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Messadi E. Snake Venom Components as Therapeutic Drugs in Ischemic Heart Disease. Biomolecules 2023; 13:1539. [PMID: 37892221 PMCID: PMC10605524 DOI: 10.3390/biom13101539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/18/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
Ischemic heart disease (IHD), especially myocardial infarction (MI), is a leading cause of death worldwide. Although coronary reperfusion is the most straightforward treatment for limiting the MI size, it has nevertheless been shown to exacerbate ischemic myocardial injury. Therefore, identifying and developing therapeutic strategies to treat IHD is a major medical challenge. Snake venoms contain biologically active proteins and peptides that are of major interest for pharmacological applications in the cardiovascular system (CVS). This has led to their use for the development and design of new drugs, such as the first-in-class angiotensin-converting enzyme inhibitor captopril, developed from a peptide present in Bothrops jararaca snake venom. This review discusses the potential usefulness of snake venom toxins for developing effective treatments against IHD and related diseases such as hypertension and atherosclerosis. It describes their biological effects at the molecular scale, their mechanisms of action according to their different pharmacological properties, as well as their subsequent molecular pathways and therapeutic targets. The molecules reported here have either been approved for human medical use and are currently available on the drug market or are still in the clinical or preclinical developmental stages. The information summarized here may be useful in providing insights into the development of future snake venom-derived drugs.
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Affiliation(s)
- Erij Messadi
- Plateforme de Physiologie et Physiopathologie Cardiovasculaires (P2C), Laboratoire des Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, Tunis 1068, Tunisia
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2
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Hanf ZR, Chavez AS. A Comprehensive Multi-Omic Approach Reveals a Relatively Simple Venom in a Diet Generalist, the Northern Short-Tailed Shrew, Blarina brevicauda. Genome Biol Evol 2020; 12:1148-1166. [PMID: 32520994 PMCID: PMC7486961 DOI: 10.1093/gbe/evaa115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2020] [Indexed: 12/15/2022] Open
Abstract
Animals that use venom to feed on a wide diversity of prey may evolve a complex mixture of toxins to target a variety of physiological processes and prey-defense mechanisms. Blarina brevicauda, the northern short-tailed shrew, is one of few venomous mammals, and is also known to eat evolutionarily divergent prey. Despite their complex diet, earlier proteomic and transcriptomic studies of this shrew's venom have only identified two venom proteins. Here, we investigated with comprehensive molecular approaches whether B. brevicauda venom is more complex than previously understood. We generated de novo assemblies of a B. brevicauda genome and submaxillary-gland transcriptome, as well as sequenced the salivary proteome. Our findings show that B. brevicauda's venom composition is simple relative to their broad diet and is likely limited to seven proteins from six gene families. Additionally, we explored expression levels and rate of evolution of these venom genes and the origins of key duplications that led to toxin neofunctionalization. We also found three proteins that may be involved in endogenous self-defense. The possible synergism of the toxins suggests that vertebrate prey may be the main target of the venom. Further functional assays for all venom proteins on both vertebrate and invertebrate prey would provide further insight into the ecological relevance of venom in this species.
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Affiliation(s)
- Zachery R Hanf
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
| | - Andreas S Chavez
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
- Translational Data Analytics Institute, The Ohio State University
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3
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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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4
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Ismail M, Al-Ahaidib MS, Abdoon N, Abd-Elsalam MA. Preparation of a novel antivenom against Atractaspis and Walterinnesia venoms. Toxicon 2007; 49:8-18. [PMID: 17097125 DOI: 10.1016/j.toxicon.2006.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The two deadly snakes, Walterinnesia aegyptia (black desert cobra) and Atractaspis microlepidota (mole viper) share a common habitat in the central, eastern and western provinces of Saudi Arabia. Bites by either snake were characterized by rapid death, sometimes before reaching any medical facility. Confusing reports of "a black snake bite" are frequently found. The NAVPC had succeeded in preparing a highly effective antivenom against W. aegyptia venom which is now available in the market, but no antivenom against Atractaspis venom is found worldwide. This is probably because of the low molecular weight of sarafotoxins in the venom and hence their poor antigenic properties. At the NAVPC, sarafotoxins were separated by sequential gel filtration of A. microlepidota venom, while toxin T(III) of W. aegyptia venom obtained by cation exchange chromatography and gel filtration. Conjugation of the two toxins was carried out using glutaraldehyde in a two-step procedure followed by exhaustive dialysis. The conjugate was utilized to hyperimmunize 3-years old horses for 10 months, applying a low-dosage protocol and immunostimulants; the crude venoms of both snakes being added during the last 2 months. The F(ab')2 fraction of the antivenom was obtained by pH-guided salt precipitation, enzyme digestion and tangential desalting and filtration. The bivalent antivenom obtained protected mice and rats against the lethal effects of both venoms and rescued the rats challenged with lethal doses of the venoms in recovery experiments. It also neutralized the haemorrhagic, necrotizing and the cardiotoxic effects of A. microlepidota venom and the neuromuscular blocking effect of W. aegyptia venom. The antivenom offers a good rescue potential to those who are bitten by "a black snake" in Saudi Arabia.
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Affiliation(s)
- M Ismail
- 6 October University, Cairo, Egypt
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5
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Hayashi MAF, Ligny-Lemaire C, Wollberg Z, Wery M, Galat A, Ogawa T, Muller BH, Lamthanh H, Doljansky Y, Bdolah A, Stöcklin R, Ducancel F. Long-sarafotoxins: characterization of a new family of endothelin-like peptides. Peptides 2004; 25:1243-51. [PMID: 15350691 DOI: 10.1016/j.peptides.2004.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 05/13/2004] [Accepted: 05/13/2004] [Indexed: 12/31/2022]
Abstract
Sarafotoxins (SRTXs) constitute a family of vasoactive peptides that were initially isolated from the venom of Atractaspis engaddensis, and that are structurally and functionally related to endothelins (ETs). Analysis of the venom of Atractaspis microlepidota microlepidota revealed several new SRTX molecules manifesting some new structural and functional characteristics. These novel SRTXs are longer by three amino acids than the previously described SRTXs, and are designated here "long-SRTXs". Six isoforms, derived from new poly-cistronic precursors, have been identified so far in the venom of this snake. One of these isoforms, designated SRTX-m, was chemically synthesized and its biological properties were studied. Our results show that SRTX-m induces toxicity in mice, mostly due to vasoconstriction, and also that it has a lower toxicity and potency than the more potent SRTX described up to now: sarafotoxin-b (SRTX-b) from A. engaddensis.
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Affiliation(s)
- Mirian A F Hayashi
- Biochemical and Biophysical Laboratory, Instituto Butantan, SP 05503-900 Sao Paulo, Brazil
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6
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Ducancel F, Wery M, Hayashi MA, Muller BH, Stöcklin R, Ménez A. Les sarafotoxines de venins de serpent. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0924-4204(99)80033-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Bdolah A, Kochva E, Ovadia M, Kinamon S, Wollberg Z. Resistance of the Egyptian mongoose to sarafotoxins. Toxicon 1997; 35:1251-61. [PMID: 9278974 DOI: 10.1016/s0041-0101(97)00019-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Egyptian mongoose (Herpestes ichneumon) is known for its resistance to viperid and elapid venoms. The current work demonstrates that it is also resistant to the venom of Atractaspis and its most toxic component, sarafotoxin-b. Intravenous administration of this toxin, at a dose of about 13 times LD100 for mice, resulted in disturbance in electrocardiograms in the mongoose, which returned to normal after several hours. Sarafotoxin-b failed to induce contraction of mongoose aortal preparations. Endothelin-1, which was demonstrated in tissue extracts of the mongoose by immunological methods, induced contraction of the isolated mongoose aorta. This contraction, however, was greatly reduced when endothelin-1 was applied on top of sarafotoxin-b. Binding studies revealed endothelin/sarafotoxin-specific binding sites in brain and cardiovascular preparations of the mongoose. It is suggested that some structural features of endothelin/sarafotoxin receptors in the mongoose enable them to differentiate between the two peptides.
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Affiliation(s)
- A Bdolah
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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8
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Lamthanh H, Deprun C, Le Beyec YL. Plasma desorption mass spectrometry of two synthetic sarafotoxins: side reactions and characterization of the intermediates. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 1994; 8:971-975. [PMID: 7696705 DOI: 10.1002/rcm.1290081213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sarafotoxins (SRTXs) form a family of toxic and potent vasoconstrictor peptides of 21 amino acids and two disulfide bonds. They are present in the venom of the burrowing asp Atractaspis engaddensis. We have made two derivatives of the amino acid sequence of SRTX-b, one of the most potent isotoxins, in the solid phase. First, we replaced Ser2 by Thr, to investigate whether, as previously postulated, this change is responsible for the weak activities of SRTXs c and d. Secondly, we replaced Ser2, Asp18 and Val19 respectively by Thr, Gly and Ile, with a view to generating SRTX-e whose amino acid sequence was deduced from cDNA. Solid-phase peptide synthesis (SPPS) was performed according to the tert-butyloxycarbonyl strategy and the disulfides were paired sequentially using a selective chemistry. The disulfide 1-15 was formed by oxidation of cysteines1,15 with ferricyanide, whereas disulfide 3-11 was made by iodine oxidation of Acm-blocked cysteines3,11. By plasma desorption mass spectrometry (PDMS), we monitored all possible side reactions that occurred during the synthesis. We thus observed a benzyl shift in mass spectra when aspartic and glutamic acid side chains were protected by a benzyl group during the SPPS. This could be circumvented by using instead, a cyclohexyl protecting group. We also noted the oxidation of the methionine and the tryptophan side chain (formation of methionine sulfoxide and oxindole ring of tryptophan) to a small extent during the cleavage peptide/solid phase oxidation of the methionine side chain during the formation of the disulfide 1-15 by ferricyanide.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H Lamthanh
- CEA, Département d'Ingénierie et d'Etudes des Protéines (DIEP), C. E. Saclay, Gif sur Yvette, France
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9
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Lamthanh H, Bdolah A, Creminon C, Grassi J, Menez A, Wollberg Z, Kochva E. Biological activities of [Thr2]sarafotoxin-b, a synthetic analogue of sarafotoxin-b. Toxicon 1994; 32:1105-14. [PMID: 7801346 DOI: 10.1016/0041-0101(94)90394-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The 21 amino acid sarafotoxins (SRTX) c and d/e as well as endothelin-3 (ET-3) are known to be less toxic and weaker pharmacologically than the other isopeptides SRTX-a, SRTX-b and ET-1. Since SRTX-c, SRTX-d/e and ET-3 possess a Thr instead of a Ser at position 2, we investigated the possibility that this mutation could be responsible for the observed biological differences. Here we show that the synthetic [Thr2]SRTX-b has indeed a lower vasoconstriction efficacy (approximately 35%) in the rabbit aorta, but it is nearly as potent as SRTX-b in toxicity tests and in influencing contraction of the rat uterus. Using monoclonal antibodies directed against the structurally related endothelin-1, we also show that the antigenicity of the analogue is comparable to that of SRTX-b, suggesting that the overall structure of the two peptides is similar, despite the substitution at position 2. We suggest that the Thr2 substitution contributes to the lower activity of the 'weak' peptides in some systems; however, additional substitutions found in the 'weak' peptides of the ET/SRTX family most probably contribute to their low pharmacological activity.
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Affiliation(s)
- H Lamthanh
- Departement d'Ingenierie, Etudes des Proteines, DSV, CEA, CE, Gif sur Yvette, France
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10
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Hay DW, Luttmann MA, Hubbard WC, Undem BJ. Endothelin receptor subtypes in human and guinea-pig pulmonary tissues. Br J Pharmacol 1993; 110:1175-83. [PMID: 8298806 PMCID: PMC2175787 DOI: 10.1111/j.1476-5381.1993.tb13938.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. In this study the endothelin (ET) receptor subtypes mediating contractions produced by ET-1 in human and guinea-pig pulmonary tissues were investigated. In addition the receptor responsible for ET-1-induced prostanoid release in human bronchus was determined. 2. In human bronchus and human pulmonary artery ET-1 (0.1 nM-0.3 microM) was a potent and effective contractile agent (pD2 = 7.58 +/- 0.15, n = 6, and 8.48 +/- 0.11, n = 7, respectively). BQ-123 (1-10 microM), a potent and selective ETA receptor antagonist, potently antagonized ET-1-induced contraction in human pulmonary artery (pKB = 6.8 with 1 microM BQ-123, n = 7) but had no effect in human bronchus (n = 6). 3. Sarafotoxin S6c (0.1 nM-0.1 microM), the ETB-selective agonist, did not contract human pulmonary artery (n = 5), but potently and effectively contracted human bronchus: pD2 = 8.41 +/- 0.17, maximum response = 74.4 +/- 3.1% of 10 microM carbachol; n = 5. BQ-123 (1-10 microM) did not antagonize sarafotoxin S6c-induced contraction in human bronchus (n = 5). 4. ET-1 potently contracted guinea-pig trachea, bronchus, pulmonary artery and aorta (pD2 = 8.15 +/- 0.14, 7.72 +/- 0.12, 8.52 +/- 0.12, and 8.18 +/- 0.12, respectively, n = 6-14). BQ-123 (0.1-10 microM)antagonized ET-1-induced contractions in guinea-pig pulmonary artery (pKB = 6.7 with 1 microM BQ-123,n = 6), aorta (pKB = 7.1 with 1 microM BQ-123, n = 6) and trachea (pKB = 6.2 with 1 microM BQ-123, n = 6) butwas without marked effect in bronchus (n = 4). In contrast, sarafotoxin S6c (0.1 nM-0.l microM) did not contract guinea-pig aorta (n = 4) or guinea-pig pulmonary artery (n = 6) but potently and effectively contracted guinea-pig bronchus: pD2= 8.55 +/- 0. 1; maximum contraction = 63.6 +/0 3.1% of 10 microM carbachol,n = 4. Sarafotoxin S6c (0.1 nM-0. 1 microM) was a much less effective agonist in guinea-pig trachea:maximum contraction = 13.9 +/- 2.5% of 10 JM carbachol, n = 4; P< 0.0001, compared to bronchus.Contractions produced by sarafotoxin S6c in guinea-pig bronchus or trachea were unaffected by BQ-123(IO microM, n=4).5. Significant differences were observed in the efficacy, relative to carbachol, but not the potency of sarafotoxin S6c in guinea-pig airways, with a much greater maximum contractile response in bronchus(69.6 +/- 2.4% of 10 microM carbachol, n = 6) or lower region of the trachea (48.5 +/- 5.9% of 10 microM carbachol,n = 6) than in the middle region of the trachea (14.4 +/- 4.0% of 10 microM carbachol, n = 6) or the upper region of the trachea (19.3 +/- 2.7% of 10 microM carbachol, n = 6). There were minimal regional differences in either ET-1-induced contraction or the potency of BQ-123 (3 microM) for inhibition of responses to ET-1 in guinea-pig airways.6. Release of various prostanoids in human bronchus induced by ET-1 (0.3 microM) was essentially abolished with 10 IM BQ-123.7. These data provide evidence that distinct ET receptors mediate ET-1-induced contraction in human pulmonary artery, guinea-pig pulmonary artery and guinea-pig aorta (ETA subtype) compared with human bronchus and guinea-pig bronchus (non-ETA, perhaps ETB subtype). Contractions to ET-1 in guinea-pig trachea appear to involve both ETA and non-ETA (ETB?) receptor subtypes. Furthermore,regional differences appear to exist in the relative distribution of ET receptor subtypes in guinea-pig airways. In human bronchus ET-1-induced prostanoid release, unlike the contractile response, appears to be mediated via ETA receptor activation.
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MESH Headings
- Animals
- Aorta/drug effects
- Aorta/physiology
- Aorta/ultrastructure
- Bronchi/drug effects
- Bronchi/physiology
- Bronchi/ultrastructure
- Endothelins/pharmacology
- Guinea Pigs
- Humans
- In Vitro Techniques
- Lung/drug effects
- Lung/physiology
- Lung/ultrastructure
- Male
- Models, Biological
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Muscle, Smooth/ultrastructure
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Muscle, Smooth, Vascular/ultrastructure
- Peptides, Cyclic/pharmacology
- Prostaglandins/metabolism
- Pulmonary Artery/drug effects
- Pulmonary Artery/physiology
- Pulmonary Artery/ultrastructure
- Receptors, Endothelin/classification
- Receptors, Endothelin/drug effects
- Receptors, Endothelin/physiology
- Trachea/drug effects
- Trachea/physiology
- Trachea/ultrastructure
- Viper Venoms/pharmacology
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Affiliation(s)
- D W Hay
- Department of Inflammation & Respiratory Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406
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11
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Abstract
The venom of the burrowing asp Atractaspis engaddensis contains several 21 amino acid residue peptides known as sarafotoxins. The sarafotoxins are homologous to the mammalian endothelin family, and they have similar biological activities. This review covers recent advances in the study of the chemical and biological properties of the sarafotoxins and endothelins.
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Affiliation(s)
- E Kochva
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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12
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Becker A, Dowdle EB, Hechler U, Kauser K, Donner P, Schleuning WD. Bibrotoxin, a novel member of the endothelin/sarafotoxin peptide family, from the venom of the burrowing asp Atractaspis bibroni. FEBS Lett 1993; 315:100-3. [PMID: 8416802 DOI: 10.1016/0014-5793(93)81142-m] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A new member of the endothelin/sarafotoxin family of vasoconstrictor peptides, bibrotoxin (BTX), was isolated from the venom of the burrowing asp Atractaspis bibroni by reversed-phase FPLC. The amino acid sequence of BTX differs from SRTX-b in the substitution Ala4 instead of Lys4, which suggests that it represents the peptide isoform of Atractaspis bibroni corresponding to SRTX-b. BTX competed for [125I]ET-1 binding to human ETB-type receptor with a Ki of 3.2 x 10(-9) M compared to 4.2 x 10(-9) M for SRTX-b. In rat thorax aorta BTX induced vasoconstrictions with a threshold concentration of 3 x 10(-8) M compared to 1 x 10(-9) for ET-1.
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Affiliation(s)
- A Becker
- Research Laboratories of Schering AG, Berlin, Germany
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13
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Affiliation(s)
- T Masaki
- Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan
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14
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Zigdon-Arad T, Bdolah A, Kochva E, Wollberg Z. Activity of sarafotoxin/endothelin peptides in the heart and brain of lower vertebrates. Toxicon 1992; 30:439-48. [PMID: 1626325 DOI: 10.1016/0041-0101(92)90540-l] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of sarafotoxin-b (SRTX-b) and endothelin-1 (ET-1) were tested in the fish tilapia (Ore niloticus x O. aureus hybrids) and torpedo (Torpedo ocellata), the toad (Bufo viridis), the agama lizard (Agama stellio) and water snake (Natrix tessellata). In isolated heart preparations of the fish and agama, peptide doses of 0.05-0.5 micrograms/ml induced positive inotropic effects, reduction of the contraction rate and arrhythmia, leading to cardiac arrest. In the toad, a negative inotropic effect and a reduction of the contraction rate were observed, whereas the water snake was hardly affected by either SRTX-b or ET-1. In the agama, an i.v. injection of 15 micrograms of SRTX-b caused changes in the ECG, culminating in A-V block that led to cardiac arrest, while in the toad an injection of 45 micrograms induced only transient disturbances in the ECG. Binding studies with 125I-SRTX-b revealed specific binding sites for SRTX-b and ET-1 in the heart and brain preparations of fish (tilapia and torpedo) and agama, whereas no specific binding could be demonstrated in the toad or in the snake. These results suggest that most vertebrates tested are sensitive to SRTX/ET, while the snake may possess receptors that are of a different structure.
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Affiliation(s)
- T Zigdon-Arad
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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15
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Wollberg Z, Bdolah A, Galron R, Sokolovsky M, Kochva E. Contractile effects and binding properties of endothelins/sarafotoxins in the guinea pig ileum. Eur J Pharmacol 1991; 198:31-6. [PMID: 1915577 DOI: 10.1016/0014-2999(91)90558-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Seven of the eight known isopeptides of the endothelin/sarafotoxin (ET/SRTX) family were tested on the isolated guinea pig ileum and found to cause a concentration-dependent increase in basal tone. The rate or the amplitude of the spontaneous rhythmic contractions of the ileal smooth muscle were essentially not affected by any of the peptides. The maximum contraction elicited by vasoactive intestinal contractor (VIC) was slightly stronger than that induced by endothelin-1 (ET-1) or sarafotoxin-b (SRTX-b), and significantly stronger than the maximal contractions elicited by sarafotoxin-a (SRTX-a), sarafotoxin-c (SRTX-c), or endothelin-3 (ET-3). Sarafotoxin-d (SRTX-d) caused, essentially, no contraction but a rather marked relaxation. The potencies of the various peptides to induce the increase in tension, in terms of EC50 values (cumulative effective concentrations that induce half-maximum response), ranged between 6 and 95 nM depending on the peptide. VIC, ET-1, SRTX-b and SRTX-a had similar potencies and were significantly more potent than SRTX-c and ET-3. A high concentration of SRTX-b elicited no additional response when applied to the organ bath after one of the other peptides had shown a maximal effect. Binding experiments with ileal membranes revealed similar binding properties for the various peptides. Competition with iodinated SRTX-b showed no meaningful differences between the various peptides. It is concluded that all the ET/SRTX peptides compete for the same receptor subtype in the ileum. In terms of efficacy, VIC can be considered as a full agonist of this receptor, SRTX-d is probably an antagonist, while all the other peptides behave as partial agonists.
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Affiliation(s)
- Z Wollberg
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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16
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Landan G, Bdolah A, Wollberg Z, Kochva E, Graur D. Evolution of the sarafotoxin/endothelin superfamily of proteins. Toxicon 1991; 29:237-44. [PMID: 2048141 DOI: 10.1016/0041-0101(91)90108-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sixteen protein and nucleic acid sequences from the vasoconstrictor sarafotoxin/endothelin/endothelin-like superfamily of peptides were studied, and the evolutionary relationships between the sarafotoxin and endothelin gene families as well as the phylogenetic topology within each gene family and the three endothelin subfamilies was reconstructed. The endothelin gene family has diverged from an ancestral gene that has experienced an exon duplication event followed by two gene duplication events. The sarafotoxins' lineage diverged from the ancestral gene prior to the first endothelin gene duplication event. Analysis of the resulting phylogenetic trees revealed that in several lineages, the peptides have independently accumulated identical replacements in position 2, therefore supporting the hypothesis that residue 2 is crucial to their activity.
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Affiliation(s)
- G Landan
- Interdisciplinary Program for Fostering Excellence, Tel Aviv University, Ramat Aviv, Israel
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Skolovsky M, Galron R, Kloog Y, Bdolah A, Indig FE, Blumberg S, Fleminger G. Endothelins are more sensitive than sarafotoxins to neutral endopeptidase: possible physiological significance. Proc Natl Acad Sci U S A 1990; 87:4702-6. [PMID: 2191299 PMCID: PMC54185 DOI: 10.1073/pnas.87.12.4702] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Incubation of endothelins (ETs) with bovine kidney neutral endopeptidase (NEP) resulted in a selective two-step degradation with loss of biochemical activity. The Km of the enzyme indicated high-affinity binding, and hydrolysis was completely inhibited by phosphoramidon. The first step was nicking of the Ser5-Leu6 bond, followed by cleavage at the amino side of Ile19. The nicked peptide exhibited biochemical activities comparable to those of the intact peptide--i.e., binding to the ET receptor, induction of inositol phospholipid hydrolysis, and toxicity. The twice-cleaved product was inactive. The sarafotoxins (SRTXs) were more resistant than the ETs to NEP: for example, the half-time for ET-1 was approximately 1 hr, while it was approximately 4 hr for SRTX-b and even higher for SRTX-c. These in vitro findings may indicate a regulatory role of NEP (or similar enzymes) in the physiological inactivation of ETs. They might also help to explain why under certain physiological conditions ETs may be less toxic than SRTXs.
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Affiliation(s)
- M Skolovsky
- Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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18
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Vigne P, Marsault R, Breittmayer JP, Frelin C. Endothelin stimulates phosphatidylinositol hydrolysis and DNA synthesis in brain capillary endothelial cells. Biochem J 1990; 266:415-20. [PMID: 2156495 PMCID: PMC1131147 DOI: 10.1042/bj2660415] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Endothelin-1 (ET-1) is a novel vasoconstricting and cardiotonic peptide that is synthesized by the vascular endothelium. Bovine aortic endothelial cells which secrete ET in vitro lack membrane receptor sites for the peptide. Endothelial cells from rat brain microvessels that do not secrete ET in vitro express large amounts of high-affinity receptors for 125I-labelled ET-1 (Kd 0.8 nM). The ET receptor is recognized by sarafotoxin S6b and the different ET peptides with the following order of potency: ET-1 (Kd 0.5 nM) approximately equal to ET-2 (Kd 0.7 nM) greater than sarafotoxin S6b (Kd 27 nM) greater than ET-3 (Kd 450 nM). This structure-activity relationship is different from those found in vascular smooth muscle cells, renal cells and cardiac cells. ET-1 stimulates DNA synthesis in brain capillary endothelial cells. It is more potent than basic fibroblast growth factor. The action of ET on endothelial cells from microvessels involves phosphatidylinositol hydrolysis and intracellular Ca2+ mobilization. These observations suggest that brain endothelial cells might be an important target for ET.
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Affiliation(s)
- P Vigne
- Institut de Pharmacologie Moléculaire et Cellulaire, UPR 411 CNRS, Valbonne, France
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Lin WW, Chen YM, Lee SY, Nishio H, Kimura T, Sakakibara S, Lee CY. Cardiovascular effects of two disulfide analogues of sarafotoxin S6b. Toxicon 1990; 28:911-23. [PMID: 2080517 DOI: 10.1016/0041-0101(90)90021-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sarafotoxin S6b (STX-b), a peptide toxin isolated from the venom of the Israeli burrowing asp, Atractaspis engaddensis, consists of 21 amino acid residues with four cysteines at positions 1,3,11 and 15. In the present study, we compared the cardiovascular effects of two synthetic STX-b analogues with different disulfide bridge locations, i.e. STX-b type A (1-15, 3-11) and STX-b type B (1-11, 3-15). At doses of 0.3-3 nmoles/kg (i.v.), type A produced a sustained pressor effect with transient increase in pulse pressure. However, at 5 nmoles/kg, it produced a transient increase followed by decrease in blood pressure, heart rate and respiratory rate within 30 sec and 12 out of 13 mice died within 10 min. Various kinds of ECG changes, suggestive of myocardial ischemia and hyperkalemia, were observed. Type A also caused a significant increase in the plasma levels of K+, lactate dehydrogenase, creatine phosphokinase, inorganic phosphate and glucose. By contrast, type B did not kill any mouse at doses up to 50 nmoles/kg. In the rat aorta, type A caused a potent vasoconstriction which was dependent on extracellular Ca2+ and was partially inhibited by verapamil and H-7, a protein kinase C inhibitor. In the rat Langendorff heart preparation, type A produced coronary vasospasm with potency about 100 times higher than that of type B. A similar potency ratio was observed for the positive inotropic effect in rat atria. These results indicate that the location of disulfide bridges in sarafotoxin S6b markedly influences the pharmacological potency and the natural sarafotoxin S6b should be type A with the disulfide bridge locations at positions 1-15 and 3-11.
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Affiliation(s)
- W W Lin
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, R.O.C
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Bdolah A, Wollberg Z, Fleminger G, Kochva E. SRTX-d, a new native peptide of the endothelin/sarafotoxin family. FEBS Lett 1989; 256:1-3. [PMID: 2509240 DOI: 10.1016/0014-5793(89)81706-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The primary structure of a new sarafotoxin, SRTX-d, from the venom of Atractaspis engaddensis is described. SRTX-d differs from SRTX-b in two substitutions: Ile19 instead of Val and Thr2 instead of Ser. The toxicity of SRTX-d and its vasoconstriction potency are very low in comparison to SRTX-a and SRTX-b, whereas its IC50 for 125I-SRTX-b binding is similar to that of SRTX-b. It is suggested that the Thr to Ser substitution, which is shared by two additional weak members of the endothelin/sarafotoxin family, SRTX-c and ET-3, affects the biological activity of SRTX-d as well.
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Affiliation(s)
- A Bdolah
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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