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Development of a Carotid Artery Thrombolysis (iCAT) Stroke Model in Mice. Blood Adv 2022; 6:5449-5462. [PMID: 35767737 PMCID: PMC9631707 DOI: 10.1182/bloodadvances.2021006008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 06/21/2022] [Indexed: 11/20/2022] Open
Abstract
Development of a mouse carotid artery thrombolysis model of stroke. iCAT enables assessment of adjunctive antithrombotic therapies on arterial recanalization, cerebral perfusion, and stroke outcomes.
Recanalization with restored cerebral perfusion is the primary goal of thrombolytic therapy in acute ischemic stroke. The identification of adjunctive therapies that can be safely used to enhance thrombolysis in stroke remains an elusive goal. We report here the development of a mouse in situ carotid artery thrombolysis (iCAT) stroke model involving graded cerebral ischemia to induce unihemispheric infarction after thrombotic occlusion of the common carotid artery (CCA). Electrolytic-induced thrombotic occlusion of the left CCA enabled real-time assessment of recanalization and rethrombosis events after thrombolysis with recombinant tissue-type plasminogen activator (rtPA). Concurrent transient stenosis of the right CCA induced unihemispheric hypoperfusion and infarction in the left middle cerebral artery territory. Real-time assessment of thrombolysis revealed recanalization rates <30% in rtPA-treated animals with high rates of rethrombosis. Addition of the direct thrombin inhibitor argatroban increased recanalization rates to 50% and reduced rethrombosis. Paradoxically, this was associated with increased cerebral ischemia and stroke-related mortality (25%-42%). Serial analysis of carotid and cerebral blood flow showed that coadministration of argatroban with rtPA resulted in a marked increase in carotid artery embolization, leading to distal obstruction of the middle cerebral artery. Real-time imaging of carotid thrombi revealed that adjunctive anticoagulation destabilized platelet-rich thrombi at the vessel wall, leading to dislodgement of large platelet emboli. These studies confirm the benefits of anticoagulants in enhancing thrombolysis and large artery recanalization; however, at high levels of anticoagulation (∼3-fold prolongation of activated partial thromboplastin time), this effect is offset by increased incidence of carotid artery embolization and distal middle cerebral artery occlusion. The iCAT stroke model should provide important new insight into the effects of adjunctive antithrombotic agents on real-time thrombus dynamics during thrombolysis and their correlation with stroke outcomes.
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Sanchez EF, Flores-Ortiz RJ, Alvarenga VG, Eble JA. Direct Fibrinolytic Snake Venom Metalloproteinases Affecting Hemostasis: Structural, Biochemical Features and Therapeutic Potential. Toxins (Basel) 2017; 9:toxins9120392. [PMID: 29206190 PMCID: PMC5744112 DOI: 10.3390/toxins9120392] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 02/06/2023] Open
Abstract
Snake venom metalloproteinases (SVMPs) are predominant in viperid venoms, which provoke hemorrhage and affect hemostasis and thrombosis. P-I class enzymes consist only of a single metalloproteinase domain. Despite sharing high sequence homology, only some of them induce hemorrhage. They have direct fibrin(ogen)olytic activity. Their main biological substrate is fibrin(ogen), whose Aα-chain is degraded rapidly and independently of activation of plasminogen. It is important to understand their biochemical and physiological mechanisms, as well as their applications, to study the etiology of some human diseases and to identify sites of potential intervention. As compared to all current antiplatelet therapies to treat cardiovascular events, the SVMPs have outstanding biochemical attributes: (a) they are insensitive to plasma serine proteinase inhibitors; (b) they have the potential to avoid bleeding risk; (c) mechanistically, they are inactivated/cleared by α2-macroglobulin that limits their range of action in circulation; and (d) few of them also impair platelet aggregation that represent an important target for therapeutic intervention. This review will briefly highlight the structure–function relationships of these few direct-acting fibrinolytic agents, including, barnettlysin-I, isolated from Bothrops barnetti venom, that could be considered as potential agent to treat major thrombotic disorders. Some of their pharmacological advantages are compared with plasmin.
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Affiliation(s)
- Eladio F Sanchez
- Research and Development Center, Ezequiel Dias Foundation, Belo Horizonte 30510-010, MG, Brazil.
| | - Renzo J Flores-Ortiz
- Graduate Program in Nursing, Federal University of Minas Gerais, Belo Horizonte 30130-100, MG, Brazil.
| | - Valeria G Alvarenga
- Research and Development Center, Ezequiel Dias Foundation, Belo Horizonte 30510-010, MG, Brazil.
| | - Johannes A Eble
- Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, 15, 48149 Muenster, Germany.
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Adivitiya, Khasa YP. The evolution of recombinant thrombolytics: Current status and future directions. Bioengineered 2016; 8:331-358. [PMID: 27696935 DOI: 10.1080/21655979.2016.1229718] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cardiovascular disorders are on the rise worldwide due to alcohol abuse, obesity, hypertension, raised blood lipids, diabetes and age-related risks. The use of classical antiplatelet and anticoagulant therapies combined with surgical intervention helped to clear blood clots during the inceptive years. However, the discovery of streptokinase and urokinase ushered the way of using these enzymes as thrombolytic agents to degrade the fibrin network with an issue of systemic hemorrhage. The development of second generation plasminogen activators like anistreplase and tissue plasminogen activator partially controlled this problem. The third generation molecules, majorly t-PA variants, showed desirable properties of improved stability, safety and efficacy with enhanced fibrin specificity. Plasmin variants are produced as direct fibrinolytic agents as a futuristic approach with targeted delivery of these drugs using liposome technlogy. The novel molecules from microbial, plant and animal origin present the future of direct thrombolytics due to their safety and ease of administration.
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Affiliation(s)
- Adivitiya
- a Department of Microbiology , University of Delhi South Campus , New Delhi , India
| | - Yogender Pal Khasa
- a Department of Microbiology , University of Delhi South Campus , New Delhi , India
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Sanchez EF, Richardson M, Gremski LH, Veiga SS, Yarleque A, Niland S, Lima AM, Estevao-Costa MI, Eble JA. A novel fibrinolytic metalloproteinase, barnettlysin-I from Bothrops barnetti (Barnett´s pitviper) snake venom with anti-platelet properties. Biochim Biophys Acta Gen Subj 2015; 1860:542-56. [PMID: 26723171 DOI: 10.1016/j.bbagen.2015.12.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Viperid snake venoms contain active components that interfere with hemostasis. We report a new P-I class snake venom metalloproteinase (SVMP), barnettlysin-I (Bar-I), isolated from the venom of Bothrops barnetti and evaluated its fibrinolytic and antithrombotic potential. METHODS Bar-I was purified using a combination of molecular exclusion and cation-exchange chromatographies. We describe some biochemical features of Bar-I associated with its effects on hemostasis and platelet function. RESULTS Bar-I is a 23.386 kDa single-chain polypeptide with pI of 6.7. Its sequence (202 residues) shows high homology to other members of the SVMPs. The enzymatic activity on dimethylcasein (DMC) is inhibited by metalloproteinase inhibitors e.g. EDTA, and by α2-macroglobulin. Bar-I degrades fibrin and fibrinogen dose- and time-dependently by cleaving their α-chains. Furthermore, it hydrolyses plasma fibronectin but not laminin nor collagen type I. In vitro Bar-I dissolves fibrin clots made either from purified fibrinogen or from whole blood. In contrast to many other P-I SVMPs, Bar-I is devoid of hemorrhagic activity. Also, Bar-I dose- and time-dependently inhibits aggregation of washed human platelets induced by vWF plus ristocetin and collagen (IC50=1.3 and 3.2 μM, respectively), presumably Bar-I cleaves both vWF and GPIb. Thus, it effectively inhibits vWF-induced platelet aggregation. Moreover, this proteinase cleaves the collagen-binding α2-A domain (160 kDa) of α2β1-integrin. This explains why it additionally inhibits collagen-induced platelet activation. CONCLUSION A non-hemorrhagic but fibrinolytic metalloproteinase dissolves fibrin clots in vitro and impairs platelet function. GENERAL SIGNIFICANCE This study provides new opportunities for drug development of a fibrinolytic agent with antithrombotic effect.
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Affiliation(s)
- Eladio Flores Sanchez
- Research and Development Center, Ezequiel Dias Foundation, 30510-010, Belo Horizonte, MG, Brazil; Faculty of Biological Sciences, Nacional University of San Marcos, Lima-Peru.
| | - Michael Richardson
- Research and Development Center, Ezequiel Dias Foundation, 30510-010, Belo Horizonte, MG, Brazil
| | | | | | - Armando Yarleque
- Faculty of Biological Sciences, Nacional University of San Marcos, Lima-Peru
| | - Stephan Niland
- Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Germany
| | - Augusto Martins Lima
- Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Germany
| | - Maria Inácia Estevao-Costa
- Research and Development Center, Ezequiel Dias Foundation, 30510-010, Belo Horizonte, MG, Brazil; Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Germany
| | - Johannes Andreas Eble
- Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Germany
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Bilheiro RP, Braga AD, Filho ML, Carvalho-Tavares J, Agero U, Carvalho MDG, Sanchez EF, Salas CE, Lopes MTP. The thrombolytic action of a proteolytic fraction (P1G10) from Carica candamarcensis. Thromb Res 2013; 131:e175-82. [PMID: 23473638 DOI: 10.1016/j.thromres.2013.01.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 01/18/2013] [Accepted: 01/22/2013] [Indexed: 01/03/2023]
Abstract
A group of cysteine-proteolytic enzymes from C. candamarcensis latex, designated as P1G10 displays pharmacological properties in animal models following various types of lesions. This enzyme fraction expresses in vitro fibrinolytic effect without need for plasminogen activation. Based on this evidence, we assessed by intravital microscopy the effect of P1G10 on recanalization of microvessels after thrombus induction in the ear of hairless mice. Video playback of intravital microscopic images allowed measurement of blood flow velocity (mm/s) during the experimental procedure. Groups treated with 5 or 7.5mg/Kg P1G10 showed thrombolysis between 7-15min, without vessel obstruction. Ex vivo experiments demonstrated that platelet activation by ADP is impaired in a dose dependent manner following treatment with P1G10. The P1G10 action on plasma coagulation also showed that prothrombin time (PT), thrombin time (TT) and activated partial thromboplastin time (aPTT, μg/uL) are increased in a dose dependent manner. In addition, P1G10 displayed fibrinogenolytic and fibrinolytic activities, both in a dose dependent manner. Each of these effects was suppressed by inhibition of the proteolytic activity of the fraction. The antithrombotic action of P1G10 can be explained by proteolytic cleavage of fibrinogen and fibrin, both key factors during formation of a stable thrombus. These results combined with prior evidence suggest that P1G10 has potential as thrombolytic agent.
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Affiliation(s)
- Rogério P Bilheiro
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Markland FS, Swenson S. Fibrolase: trials and tribulations. Toxins (Basel) 2010; 2:793-808. [PMID: 22069611 PMCID: PMC3153196 DOI: 10.3390/toxins2040793] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 03/31/2010] [Accepted: 04/19/2010] [Indexed: 11/23/2022] Open
Abstract
Fibrolase is the fibrinolytic enzyme isolated from Agkistrodon contortrix contortrix (southern copperhead snake) venom. The enzyme was purified by a three-step HPLC procedure and was shown to be homogeneous by standard criteria including reverse phase HPLC, molecular sieve chromatography and SDS-PAGE. The purified enzyme is a zinc metalloproteinase containing one mole of zinc. It is composed of 203 amino acids with a blocked amino-terminus due to cyclization of the terminal Gln residue. Fibrolase shares a significant degree of homology with enzymes of the reprolysin sub-family of metalloproteinases including an active site homology of close to 100%; it is rapidly inhibited by chelating agents such as EDTA, and by alpha2-macroglobulin (α2Μ). The enzyme is a direct-acting thrombolytic agent and does not rely on plasminogen for clot dissolution. Fibrolase rapidly cleaves the A(α)-chain of fibrinogen and the B(β)-chain at a slower rate; it has no activity on the γ-chain. The enzyme exhibits the same specificity with fibrin, cleaving the α-chain more rapidly than the β-chain. Fibrolase was shown to have very effective thrombolytic activity in a reoccluding carotid arterial thrombosis model in the canine. A recombinant version of the enzyme was made in yeast by Amgen, Inc. (Thousand Oaks, CA, USA) and called alfimeprase. Alfimeprase is identical to fibrolase except for a two amino acid truncation at the amino-terminus and the insertion of a new amino-terminal amino acid in the truncated protein; these changes lead to a more stable enzyme for prolonged storage. Alfimeprase was taken into clinical trials by Nuvelo, Inc. (San Carlos, CA), which licensed the enzyme from Amgen. Alfimeprase was successful in Phase I and II clinical trials for peripheral arterial occlusion (PAO) and central venous access device (CVAD) occlusion. However, in Phase III trials alfimeprase did not meet the expected end points in either PAO or CVAD occlusion and in a Phaase II stroke trial, and Nuvelo dropped further development in 2008.
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Affiliation(s)
- Francis S. Markland
- Department of Biochemistry and Molecular Biology, Cancer Research Laboratory, Keck School of Medicine, University of Southern California, 1303 N. Mission Rd., Los Angeles, CA 90033, USA
- USC/Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
- Author to whom correspondence should be addressed; ; Tel.: +1-(323) 224-7981; Fax: +1-(323) 224-7679
| | - Steve Swenson
- Department of Biochemistry and Molecular Biology, Cancer Research Laboratory, Keck School of Medicine, University of Southern California, 1303 N. Mission Rd., Los Angeles, CA 90033, USA
- USC/Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
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Marder VJ, Novokhatny V. Direct fibrinolytic agents: biochemical attributes, preclinical foundation and clinical potential. J Thromb Haemost 2010; 8:433-44. [PMID: 19943877 DOI: 10.1111/j.1538-7836.2009.03701.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Direct fibrinolytics are proteolytic enzymes that degrade fibrin without requiring an intermediate step of plasminogen activation. This review summarizes the current information available for five such agents, namely, plasmin (the prototypical form), three derivatives of plasmin (mini-plasmin, micro-plasmin, and delta-plasmin), and alfimeprase, a recombinant variant of a snake venom alpha-fibrinogenase, fibrolase. Biochemical attributes of molecular size, fibrin binding and inhibitor neutralization are compared. Preclinical investigations that assess the potential for thrombolytic efficacy in vitro and in animal models of vascular occlusion and for hemostatic safety in animal models of bleeding are detailed. Clinical potential has been assessed in patients with peripheral arterial and graft occlusion, acute ischemic stroke, and access catheter and hemodialysis shunt occlusions. The direct fibrinolytic agents have impressive biochemical and preclinical foundations for ultimate clinical application. However, clinical trial results for micro-plasmin and alfimeprase have not measured up to their anticipated benefit. Plasmin has thus far shown encouraging hemostatic safety, but efficacy data await completion of clinical trials. Whether direct fibrinolytics will provide clinical superiority in major thrombotic disorders over currently utilized indirect fibrinolytics such as tissue plasminogen activator remains to be determined.
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Affiliation(s)
- V J Marder
- Hematology/Medical Oncology Division, Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Lauver DA, Driscoll EM, Lucchesi BR. Disodium disuccinate astaxanthin prevents carotid artery rethrombosis and ex vivo platelet activation. Pharmacology 2008; 82:67-73. [PMID: 18477858 DOI: 10.1159/000132085] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Accepted: 02/11/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS The disodium disuccinate derivative of astaxanthin (DDA) is a carotenoid antioxidant under development for the treatment of ischemic cardiovascular events. Recent evidence suggests that reactive oxygen species (ROS) play an important role in platelet activation. This study seeks to investigate the effects of a reactive oxygen species quencher, DDA, in a canine model of carotid artery thrombosis. METHODS After formation of an occlusive carotid thrombus, dogs were administered recombinant tissue plasminogen activator intra-arterially to achieve thrombolysis in the presence of either 0.9% NaCl solution or DDA (10-50 mg/kg i.v. infusion). Ex vivo platelet aggregation and tongue bleeding times were measured before and after drug administration. Residual thrombus mass was analyzed at the end of each experiment. RESULTS The data indicated a dose- dependent reduction in the incidence of carotid artery rethrombosis. In addition, platelet aggregation and thrombus weights were dose-dependently inhibited by DDA. No change was recorded in tongue bleeding time among the treatment groups. CONCLUSIONS The data demonstrate that at the doses used in this study, DDA significantly reduced the incidence of secondary thrombosis while maintaining normal hemostasis. The results suggest that upon further study, DDA may one day find utility in revascularization procedures.
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Affiliation(s)
- D Adam Lauver
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Mich 48109, USA
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Moise MA, Kashyap VS. Alfimeprase for the treatment of acute peripheral arterial occlusion. Expert Opin Biol Ther 2008; 8:683-9. [DOI: 10.1517/14712598.8.5.683] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Agero U, Arantes RME, Lacerda-Queiroz N, Mesquita ON, Magalhães A, Sanchez EF, Carvalho-Tavares J. Effect of mutalysin II on vascular recanalization after thrombosis induction in the ear of the hairless mice model. Toxicon 2007; 50:698-706. [PMID: 17681580 DOI: 10.1016/j.toxicon.2007.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 06/01/2007] [Accepted: 06/04/2007] [Indexed: 10/23/2022]
Abstract
Mutalysin II (mut-II) is an alpha-fibrinogenase isolated from Lachesis muta muta (bushmaster) snake venom. The enzyme lyses fibrin clots in vitro, and this activity does not depend on plasminogen activation. The aim of this study was to assess by intravital microscopy the effect of Mutalysin II on the recanalization of microvessels after thrombus induction in the ears of hairless mice. Photochemical thrombus formation was induced after i.v. injection of 5% fluorescein isothiocyanate labelled dextran (FITC-dextran) followed by mercury light exposure of individual microvessels of the ear of five anesthetized animals. Video playback analysis of intravital microscopy images of the ear microcirculation permitted us to measure blood flow velocity (microm/s) under control conditions (before thrombus formation) in the ear microvessels. Thirty minutes after thrombus formation (blood flow velocity stopped completely), each animal (n=5) was infused with Mutalysin II (2.0 mg/kg, i.v.). All animals treated with Mutalysin II showed evident thrombolysis after approximately 12 min, followed by recanalization. A separate group of mice (n=5) which received urokinase type-plasminogen activator (u-PA, 250 U/mouse, i.v.) showed blood flow restoration within the same interval (12 min). These in vivo data suggest that Mutalysin II has the potential to be an effective thrombolytic agent.
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Affiliation(s)
- Ubirajara Agero
- Departamento de Física, Instituto de Ciência Exatas Universidade Federal de Minas Gerais, Brazil
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Leonardi A, Fox JW, Trampus-Bakija A, Krizaj I. Ammodytase, a metalloprotease from Vipera ammodytes ammodytes venom, possesses strong fibrinolytic activity. Toxicon 2007; 49:833-42. [PMID: 17250863 DOI: 10.1016/j.toxicon.2006.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 12/05/2006] [Accepted: 12/11/2006] [Indexed: 11/15/2022]
Abstract
Ammodytase, a high molecular mass metalloproteinase with fibrinogenolytic and fibrinolytic activities, was purified from long-nosed viper (Vipera ammodytes ammodytes) venom by gel filtration, affinity and ion-exchange chromatographies. The enzyme is a single-chain glycoprotein with apparent molecular mass of 70 kDa and isoelectric point of 6.6. Ammodytase shows very weak hemorrhagic activity, and only at doses higher than 20 microg. Consistent with this, it partially degrades some components of the extracellular matrix in vitro. It cleaves the Aalpha-chain of fibrinogen preferentially at peptide bonds Glu(441)-Leu(442) and Glu(539)-Phe(540). Its preference for bulky and hydrophobic amino acids at the P1' position in substrates is demonstrated by its hydrolysis of only the Gln(4)-His(5) and Tyr(16)-Leu(17) bonds in the B-chain of insulin. Ammodytase is able to dissolve fibrin clots. It neither activates nor degrades plasminogen and prothrombin, and has no effect on collagen- or ADP-induced platelet aggregation in vitro. LC/MS and MS/MS analyses of its tryptic fragments demonstrated that ammodytase is a P-III class snake venom metalloproteinase composed of metalloproteinase, disintegrin-like and cysteine-rich domains. Its similarity to hemorrhagins from V. a. ammodytes venom, accompanied by very low toxicity, makes ammodytase a promising candidate as an antigen to prepare antisera against these most dangerous components of the viper's venom. Moreover, its ability to degrade fibrin clots suggests its clinical use as an antithrombotic agent.
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Affiliation(s)
- Adrijana Leonardi
- Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Ljubljana, Slovenia
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Deitcher SR, Funk WD, Buchanan J, Liu S, Levy MD, Toombs CF. Alfimeprase: a novel recombinant direct-acting fibrinolytic. Expert Opin Biol Ther 2006; 6:1361-9. [PMID: 17223743 DOI: 10.1517/14712598.6.12.1361] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Alfimeprase is a recombinant, direct-acting fibrinolytic zinc metalloprotease. Alfimeprase has direct proteolytic activity primarily against the fibrin(ogen) Aalpha chain. Alfimeprase is covalently bound and neutralised by serum alpha(2)-macroglobulin, a prevalent mammalian protease inhibitor. Preclinical pharmacology studies have shown that fibrinolysis with alfimeprase is up to sixfold more rapid than with select plasminogen activators, such as tissue-type plasminogen activator and urokinase. Alfimeprase directly delivered to a site of thrombosis has the potential to be a fast and effective fibrinolytic, which does not generate the systemic lytic state seen with plasminogen activators that is associated with major bleeding, including intracerebral haemorrhage. Phase I and II studies in individuals with arterial or venous thrombotic events indicate that alfimeprase is active and generally well tolerated.
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Affiliation(s)
- Steven R Deitcher
- Nuvelo, Inc., 201 Industrial Road, Suite 310, San Carlos, CA 94070, USA.
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