Abstract
Snake venom three-finger α-neurotoxins (α-3FNTx) act on postsynaptic nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction (NMJ) to produce skeletal muscle paralysis. The discovery of the archetypal α-bungarotoxin (α-BgTx), almost six decades ago, exponentially expanded our knowledge of membrane receptors and ion channels. This included the localisation, isolation and characterization of the first receptor (nAChR); and by extension, the pathophysiology and pharmacology of neuromuscular transmission and associated pathologies such as myasthenia gravis, as well as our understanding of the role of α-3FNTxs in snakebite envenomation leading to novel concepts of targeted treatment. Subsequent studies on a variety of animal venoms have yielded a plethora of novel toxins that have revolutionized molecular biomedicine and advanced drug discovery from bench to bedside. This review provides an overview of nAChRs and their subtypes, classification of α-3FNTxs and the challenges of typifying an increasing arsenal of structurally and functionally unique toxins, and the three-finger protein (3FP) fold in the context of the uPAR/Ly6/CD59/snake toxin superfamily. The pharmacology of snake α-3FNTxs including their mechanisms of neuromuscular blockade, variations in reversibility of nAChR interactions, specificity for nAChR subtypes or for distinct ligand-binding interfaces within a subtype and the role of α-3FNTxs in neurotoxic envenomation are also detailed. Lastly, a reconciliation of structure-function relationships between α-3FNTx and nAChRs, derived from historical mutational and biochemical studies and emerging atomic level structures of nAChR models in complex with α-3FNTxs is discussed.
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Affiliation(s)
- Selvanayagam Nirthanan
- School of Medical Science, Griffith Health Group, Griffith University, Gold Coast, Queensland, Australia.
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Rodrigues CFB, Ferreira MJP, Belchor MN, Costa CRC, Novaes DP, Dos Santos Junior AB, Tamayose CI, Pinho MVT, de Oliveira MA, Toyama MH. Evaluation of the Inhibitory Potential of Casuarictin, an Ellagitannin Isolated from White Mangrove ( Laguncularia racemosa) Leaves, on Snake Venom Secretory Phospholipase A2. Mar Drugs 2019; 17:md17070403. [PMID: 31288445 PMCID: PMC6669752 DOI: 10.3390/md17070403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/10/2019] [Accepted: 06/19/2019] [Indexed: 12/31/2022] Open
Abstract
Ellagitannins constitute the largest group of hydrolyzable tannins of plants, and, from this group, casuarictin (Casu) was identified in some plant species. However, to our knowledge, no investigation of secretory phospholipase A2 (sPLA2) inhibition by Casu has been performed yet. Casuarictin was isolated by chromatography n-butanol (n-BuOH) partition of Laguncularia racemosa leaves. The pharmacological and biological effects of Casu were evaluated on isolated sPLA2 from the rattlesnake (Crotalus durissus terrificus) and using a plant bacterial strain. The compound was able to form a protein complex consisting of a stable sPLA2 + Casu complex. Analyses carried out with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF) revealed that the molecular mass of sPLA2 increased from 14,425.62 to 15,362.74 Da. The enzymatic activity of the sPLA2 + Casu complex was significantly lower than that of native sPLA2. Besides, molecular interactions of Casu with sPLA2 were able to virtually abolish the native edematogenic effect as well as myonecrosis induced by the protein when injected 10 min after sPLA2. Therefore, Casu may be considered a potential anti-inflammatory that can be used to treat edema and myonecrosis induced by serine-secreting phospholipase A2. In addition, the compound also showed great antimicrobial potential.
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Affiliation(s)
- Caroline Fabri Bittencourt Rodrigues
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
- Laboratório de Herpetologia, Instituto Butantan, São Paulo 05503-900, São Paulo, Brazil
| | - Marcelo José Pena Ferreira
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Mariana Novo Belchor
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Caroline R C Costa
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Danielle P Novaes
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Adeilso Bispo Dos Santos Junior
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Cinthia I Tamayose
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Marcus Vinícius Terashima Pinho
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Marcos Antonio de Oliveira
- Laboratório de Biologia Molecular Estrutural (LABIMES), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil
| | - Marcos Hikari Toyama
- Laboratório de Bioquímica e Biologia Molecular de Peptídeos (BIOMOLPEP), Instituto de Biociências, UNESP, Campus do Litoral Paulista, São Vicente 11330-900, São Paulo, Brazil.
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Action of Vipoxin and its separated components on monomolecular film of Dilauroylphosphatidylcholine at the air/water interface. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.11.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhou B, Liu G, He Q, Li B, Yu X. Dacin, one metalloproteinase from Deinagkistrodon acutus venom inhibiting contraction of mouse ileum muscle. BMC BIOCHEMISTRY 2017; 18:11. [PMID: 28701157 PMCID: PMC5508760 DOI: 10.1186/s12858-017-0086-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 07/03/2017] [Indexed: 11/26/2022]
Abstract
Background Mice were bitten by five-pace vipers (Deinagkistrodon acutus), and then envenomed. It was well-known that the snake venom mainly disturbed the blood homeostasis of the envenomed victims. Ocassionally, we found that the venom of D. acutus could inhibit the contraction tension of mouse ileum, so in this study we aimed to identify the active component inhibiting the contraction tension of mouse ileum in the snake venom. Results The active component inhibiting the contraction tension of mouse ileum, designated as Dacin, was isolated from D. acutus venom, purified to protein homogeneity and composed of a single peptide chain, about 23 kDa analyzed by SDS-PAGE, and 22, 947. 9 Da measured by MALDI-TOF-MS. Not only the results of its PMF blasted by Mascot indicated that Dacin may be one snake venom metalloproteinase (SVMP), but also the results of the biochemical and in-vivo assays as follow demonstrated that it was one SVMP: it cleaved Aα and Bβ chains, not Cγ of bovine fibrinogen within 1 h, and also hydrolyzed fibrin polymer; besides its fibrino(geno)lytic activities were strongly inhibited by β- mercaptoethanol, EDTA and EGTA; and it could induce a hemorrhagic reaction under the dorsal skin of mouse. In the isolated tissue assays, Dacin caused the concentration-dependent and time-dependent inhibitory actions on the spontaneous contraction tension of the ileum smooth muscle of mouse, and the inhibitory effects were irreversible. Conclusions Taken together, for the first time one active component (Dacin, a SVMP) that irreversibly inhibited the spontaneous contraction tension of mouse ileum has been isolated and identified from D. acutus venom. The findings may provide not only a new insight for toxicological researches on SVMPs and venoms of the vipers, but also a reference for clinicians to treat the snake-bitten victims. However, Dacin’s inhibitory molecular mechanism will be further studied in the future.
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Affiliation(s)
- Bin Zhou
- Animal Toxin Group, Chongqing Key Laboratory of Animal Biology, Chongqing Engineering Research Center of Bioactive Substance, Engineering Research Center of Active Substance and Biotechnology, Ministry of Education, Collaborative Innovation Center of Breeding and Deep Processing of Venomous Snakes, College of Life Science, Chongqing Normal University, Chongqing, 401331, China.,Library, Chongqing Normal University, Chongqing, 401331, China
| | - Gang Liu
- Animal Toxin Group, Chongqing Key Laboratory of Animal Biology, Chongqing Engineering Research Center of Bioactive Substance, Engineering Research Center of Active Substance and Biotechnology, Ministry of Education, Collaborative Innovation Center of Breeding and Deep Processing of Venomous Snakes, College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Qiyi He
- Animal Toxin Group, Chongqing Key Laboratory of Animal Biology, Chongqing Engineering Research Center of Bioactive Substance, Engineering Research Center of Active Substance and Biotechnology, Ministry of Education, Collaborative Innovation Center of Breeding and Deep Processing of Venomous Snakes, College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Bo Li
- Animal Toxin Group, Chongqing Key Laboratory of Animal Biology, Chongqing Engineering Research Center of Bioactive Substance, Engineering Research Center of Active Substance and Biotechnology, Ministry of Education, Collaborative Innovation Center of Breeding and Deep Processing of Venomous Snakes, College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Xiaodong Yu
- Animal Toxin Group, Chongqing Key Laboratory of Animal Biology, Chongqing Engineering Research Center of Bioactive Substance, Engineering Research Center of Active Substance and Biotechnology, Ministry of Education, Collaborative Innovation Center of Breeding and Deep Processing of Venomous Snakes, College of Life Science, Chongqing Normal University, Chongqing, 401331, China.
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Chan YS, Cheung RCF, Xia L, Wong JH, Ng TB, Chan WY. Snake venom toxins: toxicity and medicinal applications. Appl Microbiol Biotechnol 2016; 100:6165-6181. [PMID: 27245678 DOI: 10.1007/s00253-016-7610-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/01/2016] [Accepted: 05/03/2016] [Indexed: 11/25/2022]
Abstract
Snake venoms are complex mixtures of small molecules and peptides/proteins, and most of them display certain kinds of bioactivities. They include neurotoxic, cytotoxic, cardiotoxic, myotoxic, and many different enzymatic activities. Snake envenomation is a significant health issue as millions of snakebites are reported annually. A large number of people are injured and die due to snake venom poisoning. However, several fatal snake venom toxins have found potential uses as diagnostic tools, therapeutic agent, or drug leads. In this review, different non-enzymatically active snake venom toxins which have potential therapeutic properties such as antitumor, antimicrobial, anticoagulating, and analgesic activities will be discussed.
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Affiliation(s)
- Yau Sang Chan
- State Key Laboratory of Respiratory Disease for Allergy, School of Medicine, Shenzhen University, Nanhai Ave 3688, 518060, Shenzhen, Guangdong, China
| | - Randy Chi Fai Cheung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Lixin Xia
- State Key Laboratory of Respiratory Disease for Allergy, School of Medicine, Shenzhen University, Nanhai Ave 3688, 518060, Shenzhen, Guangdong, China.
| | - Jack Ho Wong
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
| | - Tzi Bun Ng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
| | - Wai Yee Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
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Hassan-Puttaswamy V, Adams DJ, Kini RM. A Distinct Functional Site in Ω-Neurotoxins: Novel Antagonists of Nicotinic Acetylcholine Receptors from Snake Venom. ACS Chem Biol 2015; 10:2805-15. [PMID: 26448325 DOI: 10.1021/acschembio.5b00492] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Snake venom α-neurotoxins from the three-finger toxin (3FTx) family are competitive antagonists with nanomolar affinity and high selectivity for nicotinic acetylcholine receptors (nAChR). Here, we report the characterization of a new group of competitive nAChR antagonists: Ω-neurotoxins. Although they belong to the 3FTx family, the characteristic functional residues of α-neurotoxins are not conserved. We evaluated the subtype specificity and structure-function relationships of Oh9-1, an Ω-neurotoxin from Ophiophagus hannah venom. Recombinant Oh9-1 showed reversible postsynaptic neurotoxicity in the micromolar range. Experiments with different nAChR subtypes expressed in Xenopus oocytes indicated Oh9-1 is selective for rat muscle type α1β1εδ (adult) and α1β1γδ (fetal) and rat neuronal α3β2 subtypes. However, Oh9-1 showed low or no affinity for other human and rat neuronal subtypes. Twelve individual alanine-scan mutants encompassing all three loops of Oh9-1 were evaluated for binding to α1β1εδ and α3β2 subtypes. Oh9-1's loop-II residues (M25, F27) were the most critical for interactions and formed the common binding core. Mutations at T23 and F26 caused a significant loss in activity at α1β1εδ receptors but had no effect on the interaction with the α3β2 subtype. Similarly, mutations at loop-II (H7, K22, H30) and -III (K45) of Oh9-1 had a distinctly different impact on its activity with these subtypes. Thus, Oh9-1 interacts with these nAChRs via distinct residues. Unlike α-neurotoxins, the tip of loop-II is not involved. We reveal a novel mode of interaction, where both sides of the β-strand of Oh9-1's loop-II interact with α1β1εδ, but only one side interacts with α3β2. Phylogenetic analysis revealed functional organization of the Ω-neurotoxins independent of α-neurotoxins. Thus, Ω-neurotoxin: Oh9-1 may be a new, structurally distinct class of 3FTxs that, like α-neurotoxins, antagonize nAChRs. However, Oh9-1 binds to the ACh binding pocket via a different set of functional residues.
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Affiliation(s)
| | - David J. Adams
- Health
Innovations Research Institute, RMIT University, Melbourne, Victoria 3083, Australia
| | - R. Manjunatha Kini
- Department
of Biological Sciences, National University of Singapore, Singapore 117543
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Doumanov J, Mladenova K, Aleksandrov R, Danovski G, Petrova S. Interactions of pharmacologically active snake venom sPLA 2 with different cell lines. BIOTECHNOL BIOTEC EQ 2014; 28:918-922. [PMID: 26019578 PMCID: PMC4433929 DOI: 10.1080/13102818.2014.965014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/27/2014] [Indexed: 12/03/2022] Open
Abstract
Secreted Phospholipases A2 (sPLA2s) represent a large family of structurally related enzymes, which target different tissues and organs and induce numerous pharmacological effects based on their catalytic specificity – hydrolysis of the sn-2 ester bond of glycerophospholipids. The neurotoxin vipoxin, isolated from the venom of Vipera ammodytes meriodionalis, is a heterodimeric postsynaptic ionic complex composed of two protein subunits – a basic and toxic His48 sPLA2 enzyme and an acidic, enzymatically inactive and non-toxic component. In this paper, for the first time, we demonstrate that vipoxin sPLA2 enzyme affects cell integrity and viability of four cell types and causes different cell responses. The most dramatic local tissue effects were observed with RPE-1 (retinal pigment epithelial) cells followed by A549 (adenocarcinomic human alveolar epithelial) cells and MDCK (Madin-Darby Canine Kidney epithelial) cells. Products of the enzymatic reaction, lysophospholipids and unsaturated free fatty acids, act as lipid mediators that can induce membrane damaging or can stimulate cell proliferation. Our preliminary results on the cytotoxic effect of vipoxin sPLA2 on A549 cells are promising in searching of its eventual anticancer potential.
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Affiliation(s)
- Jordan Doumanov
- Department of Biochemistry, Faculty of Biology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria
| | - Kirilka Mladenova
- Department of Biochemistry, Faculty of Biology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria
| | - Radoslav Aleksandrov
- Department of Biochemistry, Faculty of Biology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria
| | - Georgi Danovski
- Department of Biochemistry, Faculty of Biology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria
| | - Svetla Petrova
- Department of Biochemistry, Faculty of Biology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria
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