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Jafari Z, Bandehpour M, Gheflat S, Mohammadi N, Kazemi B. Cloning, Expression and Purification of Full-length Recombinant Ecarin and Comparing Its Expression and Function with Its Truncated Form. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH 2022; 21:e123791. [PMID: 35765508 PMCID: PMC9191215 DOI: 10.5812/ijpr.123791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 11/16/2022]
Abstract
: Ecarin is a metalloproteinase found in snake venom (SVMP) with an important role in coagulation and control of hemostasis. It can specifically produce active-thrombin from prethrombin-2 and does not differentiate between normal and abnormal prothrombin. It is used in diagnostic tests and to evaluate the treatment process of many diseases. There are many drawbacks associated with separating these compounds from snake venom. Therefore, in this study, full-length recombinant Ecarin (r-Ecarin) was cloned, expressed, and purified in eukaryotic host cells. To determine the most effective form of the enzyme, r-Ecarin was compared with the recombinant truncated form, which has only the metalloprotease domain of the protein (r-Ecamet) in terms of function and expression. Briefly, A DNA construct composed of sequence-encoding Ecarin was designed and cloned into pCAGGS expression vector and, subsequently, expressed in Chinese Hamster Ovary (CHO) cells. To identify the enzymatic activity of expressed protein, a bioactivity assay was performed. Blood coagulation time and expression levels of r-Ecarin and r-Ecamet proteins were compared. Also, a histopathological assessment was carried out on the liver of mice treated with these proteins. Comparison of r-Ecarin and r-Ecamet expression pattern demonstrated that full-length Ecarin expression has at least 2-fold higher expression in eukaryotic cells. Determination of r-Ecarin function proved that this protein is capable of prothrombin cleavage and producing thrombin. Comparison of PT test results between the r-Ecarin and r-Ecamet showed that there is a significant difference in the activity of the two enzymes and the full-length protein coagulates the blood in less time.
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Affiliation(s)
- Zohreh Jafari
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mojgan Bandehpour
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shivasadat Gheflat
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasrin Mohammadi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Bahram Kazemi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Corresponding Author: Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Overview and Practical Application of Coagulation Assays in Managing Anticoagulation with Direct Oral Anticoagulants (DOACs). ACTA ACUST UNITED AC 2020. [DOI: 10.1007/s40495-020-00232-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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3
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Johnson LA, de Jersey J, Masci PP, Zhao KN, Bennett NC, Dimeski G, Grant M, Lavin MF. Progress Curve Analysis of the one stage chromogenic assay for ecarin. Anal Biochem 2020; 608:113907. [PMID: 32814078 DOI: 10.1016/j.ab.2020.113907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 11/26/2022]
Abstract
Snake venom prothrombin activators such as Ecarin are readily assayed by continuous spectrophotometric monitoring of p-nitroaniline production in a one step assay containing prothrombin and a p-nitroanilide peptide substrate for thrombin. The coupled reactions result in accelerating p-nitroaniline (pNA) production over the course of the assay giving non-linear progress curves, from which initial velocities are not readily obtained. Most studies therefore resort to approximate estimates of activity, based on the absorbance reached at an arbitrary time. A simple kinetic analysis of the coupled reactions shows that the early points of such curves should be fitted by second order polynomials, representing the accelerating reaction rate in μmol pNA/min/min. The first derivative of the polynomial then gives the increasing velocity of pNA production in μmol pNA/min over the time course of the assay. We demonstrate here that, with the substrate S2238, these rates can be converted to absolute thrombin concentrations using the Michaelis-Menten equation, substituted with values for kcat and Km. These thrombin concentrations increase linearly over the time course of the assay allowing the activity to be expressed in units, defined as μmol product/min, most commonly used to report enzyme activity.
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Affiliation(s)
- Lambro A Johnson
- Centre for Kidney Disease Research-Venomics Research, School of Medicine, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia.
| | - John de Jersey
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4078, Australia
| | - Paul P Masci
- Centre for Kidney Disease Research-Venomics Research, School of Medicine, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Kong-Nan Zhao
- Centre for Kidney Disease Research-Venomics Research, School of Medicine, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia; Centre for Clinical Research, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD, 4029, Australia
| | - Nigel C Bennett
- Centre for Kidney Disease Research-Venomics Research, School of Medicine, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Goce Dimeski
- Chemical Pathology, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, QLD, 4102, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4078, Australia
| | - Michael Grant
- Q-Sera Pty Ltd, 278 Collins St, Melbourne, Vic, 3000, Australia
| | - Martin F Lavin
- Centre for Clinical Research, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD, 4029, Australia
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Purification and characterization of a thrombin-like enzyme isolated from Vipera lebetina venom: its interaction with platelet receptor. Blood Coagul Fibrinolysis 2019; 31:1-10. [PMID: 31764002 DOI: 10.1097/mbc.0000000000000856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
: Snake venoms contain various molecules that can be used as tools in the diagnosis and in the treatment of hemostatic disorders. This study reports the isolation and functional characterization of a new thrombin-like enzyme and its role in the modulation of platelet aggregation and coagulation. The molecule was purified by gel filtration, anion exchange chromatography and reverse-phase-HPLC on C8 column; its molecular weight was determined. Natural and synthetic substrates were used to evaluate its enzymatic activities. The fibrinogenolytic activity was tested electrophoretically and by reverse-phase-HPLC on C18 column. Otherwise, the effect on blood coagulation and deficient plasma factors were also evaluated. The mechanism by which a thrombin-like enzyme VLCV (thrombin-like enzyme)-induced platelet aggregation was explored in presence of ticlopidin, clopidogrel and aspirin. VLCV (45 kDa) isolated from Vipera lebetina as a thrombin-like enzyme seems to be able to modulate platelet function. This enzyme showed an amidolytic activity by hydrolyzing the chromogenic-specific substrate of thrombin and the α-chain of fibrinogen. It is also able to clot human plasma and the deficient human plasma in factor X, suggesting that it is involved in the intrinsic and common pathways. The aggregating effect of VLCV is more sensitive to ticlopidine than to the clopidogrel suggesting the involvement of ADP/P2Y12/PI3K pathway. VLCV seems to be able to promote human platelet aggregation suggesting an interaction between P2Y12 and PAR1. Due to its ability to replace the missing factor X and its proaggregating activity, VLCV could be used as molecular tool to better understand the hemostasis mechanism.
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Ferraz CR, Arrahman A, Xie C, Casewell NR, Lewis RJ, Kool J, Cardoso FC. Multifunctional Toxins in Snake Venoms and Therapeutic Implications: From Pain to Hemorrhage and Necrosis. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00218] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Allane D, Oussedik-Oumehdi H, Harrat Z, Seve M, Laraba-Djebari F. Isolation and characterization of an anti-leishmanial disintegrin fromCerastes cerastesvenom. J Biochem Mol Toxicol 2017; 32. [DOI: 10.1002/jbt.22018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 11/21/2017] [Accepted: 11/28/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Dihia Allane
- USTHB, Faculty of Biological Sciences; Laboratory of Cellular and Molecular Biology; Bab Ezzouar Algiers 16111 Algeria
| | - Habiba Oussedik-Oumehdi
- USTHB, Faculty of Biological Sciences; Laboratory of Cellular and Molecular Biology; Bab Ezzouar Algiers 16111 Algeria
| | - Zoubir Harrat
- Institut Pasteur d'Algérie; Service d'Eco-Epidémiologie Parasitaire; Dely Ibrahim Algiers 16 047 Algeria
| | - Michel Seve
- CHU Grenoble Alpes, Institut de Biologie et de Pathologie; Promethee Proteomic Platform; Grenoble France
| | - Fatima Laraba-Djebari
- USTHB, Faculty of Biological Sciences; Laboratory of Cellular and Molecular Biology; Bab Ezzouar Algiers 16111 Algeria
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7
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Abstract
Direct oral anticoagulants (DOACs) can be quantified using methods that can be performed in any clinical or research laboratory using manual or automated instrument platforms. Dabigatran etexilate, the oral direct thrombin inhibitor, can be quantified by drug-calibrated clot or chromogenic-based assays using either thrombin or ecarin as substrates. Oral direct anti-Xa inhibitors, such as rivaroxaban, apixaban, and edoxaban, can be quantified with drug-calibrated anti-Xa kits or reagents as typically used for measuring heparins (unfractionated, low molecular weight, or pentasaccharides).
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Affiliation(s)
- Robert C Gosselin
- Department of Pathology and Laboratory Medicine, Davis Health System, University of California, 4400 V Street, Sacramento, CA, 95817, USA.
| | - Jonathan Douxfils
- Department of Pharmacy, Namur Thrombosis and Hemostasis Center, Namur Research Institute for Life Sciences, University of Namur, Namur, Belgium
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Boukhalfa-Abib H, Laraba-Djebari F. CcMP-II, a new hemorrhagic metalloproteinase from Cerastes cerastes snake venom: purification, biochemical characterization and amino acid sequence analysis. Comp Biochem Physiol C Toxicol Pharmacol 2015; 167:65-73. [PMID: 25251459 DOI: 10.1016/j.cbpc.2014.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 09/03/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
Abstract
Snake venom metalloproteinases (SVMPs) are the most abundant components in snake venoms. They are important in the induction of systemic alterations and local tissue damage after envenomation. CcMP-II, which is a metalloproteinase purified from Cerastes cerastes snake venom, was obtained by a combination of gel filtration, ion-exchange and affinity chromatographies. It was homogeneous on SDS-PAGE, with a molecular mass estimated to 35kDa and presents a pI of 5.6. CcMP-II has an N-terminal sequence of EDRHINLVSVADHRMXTKY, with high levels of homology with those of the members of class P-II of SVMPs, which comprises metalloproteinase and disintegrin-like domains together. This proteinase displayed a fibrinogenolytic and hemorrhagic activities. The proteolytic and hemorrhagic activities of CcMP-II were inhibited by EDTA and 1,10-phenanthroline. However, these activities were not affected by aprotinine and PMSF, suggesting that CcMP-II is a zinc-dependent hemorrhagic metalloproteinase with an α-fibrinogenase activity. The hemorrhagic metalloproteinase CcMP-II was also able to hydrolyze extracellular matrix components, such as type IV collagen and laminin. These results indicate that CcMP-II is implicated in the local and systemic bleeding, contributing thus in the toxicity of C. cerastes venom.
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Affiliation(s)
- Hinda Boukhalfa-Abib
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32, El-Alia Bab Ezzouar, 16111 Algiers, Algeria
| | - Fatima Laraba-Djebari
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular and Molecular Biology, BP 32, El-Alia Bab Ezzouar, 16111 Algiers, Algeria.
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9
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Kumar KR, Vennila R, Kanchana S, Arumugam M, Balasubramaniam T. Fibrinogenolytic and anticoagulant activities in the tissue covering the stingers of marine stingrays Dasyatis sephen and Aetobatis narinari. J Thromb Thrombolysis 2011; 31:464-71. [PMID: 21165674 DOI: 10.1007/s11239-010-0537-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Stingray envenomation is one of the major problems in the marine and freshwater ecosystem. Accidents in human cause immediate, local and intense pain, erythema, edema, hemorrhage, tissue necrosis and secondary bacterial infection are also common. To determine the effect of two marine stingray species Dasyatis sephen and Aetobatis narinari venom extract on coagulation, fibrin(ogen)olytic, proteolytic activities. Plasma coagulation, Thrombin catalyzed fibrinocoagulation, Fibrin plate assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), substrate SDS-PAGE and thrombin like activity by using chromogenic substrate were used to determine the effect of venom on plasma coagulation, its fibrin(ogen)olytic and proteolytic activity. The results show the presence of fibrin(ogen)olytic, anticoagulant and gelatinolytic activity in both stingray venom extracts. D. sephen venom delays coagulation of citrated plasma more significantly than A. narinari upon using increasing concentration of the venom. The same results were obtained in the fibrinocoagulation assays. SDS-PAGE analysis of fibrinogen and fibrin after incubation with D. sephen and A. narinari venom show fibrin(ogen)olytic activity. Through SDS-PAGE analysis it is confirmed that the delaying in coagulation process by stingray venom is due to its fibrin(ogen)olytic activity and fibrinolytic activity also confirmed through fibrin plate assay. Zymogram analysis shows the presence of array of gelatinolytic and fibrinogenolytic enzymes above 43-276 kDa in the D. sephen and A. narinari venom respectively. Protease inhibitor studies show the serine and metallo proteases are responsible for these activities. From the results, fibrinogenolytic, proteolytic activity of the stingray venom is confirmed, but it has no thrombin like activity and these activities may aid in hemorrhages, tissue necrosis and secondary bacterial infections at the site of envenomation.
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Affiliation(s)
- Kalainesan Rajesh Kumar
- Center of Advanced Study in Marine Biology, Faculty of Marine Science, Annamalai University, Portonovo, P.O. Box 608502, Tamil Nadu, India.
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Kularatne SAM, Sivansuthan S, Medagedara SC, Maduwage K, de Silva A. Revisiting saw-scaled viper (Echis carinatus) bites in the Jaffna Peninsula of Sri Lanka: distribution, epidemiology and clinical manifestations. Trans R Soc Trop Med Hyg 2011; 105:591-7. [PMID: 21868049 DOI: 10.1016/j.trstmh.2011.07.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 07/15/2011] [Accepted: 07/15/2011] [Indexed: 10/17/2022] Open
Abstract
In Sri Lanka, the saw-scaled viper (Echis carinatus) is distributed in the arid, dry and sandy coastal plains and in a prospective study we describe its bites in the Jaffna peninsula. Of the 304 snake bite admissions to the Jaffna Hospital in 2009, 217 (71.4%) were bitten by either venomous species or envenomed by unidentified snakes. There were 99 (45.6%) reported saw-scaled viper bites, of which 26 were confirmed cases. The length of the offending snakes ranged from 228-310mm and bites mainly occurred in the nearby islands. The median age of the confirmed cases was 34 years (range 1.5-72 years); occupations included housewives (8, 31%), school children (4, 15%) and farmers (2, 8%). In 18 patients (69%), bites occurred in daylight and in 8 (31%) within or near the compounds. The fingers were bitten in 8 (31%) and toes/foot in 11 (42%) cases. There were 2 (8%) dry bites and 19 patients (73%) developed local swelling; one patient developed haemorrhagic blisters. In 24 patients (92%), blood incoagulability manifested between 40 and 1095min after the bite, and three patients (12%) developed spontaneous bleeding. One patient (4%) developed mild acute renal dysfunction. The median time for correction of coagulopathy was 802min (range 180-1669min) with Indian polyvalent antivenom. All recovered. The saw scaled viper is responsible for most venomous bites in the Jaffna peninsula.
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Affiliation(s)
- S A M Kularatne
- Department of Medicine, Faculty of Medicine, University of Peradeniya, Kandy, Sri Lanka.
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11
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Purification and characterization of a fibrinogenolytic and hemorrhagic metalloproteinase isolated from Vipera lebetina venom. Biochimie 2010; 92:797-805. [DOI: 10.1016/j.biochi.2010.02.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Accepted: 02/18/2010] [Indexed: 11/17/2022]
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12
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Oussedik-Oumehdi H, Laraba-Djebari F. IrradiatedCerastes cerastesVenom as a Novel Tool for Immunotherapy. Immunopharmacol Immunotoxicol 2008; 30:37-52. [DOI: 10.1080/08923970701812324] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Bennacef-Heffar N, Laraba-Djebari F. Evaluation of the effect of gamma rays on the venom of Vipera lebetina by biochemical study. Can J Physiol Pharmacol 2003; 81:1110-7. [PMID: 14719029 DOI: 10.1139/y03-112] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Snake bites represent a serious public health problem in many areas of the world. In Algeria, two widespread snakes are Vipera lebetina and Cerastes cerastes. Vipera lebetina venom causes local hemorrhage and necrosis, and it may lead to permanent limb loss. The principal causes of mortality after snakebites are acute renal failure and hemorrhage, which occur not only locally, at the site of the bite, but also systemically, contributing to the cardiovascular shock characteristic of severe envenomation. Gamma radiation has been shown to be effective for attenuating venom toxicity. Vipera lebetina venom was irradiated with two doses of gamma rays (1 and 2 kGy) from a 60Co source, and the venom's toxic, enzymatic, and structural properties were analyzed. Intraperitoneal injection of the irradiated venoms (100–500 µg/20 g mouse body mass) revealed a significant decrease of the toxicity. Irradiated venoms with 1 and 2 kGy doses were four and nine times less toxic, respectively, than the native venom. A biochemical characterization of in vitro enzymatic activities was performed. Vipera lebetina displayed in vitro caseinolytic, amidolytic, esterasic, coagulant, and phospholipase A2 activities. Caseinolytic, amidolytic, esterasic, and coagulative activities were reduced for the irradiated venoms; only phospholipase A2 activity was abolished in the irradiated venom with a dose of 2 kGy. The native and irradiated venoms were separated by gel filtration and electrophoresis. Chromatographic and electrophoretic profiles were drastically changed as compared with the native venom. Vipera lebetina venom detoxified by gamma rays was used for active immunization, and the presence of antibody in the immune sera was detected by ELISA. The immunogenic properties were preserved and the antisera obtained with the irradiated venoms could cross-react. Antisera were able to neutralize the toxic effect of V. lebetina native venom. These results indicate that irradiation of V. lebetina venom with a dose of 2 kGy can promote a significant detoxification, keeping the immunological properties intact.Key words: Vipera lebetina venom, gamma radiation, enzymes, detoxification, immune sera, immunoreactivity.
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Affiliation(s)
- Nouara Bennacef-Heffar
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Alger, Algérie
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14
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Abstract
Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization by activation of neuronal adenosine A(1) receptors, suppressing acetylcholine release from motor neurons and excitatory neurotransmitters from central sites. It also exacerbates venom-induced hypotension by activating A(2) receptors in the vasculature. Adenosine and inosine both activate mast cell A(3) receptors, liberating vasoactive substances and increasing vascular permeability. Guanosine probably contributes to hypotension, by augmenting vascular endothelial cGMP levels via an unknown mechanism. Novel functions are suggested for toxins that act upon blood coagulation factors, including nitric oxide production, using the prey's carboxypeptidases. Leucine aminopeptidase may link venom hemorrhagic metalloproteases and endogenous chymotrypsin-like proteases with venom L-amino acid oxidase (LAO), accelerating the latter. The primary function of LAO is probably to promote prey hypotension by activating soluble guanylate cyclase in the presence of superoxide dismutase. LAO's apoptotic activity, too slow to be relevant to prey capture, is undoubtedly secondary and probably serves principally a digestive function. It is concluded that the principal function of L-type Ca(2+) channel antagonists and muscarinic toxins, in Dendroaspis venoms, and acetylcholinesterase in other elapid venoms, is to promote hypotension. Venom dipeptidyl peptidase IV-like enzymes probably also contribute to hypotension by destroying vasoconstrictive peptides such as Peptide YY, neuropeptide Y and substance P. Purines apparently bind to other toxins which then serve as molecular chaperones to deposit the bound purines at specific subsets of purine receptors. The assignment of pharmacological activities such as transient neurotransmitter suppression, histamine release and antinociception, to a variety of proteinaceous toxins, is probably erroneous. Such effects are probably due instead to purines bound to these toxins, and/or to free venom purines.
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Affiliation(s)
- Steven D Aird
- Laboratório de Toxinas Naturais, Universidade Estadual do Ceará, Avenida Paranjana, 1700, Itaperí, 60740-000, Fortaleza, CE, Brazil.
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Beck KH, Kraus M, Magsaam J, Kretschmer V, Leonhard A, Seyberth HW. Prothrombin Marburg--a dysfunctional coagulation protein. Thromb Res 1997; 88:337-42. [PMID: 9526955 DOI: 10.1016/s0049-3848(97)00259-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- K H Beck
- Department of Transfusion Medicine and Blood Coagulation, University Hospital of Marburg, Germany
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16
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Nowak G, Bucha E. Prothrombin conversion intermediate effectively neutralizes toxic levels of hirudin. Thromb Res 1995; 80:317-25. [PMID: 8585044 DOI: 10.1016/0049-3848(95)00182-q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Meizothrombin, the stable intermediate product of ecarin-induced prothrombin conversion, was investigated for its ability to bind hirudin in blood. After in vitro pre-incubation of rat plasma with ecarin, the prolongation of the thrombin time caused by hirudin was reduced. The extent of hirudin neutralization was found to be dependent on the duration of incubation with ecarin. In vivo, after bilateral nephrectomy in Wistar rats and following administration of hirudin at a dose of 1 or 5 mg/kg, the blood level of hirudin remained constant after 2 h. After infusion of ecarin following hirudin administration, the hirudin blood level dropped sharply, reaching significantly reduced values, and bleeding stopped. Platelet count and fibrinogen level in plasma remained unchanged in the experiments using ecarin-induced prothrombin conversion intermediate generation. It is concluded that meizothrombin, a naturally occurring prothrombin conversion intermediate, provides an effective agent to neutralize toxic blood levels of hirudin.
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Affiliation(s)
- G Nowak
- Max-Planck-Gesellschaft e. V., Research Unit, Pharmacological Haemostaseology, Friedrich Schiller University, Jena, Germany
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17
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Laraba-Djebari F, Martin-Eauclaire MF, Marchot P. A fibrinogen-clotting serine proteinase from Cerastes cerastes (horned viper) venom with arginine-esterase and amidase activities. Purification, characterization and kinetic parameter determination. Toxicon 1992; 30:1399-410. [PMID: 1485336 DOI: 10.1016/0041-0101(92)90515-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An enzyme displaying proteolytic activity toward the natural substrate casein as well as clotting activity on fibrinogen was purified to homogeneity from Cerastes cerastes (horned viper) venom and characterized. The enzyme is constituted of two identical subunits of mol. wt 48,500 as determined by SDS-polyacrylamide gel electrophoresis, and has an isoelectric point of 3.75. N-terminal sequencing up to the 33rd residue evidenced a high homology with other snake venom proteinases. The proteinase is of serine-type as indicated by high sensitivity to DFP and shows both arginine-ester hydrolase and amidase activities on synthetic substrates. Both specific activities were 30-fold higher than the respective activities found in the crude venom. The Km value determined for arginine-containing substrate BAEE was 3.0 x 10(-4) M and the Km for chromogenic substrate CBS 34-47 0.65 x 10(-4) M. The Vm/Km ratio, however, was two-fold higher for BAEE than for CBS 34-47; the arginine-esterase activity of this enzyme is thus slightly higher than its amidase activity.
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Affiliation(s)
- F Laraba-Djebari
- Centre National de la Recherche Scientifique, Laboratoire de Biochimie, Faculté de Médecine, Marseille, France
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18
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Zotz RB, Mebs D, Hirche H, Paar D. Hemostatic changes due to the venom gland extract of the red-necked keelback snake (Rhabdophis subminiatus). Toxicon 1991; 29:1501-8. [PMID: 1801326 DOI: 10.1016/0041-0101(91)90006-d] [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: 12/28/2022]
Abstract
After a bite by the aglyphous red-necked keelback snake Rhabdophis subminiatus a complete defibrinogenation syndrome with severe hemorrhagic diathesis developed in a 25-year-old man. In vitro studies showed that the venom gland extract of the snake contains a very active prothrombin (Factor II) activator. The thrombin generated is inhibited neither by antithrombin III nor the antithrombin-III-heparin complex. The venom gland extract stimulated also the tissue plasminogen activator; however, it did not cause direct activation of plasminogen, protein C, Factor X or direct degradation of fibrinogen.
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Affiliation(s)
- R B Zotz
- Department of Medicine, University of Essen, F.R.G
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Vest DK, Mackessy SP, Kardong KV. The unique Duvernoy's secretion of the brown tree snake (Boiga irregularis). Toxicon 1991; 29:532-35. [PMID: 1862527 DOI: 10.1016/0041-0101(91)90029-q] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recently, bites by the colubrid Boiga irregularis (brown tree snake) in infants and young children on Guam have produced severe systemic reactions which bear some resemblance to classical manifestations of neurotoxic venom poisoning. This study demonstrates that the Duvernoy's secretion which elicits these reactions is a remarkably simple venom secretion with comparatively low toxicity and generally weak enzymatic activity. The intravenous LD50 for Swiss-Webster mice was approximately 80 mg/kg; significant neurotoxic manifestations were not observed in mouse trials. Deaths of lethally challenged mice occurred within minutes of injection, and appeared to result from cardiopulmonary crises. Duvernoy's secretion yields, protein content, enzyme activities, electrophoretic data and toxicity characteristics of the secretion are presented.
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Affiliation(s)
- D K Vest
- Department of Zoology, Washington State University, Pullman 99164-4236
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Kamiguti AS, Theakston RD, Tomy SC. An investigation of the coagulant activity of the venom of the saw-scaled viper (Echis carinatus) from Saudi Arabia. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1988; 82:503-9. [PMID: 3257079 DOI: 10.1080/00034983.1988.11812283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Unlike the venom of Echis carinatus from India, Pakistan, Nigeria, Kenya, Iran and Oman, Saudi Arabian E. carinatus venom is a poor activator of prothrombin. However, it possesses similar defibrinogenating activity to the other venoms. This is because the venom from Saudi Arabian snakes contains a calcium-dependent factor X activator. It is suggested that in future studies of the coagulant activity of venoms, the determination of plasma coagulant activity should be carried out in the presence of added calcium ions. This applies particularly to those venoms which do not act on plasma or fibrinogen, but which do cause in vivo defibrinogenation.
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Affiliation(s)
- A S Kamiguti
- Haematology Laboratory, Instituto Butantan, São Paulo, Brazil
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21
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Stocker K, Fischer H, Brogli M. Determination of factor X activator in the venom of the saw-scaled viper (Echis carinatus). Toxicon 1986; 24:313-5. [PMID: 3715901 DOI: 10.1016/0041-0101(86)90157-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Factor X activator in Echis carinatus venom was determined by incubating the zymogen 'factor X' with venom, interrupting the activation process by ethylenediaminetetraacetic acid and measuring the generated proteinase 'factor Xa' by means of a synthetic chromogenic substrate. A comparison of factor X- and prothrombin-activating potencies in E. carinatus venoms of five different geographic origins revealed no correlation between these two procoagulant activities.
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