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

T. Kawasaki, Y. Taniuchi, N. Hisanichi, Y. Fujimura, M. Suzuki, K. Titani, Y. Sakai, S. Kaku, N. Satoh, T. Takenaka, M. Handa, Y. Sawai

Research output: Contribution to journalArticle

60 Citations (Scopus)

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 (K(d) 3.9 ± 1.4 nM) at 47440 ± 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 vWF-dependent shear-induced platelet aggregation in PRP at 3 μg/ml. The N-terminal amino acid sequences of tokaracetin subunits showed a high degree of identity with those of alboaggregin-B. These results suggest that this new platelet antagonist may be a useful tool in the development of specific inhibitors of the vWF-GPIb interaction.

Original languageEnglish
Pages (from-to)947-953
Number of pages7
JournalBiochemical Journal
Volume308
Issue number3
Publication statusPublished - 1995
Externally publishedYes

Fingerprint

Platelet Glycoprotein GPIb-IX Complex
Platelet Membrane Glycoproteins
Platelet Aggregation Inhibitors
von Willebrand Factor
Platelets
Platelet Aggregation
Agglomeration
Blood Platelets
Platelet-Rich Plasma
Agglutination
Collagen Receptors
Thrombin Receptors
Purinergic P2 Receptors
Chromatography
Plasmas
Agarose Chromatography
Ion Exchange Chromatography
tokaracetin
Polyacrylamide Gel Electrophoresis
Amino Acid Sequence

ASJC Scopus subject areas

  • Biochemistry

Cite this

Kawasaki, T., Taniuchi, Y., Hisanichi, N., Fujimura, Y., Suzuki, M., Titani, K., ... Sawai, Y. (1995). Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation. Biochemical Journal, 308(3), 947-953.

Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation. / Kawasaki, T.; Taniuchi, Y.; Hisanichi, N.; Fujimura, Y.; Suzuki, M.; Titani, K.; Sakai, Y.; Kaku, S.; Satoh, N.; Takenaka, T.; Handa, M.; Sawai, Y.

In: Biochemical Journal, Vol. 308, No. 3, 1995, p. 947-953.

Research output: Contribution to journalArticle

Kawasaki, T, Taniuchi, Y, Hisanichi, N, Fujimura, Y, Suzuki, M, Titani, K, Sakai, Y, Kaku, S, Satoh, N, Takenaka, T, Handa, M & Sawai, Y 1995, 'Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation', Biochemical Journal, vol. 308, no. 3, pp. 947-953.
Kawasaki, T. ; Taniuchi, Y. ; Hisanichi, N. ; Fujimura, Y. ; Suzuki, M. ; Titani, K. ; Sakai, Y. ; Kaku, S. ; Satoh, N. ; Takenaka, T. ; Handa, M. ; Sawai, Y. / Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation. In: Biochemical Journal. 1995 ; Vol. 308, No. 3. pp. 947-953.
@article{e5c66de6868547bebe08dd4d088cae54,
title = "Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation",
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 (K(d) 3.9 ± 1.4 nM) at 47440 ± 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 vWF-dependent shear-induced platelet aggregation in PRP at 3 μg/ml. The N-terminal amino acid sequences of tokaracetin subunits showed a high degree of identity with those of alboaggregin-B. These results suggest that this new platelet antagonist may be a useful tool in the development of specific inhibitors of the vWF-GPIb interaction.",
author = "T. Kawasaki and Y. Taniuchi and N. Hisanichi and Y. Fujimura and M. Suzuki and K. Titani and Y. Sakai and S. Kaku and N. Satoh and T. Takenaka and M. Handa and Y. Sawai",
year = "1995",
language = "English",
volume = "308",
pages = "947--953",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "3",

}

TY - JOUR

T1 - Tokaracetin, a new platelet antagonist that binds to platelet glycoprotein Ib and inhibits von Willebrand factor-dependent shear-induced platelet aggregation

AU - Kawasaki, T.

AU - Taniuchi, Y.

AU - Hisanichi, N.

AU - Fujimura, Y.

AU - Suzuki, M.

AU - Titani, K.

AU - Sakai, Y.

AU - Kaku, S.

AU - Satoh, N.

AU - Takenaka, T.

AU - Handa, M.

AU - Sawai, Y.

PY - 1995

Y1 - 1995

N2 - 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 (K(d) 3.9 ± 1.4 nM) at 47440 ± 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 vWF-dependent shear-induced platelet aggregation in PRP at 3 μg/ml. The N-terminal amino acid sequences of tokaracetin subunits showed a high degree of identity with those of alboaggregin-B. These results suggest that this new platelet antagonist may be a useful tool in the development of specific inhibitors of the vWF-GPIb interaction.

AB - 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 (K(d) 3.9 ± 1.4 nM) at 47440 ± 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 vWF-dependent shear-induced platelet aggregation in PRP at 3 μg/ml. The N-terminal amino acid sequences of tokaracetin subunits showed a high degree of identity with those of alboaggregin-B. These results suggest that this new platelet antagonist may be a useful tool in the development of specific inhibitors of the vWF-GPIb interaction.

UR - http://www.scopus.com/inward/record.url?scp=0028998074&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028998074&partnerID=8YFLogxK

M3 - Article

C2 - 8948455

AN - SCOPUS:0028998074

VL - 308

SP - 947

EP - 953

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 3

ER -