What question did this study set out to answer?

Investigate how the viper venom serine peptidases thrombocytin and PA-BJ interact with and activate human platelet thrombin receptors PAR1 and PAR4.

July 18, 2000FEBS Letters

Interaction of viper venom serine peptidases with thrombin receptors on human platelets

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Authors

BSBeatriz F. dos SantosUniversidade Federal da Grande Dourados SSSolange M.T. SerranoInstituto Butantan AKAthan KuliopulosTufts University

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Implication

Laboratory study reveals that viper venom peptidases cleave PAR1 and activate PAR4 on human platelets, highlighting dual receptor pathways in venom-induced aggregation.

Key Points

Investigate how the viper venom serine peptidases thrombocytin and PA-BJ interact with and activate human platelet thrombin receptors PAR1 and PAR4.
Assayed platelet aggregation, granule secretion, and calcium mobilization induced by thrombocytin (Bothrops atrox) and PA-BJ (Bothrops jararaca) using PAR1 antibodies, heparin, hirudin, and thrombomodulin.
Mapped enzymatic cleavage sites on the soluble N-terminal domain of PAR1 and measured calcium mobilization in PAR4-transfected fibroblasts.
Thrombocytin and PA-BJ exhibited approximately 15-fold lower platelet aggregation activity than thrombin, an effect blocked by anti-PAR1 antibodies and heparin but not by hirudin or thrombomodulin.
Both viper peptidases cleaved PAR1 at Arg41-Ser42 and rapidly cleaved Arg46-Asn47, leading to tethered ligand inactivation and degradation of fragment 42-103.
Both enzymes induced calcium mobilization in PAR4-transfected fibroblasts and desensitized the cells to subsequent thrombin activation.

Cite This Study

Santos et al. (2000) studied this question.

synapsesocial.com/papers/6a86cdb65ee22a1e35cb9448 https://doi.org/10.1016/s0014-5793(00)01803-2

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Implication

Laboratory study reveals that viper venom peptidases cleave PAR1 and activate PAR4 on human platelets, highlighting dual receptor pathways in venom-induced aggregation.

Interaction of viper venom serine peptidases with thrombin receptors on human platelets

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Implication

Key Points

Cite This Study

Interaction of viper venom serine peptidases with thrombin receptors on human platelets

Discussion

Member takes

Implication

Key Points

Cite This Study

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