Abstract
Two novel proteins, jararhagin and jaracetin, were purified from Bothrops jararaca viper venom. Jararhagin is a 55-kDa member of the metalloprotease-disintegrin family. Jaracetin is a 60-kDa dimer representing a differently processed form of jararhagin. Like botrocetin, a previously described viper venom protein, jararhagin and jaracetin modulated binding of von Willebrand Factor to the glycoprotein Ib-IX complex on platelets through a specific interaction with the von Willebrand Factor A1 domain. Both jararhagin and jaracetin, but not botrocetin, also blocked alpha 2 beta 1-dependent platelet adhesion to collagen, a receptor interaction mediated through a homologous A domain on the integrin alpha 2 subunit.
MeSH terms
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Animals
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Antibodies, Monoclonal / pharmacology
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Antigens, CD / drug effects
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Blood Platelets / metabolism*
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Bothrops
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Bothrops jararaca Venom
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Chromatography, Ion Exchange
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Collagen
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Crotalid Venoms / isolation & purification
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Crotalid Venoms / pharmacology*
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Electrophoresis, Polyacrylamide Gel
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Humans
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Integrin beta1
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Integrins / antagonists & inhibitors*
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Integrins / drug effects
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Kinetics
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Metalloendopeptidases / isolation & purification
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Metalloendopeptidases / pharmacology*
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Molecular Weight
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Platelet Adhesiveness / drug effects*
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Platelet Aggregation Inhibitors / pharmacology*
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Receptors, Collagen
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Receptors, Thrombin / antagonists & inhibitors*
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von Willebrand Factor / metabolism
Substances
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Antibodies, Monoclonal
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Antigens, CD
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Crotalid Venoms
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Integrin beta1
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Integrins
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Platelet Aggregation Inhibitors
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Receptors, Collagen
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Receptors, Thrombin
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von Willebrand Factor
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Collagen
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Metalloendopeptidases