PMID: 8948455Jun 15, 1995Paper

Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation

The Biochemical Journal
T KawasakiT Takenaka

Abstract

A new platelet antagonist, tokaracetin, was isolated from the venom of Trimeresurus tokarensis by ion-exchange chromatography, heparin-Sepharose chromatography and hydrophobic HPLC. The purified protein showed an apparent molecular mass on SDS/PAGE of 28.9 kDa under non-reducing conditions. On reduction, 16.1 and 15.4 kDa subunits were observed, suggesting that the molecule is a heterodimer. Tokaracetin inhibited the binding of 125I-labelled bovine von Willebrand factor (vWF) and 125I-labelled human vWF in the presence of botrocetin to fixed human platelets. It did not block ADP-, collagen- or thrombin receptor agonist peptide-induced platelet aggregation in human platelet-rich plasma (PRP), or induce platelet agglutination in PRP. On reduction, tokaracetin lost its inhibitory activity on the agglutination of fixed human platelets by bovine vWF. 125I-Tokaracetin specifically bound to washed human platelets with high affinity (Kd 3.9 +/- 1.4 nM) at 47,440 +/- 2780 binding sites per platelet. Binding of tokaracetin to fixed human platelets was reversible, and was inhibited by monoclonal antibody GUR83-35, which is directed against the N-terminal vWF-binding domain of human glycoprotein Ib (GPIb). Tokaracetin completely inhibited ...Continue Reading

Citations

Dec 12, 2017·BioMed Research International·Bruna Barbosa de SousaFábio de Oliveira
Mar 1, 2000·Toxicon : Official Journal of the International Society on Toxinology·R K Andrews, M C Berndt
Sep 15, 1999·Toxicon : Official Journal of the International Society on Toxinology·Y KomoriH Sugihara
Dec 5, 1998·Toxicon : Official Journal of the International Society on Toxinology·F S Markland
Oct 16, 2001·Toxicon : Official Journal of the International Society on Toxinology·H G ZhaY Zhang
Nov 1, 1996·Toxicon : Official Journal of the International Society on Toxinology·R M Kini
Dec 5, 1998·Toxicon : Official Journal of the International Society on Toxinology·H C CastroR B Zingali
Mar 22, 2005·Toxicon : Official Journal of the International Society on Toxinology·Gufeng XuLiwen Niu
May 7, 2005·Toxicon : Official Journal of the International Society on Toxinology·Qiumin LuKenneth J Clemetson
Sep 20, 2005·Toxicon : Official Journal of the International Society on Toxinology·Brent JenningsEnid Shephard

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antibodies: Agglutination

Antibody-mediated agglutination is the clumping of cells in the presence of antibody, which binds multiple cells together. This enhances the clearance of pathogens. Find the latest research on antibody-mediated agglutination here.

Blood Clotting Disorders

Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.