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Ayvazyan NM, O'Leary VB, Dolly JO, Ovsepian SV. Neurobiology and therapeutic utility of neurotoxins targeting postsynaptic mechanisms of neuromuscular transmission. Drug Discov Today 2019; 24:1968-1984. [PMID: 31247153 DOI: 10.1016/j.drudis.2019.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 11/28/2022]
Abstract
The neuromuscular junction (NMJ) is the principal site for the translation of motor neurochemical signals to muscle activity. Therefore, the release and sensing machinery of acetylcholine (ACh) along with muscle contraction are two of the main targets of natural toxins and pathogens, causing paralysis. Given pharmacology and medical advances, the active ingredients of toxins that target postsynaptic mechanisms have become of major interest, showing promise as drug leads. Herein, we review key facets of prevalent toxins modulating the mechanisms of ACh sensing and generation of the postsynaptic response, with muscle contraction. We consider the correlation between their outstanding selectivity and potency plus effects on motor function, and discuss emerging data advocating their usage for the development of therapies alleviating neuromuscular dysfunction.
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Affiliation(s)
- Naira M Ayvazyan
- Orbeli Institute of Physiology, National Academy of Sciences of the Republic of Armenia, Yerevan, Armenia.
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland
| | - Saak V Ovsepian
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland; The National Institute of Mental Health, Topolová 748, Klecany, Czech Republic; Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic.
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2
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Barber CM, Isbister GK, Hodgson WC. Alpha neurotoxins. Toxicon 2013; 66:47-58. [PMID: 23416229 DOI: 10.1016/j.toxicon.2013.01.019] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/29/2013] [Indexed: 10/27/2022]
Abstract
α-Neurotoxins have been isolated from hydrophid, elapid and, more recently, colubrid snake venoms. Also referred to as postsynaptic neurotoxins or 'curare mimetic' neurotoxins, they play an important role in the capture and/or killing of prey by binding to the nicotinic acetylcholine receptor on the skeletal muscle disrupting neurotransmission. They are also thought to cause respiratory paralysis in envenomed humans. This review will discuss the historical background into the discovery, isolation, structure and mechanism of action of the α-neurotoxins, including targets and cellular outcomes, and then will examine the potential uses of α-neurotoxins as pharmacological tools and/or as drug leads.
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Affiliation(s)
- Carmel M Barber
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
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Johnston CI, O'Leary MA, Brown SGA, Currie BJ, Halkidis L, Whitaker R, Close B, Isbister GK. Death adder envenoming causes neurotoxicity not reversed by antivenom--Australian Snakebite Project (ASP-16). PLoS Negl Trop Dis 2012; 6:e1841. [PMID: 23029595 PMCID: PMC3459885 DOI: 10.1371/journal.pntd.0001841] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 08/16/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Death adders (Acanthophis spp) are found in Australia, Papua New Guinea and parts of eastern Indonesia. This study aimed to investigate the clinical syndrome of death adder envenoming and response to antivenom treatment. METHODOLOGY/PRINCIPAL FINDINGS Definite death adder bites were recruited from the Australian Snakebite Project (ASP) as defined by expert identification or detection of death adder venom in blood. Clinical effects and laboratory results were collected prospectively, including the time course of neurotoxicity and response to treatment. Enzyme immunoassay was used to measure venom concentrations. Twenty nine patients had definite death adder bites; median age 45 yr (5-74 yr); 25 were male. Envenoming occurred in 14 patients. Two further patients had allergic reactions without envenoming, both snake handlers with previous death adder bites. Of 14 envenomed patients, 12 developed neurotoxicity characterised by ptosis (12), diplopia (9), bulbar weakness (7), intercostal muscle weakness (2) and limb weakness (2). Intubation and mechanical ventilation were required for two patients for 17 and 83 hours. The median time to onset of neurotoxicity was 4 hours (0.5-15.5 hr). One patient bitten by a northern death adder developed myotoxicity and one patient only developed systemic symptoms without neurotoxicity. No patient developed venom induced consumption coagulopathy. Antivenom was administered to 13 patients, all receiving one vial initially. The median time for resolution of neurotoxicity post-antivenom was 21 hours (5-168). The median peak venom concentration in 13 envenomed patients with blood samples was 22 ng/mL (4.4-245 ng/mL). In eight patients where post-antivenom bloods were available, no venom was detected after one vial of antivenom. CONCLUSIONS/SIGNIFICANCE Death adder envenoming is characterised by neurotoxicity, which is mild in most cases. One vial of death adder antivenom was sufficient to bind all circulating venom. The persistent neurological effects despite antivenom, suggests that neurotoxicity is not reversed by antivenom.
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Affiliation(s)
- Christopher I. Johnston
- School of Medicine Sydney, University of Notre Dame Australia, Darlinghurst, New South Wales, Australia
- NSW Poisons Information Centre, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Margaret A. O'Leary
- Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle and the Discipline of Clinical Pharmacology, University of Newcastle, Newcastle, New South Wales, Australia
| | - Simon G. A. Brown
- Centre for Clinical Research in Emergency Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and University of Western Australia, Perth, Western Australia, Australia
| | - Bart J. Currie
- Menzies School of Health Research and Northern Territory Clinical School, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Lambros Halkidis
- Emergency Department, Cairns Base Hospital, Cairns, Queensland, Australia
| | - Richard Whitaker
- Emergency Department, Cairns Base Hospital, Cairns, Queensland, Australia
| | - Benjamin Close
- Emergency Department, The Townsville Hospital, Townsville, Queensland, Australia
| | - Geoffrey K. Isbister
- NSW Poisons Information Centre, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle and the Discipline of Clinical Pharmacology, University of Newcastle, Newcastle, New South Wales, Australia
- * E-mail:
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Pintor AF, Winter KL, Krockenberger AK, Seymour JE. Venom physiology and composition in a litter of Common Death Adders (Acanthophis antarcticus) and their parents. Toxicon 2011; 57:68-75. [DOI: 10.1016/j.toxicon.2010.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 10/19/2022]
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Blacklow B, Kornhauser R, Hains PG, Loiacono R, Escoubas P, Graudins A, Nicholson GM. α-Elapitoxin-Aa2a, a long-chain snake α-neurotoxin with potent actions on muscle (α1)2βγδ nicotinic receptors, lacks the classical high affinity for neuronal α7 nicotinic receptors. Biochem Pharmacol 2011; 81:314-25. [DOI: 10.1016/j.bcp.2010.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 10/02/2010] [Accepted: 10/05/2010] [Indexed: 10/19/2022]
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Kuruppu S, Smith AI, Isbister GK, Hodgson WC. Neurotoxins From Australo-Papuan Elapids: A Biochemical and Pharmacological Perspective. Crit Rev Toxicol 2008; 38:73-86. [DOI: 10.1080/10408440701703964] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
Australia is home to a vast collection of highly venomous terrestrial and marine snakes. As such, Australia has proven to be an excellent source of investigative material for both local and international toxinologists. Research on snake venoms initially focussed on identifying the most lethal species, and the venom components responsible for the lethality, so that treatment strategies could be implemented. Since then, the focus of research has included the isolation and characterisation of toxins (primarily neurotoxins), examination of the efficacy of commercially available antivenoms and, more recently, the use of liquid chromatography/mass spectrometry (LCMS) to aid in the analysis of whole venoms. Given the vast quantity of research undertaken over the past 70 yr we have tried to provide a short insight into some of this excellent work and identify areas requiring further examination.
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Affiliation(s)
- Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Monash University, Victoria 3800, Australia.
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Wickramaratna JC, Fry BG, Loiacono RE, Aguilar MI, Alewood PF, Hodgson WC. Isolation and characterization at cholinergic nicotinic receptors of a neurotoxin from the venom of the Acanthophis sp. Seram death adder. Biochem Pharmacol 2004; 68:383-94. [PMID: 15194010 DOI: 10.1016/j.bcp.2004.03.033] [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: 02/14/2004] [Accepted: 03/25/2004] [Indexed: 10/26/2022]
Abstract
The present study describes the isolation of the first neurotoxin (acantoxin IVa) from Acanthophis sp. Seram death adder venom and an examination of its activity at nicotinic acetylcholine receptor (nAChR) subtypes. Acantoxin IVa (MW 6815; 0.1-1.0 microM) caused concentration-dependent inhibition of indirect twitches (0.1 Hz, 0.2 ms, supramaximal V) and inhibited contractile responses to exogenous nicotinic agonists in the chick biventer cervicis nerve-muscle, confirming that this toxin is a postsynaptic neurotoxin. Acantoxin IVa (1-10 nM) caused pseudo-irreversible antagonism at skeletal muscle nAChR with an estimated pA2 of 8.36+/-0.17. Acantoxin IVa was approximately two-fold less potent than the long-chain (Type II) neurotoxin, alpha-bungarotoxin. With a pKi value of 4.48, acantoxin IVa was approximately 25,000 times less potent than alpha-bungarotoxin at alpha7-type neuronal nAChR. However, in contrast to alpha-bungarotoxin, acantoxin IVa completely inhibited specific [3H]-methyllycaconitine (MLA) binding in rat hippocampus homogenate. Acantoxin IVa had no activity at ganglionic nAChR, alpha4beta2 subtype neuronal nAChR or cytisine-resistant [3H]-epibatidine binding sites. While long-chain neurotoxin resistant [3H]-MLA binding in hippocampus homogenate requires further investigation, we have shown that a short-chain (Type I) neurotoxin is capable of fully inhibiting specific [3H]-MLA binding.
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Wickramaratna JC, Fry BG, Hodgson WC. Species-dependent variations in the in vitro myotoxicity of death adder (Acanthophis) venoms. Toxicol Sci 2003; 74:352-60. [PMID: 12773755 DOI: 10.1093/toxsci/kfg144] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Based on early studies on Acanthophis antarcticus (common death adder) venom, it has long been thought that death adder snake venoms are devoid of myotoxicity. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus. Subsequently, a myotoxic phospholipase A2 component was isolated from A. rugosus (Irian Jayan death adder) venom. The present study examined the venoms of A. praelongus (northern), A. pyrrhus (desert), A. hawkei (Barkly Tableland), A. wellsi (black head), A. rugosus, A. sp. Seram and the regional variants of A. antarcticus for in vitro myotoxicity. Venoms (10-50 microg/ml) were examined for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. All venoms displayed high phospholipase A2 activity. The venoms (10-50 microg/ml) of A. sp. Seram, A. praelongus, A. rugosus,and A. wellsi caused a significant inhibition of direct twitches and an increase in baseline tension compared to the vehicle (n=4-6; two-way ANOVA, p<0.05). Furthermore, these venoms caused dose-dependent morphological changes in skeletal muscle. In contrast, the venoms (10-50 microg/ml; n=3-6) of A. hawkei, A. pyrrhus, and regional variants of A. antarcticus were devoid of myotoxicity. Prior incubation (10 min) of CSL death adder antivenom (5 U/ml) prevented the myotoxicity caused by A. sp. Seram, A. praelongus, A. rugosus, and A. wellsi venoms (50 microg/ml; n=4-7). In conclusion, clinicians may need to be mindful of possible myotoxicity following envenomations by A. praelongus, A. rugosus, A. sp. Seram, and A. wellsi species.
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Affiliation(s)
- Janith C Wickramaratna
- Monash Venom Group, Department of Pharmacology, Monash University, Victoria 3800, Australia
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Wickramaratna JC, Fry BG, Aguilar MI, Kini RM, Hodgson WC. Isolation and pharmacological characterization of a phospholipase A2 myotoxin from the venom of the Irian Jayan death adder (Acanthophis rugosus). Br J Pharmacol 2003; 138:333-42. [PMID: 12540524 PMCID: PMC1573671 DOI: 10.1038/sj.bjp.0705046] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. It has long been thought that death adder venoms are devoid of myotoxic activity based on studies done on Acanthophis antarcticus (Common death adder) venom. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus. Consequently, the present study examined A. rugosus (Irian Jayan death adder) venom for myotoxicity, and isolated the first myotoxin (acanmyotoxin-1) from a death adder venom. 2. A. rugosus (10-50 micro g ml(-1)) and acanmyotoxin-1 (MW 13811; 0.1-1 micro M) were screened for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle (CBCNM) preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. 3. High phospholipase A(2) (PLA(2)) activity was detected in both A. rugosus venom (140.2+/-10.4 micro mol min(-1) mg(-1); n=6) and acanmyotoxin-1 (153.4+/-11 micro mol min(-1) mg(-1); n=6). Both A. rugosus venom (10-50 micro g ml(-1)) and acanmyotoxin-1 (0.1-1 micro M) caused dose-dependent inhibition of direct twitches and increase in baseline tension (n=4-6). In addition, dose-dependent morphological changes in skeletal muscle were observed. 4. Prior incubation (10 min) of CSL death adder antivenom (5 units ml(-1); n=4) or inactivation of PLA(2) activity with 4-bromophenacyl bromide (1.8 mM; n=4) prevented the myotoxicity caused by acanmyotoxin-1 (1 micro M). 5. Acanmyotoxin-1 (0.1 micro M; n=4) displayed no significant neurotoxicity when it was examined using the indirectly (0.1 Hz, 0.2 ms, supramaximal V) stimulated CBCNM preparation. 6. In conclusion, clinicians may need to be mindful of possible myotoxicity following death adder envenomation in Irian Jaya.
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Affiliation(s)
- Janith C Wickramaratna
- Monash Venom Group, Department of Pharmacology, P.O. Box 13E, Monash University, Victoria 3800, Australia
| | - Bryan G Fry
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260
- Australian Venom Research Unit, Department of Pharmacology, University of Melbourne, Victoria 3010, Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology, P.O. Box 13D, Monash University, Victoria 3800, Australia
| | - R Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 119260
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, P.O. Box 13E, Monash University, Victoria 3800, Australia
- Author for correspondence:
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Fry BG, Wickramaratna JC, Jones A, Alewood PF, Hodgson WC. Species and regional variations in the effectiveness of antivenom against the in vitro neurotoxicity of death adder (Acanthophis) venoms. Toxicol Appl Pharmacol 2001; 175:140-8. [PMID: 11543646 DOI: 10.1006/taap.2001.9233] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although viperlike in appearance and habit, death adders belong to the Elapidae family of snakes. Systemic envenomation represents a serious medical problem with antivenom, which is raised against Acanthophis antarcticus venom, representing the primary treatment. This study focused on the major Acanthophis variants from Australia and islands in the Indo-Pacific region. Venoms were profiled using liquid chromatography-mass spectrometry, and analyzed for in vitro neurotoxicity (0.3-10 microg/ml), as well as the effectiveness of antivenom (1-5 units/ml; 10 min prior to the addition of 10 microg/ml venom). The following death adder venoms were examined: A. antarcticus (from separate populations in New South Wales, Queensland, South Australia, and Western Australia), A. hawkei, A. praelongus, A. pyrrhus, A. rugosus, A. wellsi, and venom from an unnamed species from the Indonesian island of Seram. All venoms abolished indirect twitches of the chick isolated biventer cervicis nerve-muscle preparation in a dose-dependent manner. In addition, all venoms blocked responses to exogenous acetylcholine (1 mM) and carbachol (20 microM), but not KCl (40 mM), suggesting postsynaptic neurotoxicity. Death adder antivenom (1 unit/ml) prevented the neurotoxic effects of A. pyrrhus, A. praelongus, and A. hawkei venoms, although it was markedly less effective against venoms from A. antarcticus (NSW, SA, WA), A. rugosus, A. wellsi, and A. sp. Seram. However, at 5 units/ml, antivenom was effective against all venoms tested. Death adder venoms, including those from A. antarcticus geographic variants, differed not only in their venom composition but also in their neurotoxic activity and susceptibility to antivenom. For the first time toxicological aspects of A. hawkei, A. wellsi, A. rugosus, and A. sp. Seram venoms were studied.
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Affiliation(s)
- B G Fry
- The Centre for Drug Design and Development, University of Queensland, St. Lucia, Queensland, 4072, Australia
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Wickramaratna JC, Hodgson WC. A pharmacological examination of venoms from three species of death adder (Acanthophis antarcticus, Acanthophis praelongus and Acanthophis pyrrhus). Toxicon 2001; 39:209-16. [PMID: 10978738 DOI: 10.1016/s0041-0101(00)00117-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The common (A. antarcticus), northern (A. praelongus) and desert (A. pyrrhus) death adders are species belonging to the Acanthophis genus. The present study compared some pharmacological aspects of the venoms of these species and examined the in vitro efficacy of death adder antivenom. Neurotoxicity was determined by the time to produce 90% inhibition (t(90)) of indirect (0.1 Hz, 0.2 ms, supramaximal voltage) twitches in the chick biventer cervicis nerve-muscle (3-10 microg/ml) and mouse phrenic nerve-diaphragm (10 microg/ml) preparations. A. praelongus venom was significantly less neurotoxic than A. antarcticus venom but was not significantly different from A. pyrrhus venom. In the biventer muscle, all three venoms (3-10 microg/ml) abolished responses to exogenous ACh (1 mM) and carbachol (20 microM), but not KCl (40 mM), indicating activity at post-synaptic nicotinic receptors. All venoms (30 microg/ml) failed to produce significant inhibition of direct twitches (0.1 Hz, 2.0 ms, supramaximal voltage) in the chick biventer cervicis nerve-muscle preparation. However, A. praelongus (30 microg/ml) venom initiated a significant direct contracture of muscle, indicative of some myotoxic activity. The prior (10 min) administration of death adder antivenom (1 unit/ml), which is raised against A. antarcticus venom, markedly attenuated the twitch blockade produced by all venoms (10 microg/ml). Administration of antivenom (1.5 units/ml) at t(90) markedly reversed, over a period of 4 h, the inhibition of twitches produced by A. praelongus (3 microg/ml, 72+/-6% recovery) and A. pyrrhus (3 microg/ml, 51+/-9% recovery) but was less effective against A. antarcticus venom (3 microg/ml, 22+/-7% recovery). These results suggest that all three venoms contain postsynaptic neurotoxins. Death adder antivenom displayed differing efficacy against the in vitro neurotoxicity of the three venoms.
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Affiliation(s)
- J C Wickramaratna
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Vic. 3800, Australia
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Tyler MI, Retson-Yip KV, Gibson MK, Barnett D, Howe E, Stöcklin R, Turnbull RK, Kuchel T, Mirtschin P. Isolation and amino acid sequence of a new long-chain neurotoxin with two chromatographic isoforms (Aa el and Ae e2) from the venom of the Australian death adder (Acanthophis antarcticus). Toxicon 1997; 35:555-62. [PMID: 9133710 DOI: 10.1016/s0041-0101(96)00159-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The amino acid sequence of a previously undescribed toxin from Australian death adder venom (Acanthophis antarcticus) has been elucidated. It appears to exist in two forms which are separated by reverse-phase high-performance liquid chromatography, but which have the same sequence and mol. wt. It has 79 amino acid residues and is therefore longer than other long postsynaptic neurotoxins. It shows homology with the conserved regions of the other long postsynaptic neurotoxins except for three unique substitutions of conserved residues, which are Arg-29 instead of Trp or Phe, Leu-33 instead of Arg and Thr-43 instead of Ala.
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Affiliation(s)
- M I Tyler
- Deakin Research Ltd, c/-CSIRO, Division of Food Science and Technology, NSW, Australia
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Flachsenberger W, Mirtschin P. Anticholinesterases as antidotes to envenomation of rats by the death adder (Acanthophis antarcticus). Toxicon 1994; 32:35-9. [PMID: 9237335 DOI: 10.1016/0041-0101(94)90019-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to find an antidote against death adder envenomation that can be used in cases of emergency, when antivenoms are not readily available (Papua New Guinea and the Australian outback). Such an antidote should allow bite victims to survive until established treatment is possible. Death adder venom is thought to act postsynaptically at the neuromuscular junction to reduce responses to acetylcholine. This causes severe flaccid paralysis and finally death, which is usually a consequence of respiratory failure. Albino Wistar rats were injected with a lethal dose of crude death adder venom. At the onset of severe envenomation symptoms, anticholinesterases (neostigmine and edrophonium) in conjunction with atropine sulfate were administered. At the minimum lethal dose (0.15 mg/kg) all animals survived as a result of the anticholinesterase treatment. The expected survival time of animals subjected to higher venom doses was significantly extended. These results indicate that death adder bite victims may gain valuable time, if anticholinesterases can be administered during the initial critical stage of envenomation.
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Affiliation(s)
- W Flachsenberger
- Department of Physiology, University of Adelaide, South Australia
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Tan NH, Ponnudurai G. A comparative study of the biological properties of Australian elapid venoms. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1990; 97:99-106. [PMID: 1981349 DOI: 10.1016/0742-8413(90)90178-c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
1. The hemorrhagic, procoagulant, anticoagulant, protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, arginine ester hydrolase, phospholipase A, 5'-nucleotidase and hyaluronidase activities of 39 samples of venoms from 13 species (15 taxa) of Australian elapids were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. The results indicate that Australian elapid venoms can be divided into two groups: procoagulant Australian venoms (including N. scutatus, N. ater, O. scutellatus, O. microlepidotus, P. porphyriacus, T. carinatus, H. stephensii and P. textilis) and non-procoagulant Australian venoms (including A. superbus, P. colletti, P. australis, P. guttatus and A. antarcticus). 3. The non-procoagulant Australian venoms exhibited biological properties similar to other elapid venoms, while the procoagulant Australian venoms exhibited some properties characteristic of viperid venoms. 4. The data show that information on venom biological properties can be used for differentiation of many species of Australian elapids. 5. Particularly useful for this purpose are the hyaluronidase, alkaline phosphomonoesterase, acetylcholinesterase, and the procoagulant activities and the Sephadex G-75 gel filtration patterns of the venoms.
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Affiliation(s)
- N H Tan
- Department of Biochemistry, University of Malaya, Kuala Lumpur
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Sheumack DD, Spence I, Tyler MI, Howden ME. The complete amino acid sequence of a post-synaptic neurotoxin isolated from the venom of the Australian death adder snake Acanthophis antarcticus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1990; 95:45-50. [PMID: 2158871 DOI: 10.1016/0305-0491(90)90246-p] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. A lethal neurotoxin (acanthophin d) was isolated from the venom of the Australian death adder snake Acanthophis antarcticus. 2. Acanthophin d consisted of a single polypeptide chain of 74 amino acid residues cross-linked by five disulphide bridges. 3. The results of neurophysiological experiments on murine phrenic nerve hemi-diaphragm preparations were consistent with irreversible post-synaptic blockage of neuromuscular transmission by acanthophin d.
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Affiliation(s)
- D D Sheumack
- School of Chemistry, Macquarie University, NSW, Australia
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Hudson BJ. Positive response to edrophonium in death adder (Acanthophis antarcticus) envenomation. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1988; 18:792-4. [PMID: 3242468 DOI: 10.1111/j.1445-5994.1988.tb00183.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A 20-year-old Papua New Guinean male developed neuromuscular paralysis following a bite by a death adder (Acanthophis antarcticus). Ptosis persisted despite otherwise effective anti-venom therapy. The ptosis clinically resembled myasthenia gravis and improved after intravenous edrophonium. The role of anticholinesterase drugs in snake bite management is discussed.
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Affiliation(s)
- B J Hudson
- Madang General Hospital, Madang, Papua, New Guinea
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Kim HS, Tamiya N. Isolation, properties and amino acid sequence of a long-chain neurotoxin, Acanthophis antarcticus b, from the venom of an Australian snake (the common death adder, Acanthophis antarcticus). Biochem J 1981; 193:899-906. [PMID: 7305964 PMCID: PMC1162683 DOI: 10.1042/bj1930899] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The venom of an Australian elapid snake, the common death adder (Acanthophis antarcticus), was chromatographed on a CM-cellulose CM52 column. One of the neurotoxic components, Acanthophis antarcticus b (toxin Aa b) was isolated in about 9.4% (A280) yield. The complete amino acid sequence of toxin Aa b was elucidated. Toxin Aa b is composed of 73 amino acid residues, with ten half-cystine residues, and has a formula weight of 8135. Toxin Aa b has no histidine or methionine residue in its sequence. The amino acid sequence of toxin Aa b is homologous with those of other neurotoxins with known sequences, although it is novel in having a valine residue at its N-terminus and an arginine residue at position-23, where a lysine residue is found in almost all the so-far-known neurotoxins. Irrespective of the latter replacement, the toxin Aa b is fully active, with an LD50 value (in mice) of 0.13 microgram/g body weight on intramuscular injection.
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