Flavocetin-A and -B, two high molecular mass glycoprotein Ib binding proteins with high affinity purified from Trimeresurus flavoviridis venom, inhibit platelet aggregation at high shear stress

Yuta Taniuchi, Tomihisa Kawasaki, Yoshihiro Fujimura, Masami Suzuki, Koiti Titani, Yumiko Sakai, Seiji Kaku, Nami Hisamichi, Noboru Satoh, Toichi Takenaka, Makoto Handa, Yoshio Sawai

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Abstract

Two high molecular mass proteins, flavocetin-A and flavocetin-B, were purified from Trimeresurus flavoviridis venom. On polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the apparent molecular mass of flavocetin-A and -B were 149 and 139 kDa, respectively, under nonreducing conditions. On reduction, flavocetin-A showed two distinct subunits (17 and 14 kDa), and flavocetin-B three distinct subunits (17, 15 and 14 kDa). At 1 μg/ml, flavocetin-A and -B (flavocetins) inhibited the von Willebrand factor (vWF)-dependent aggregation of fixed human platelets. However, flavocetins (10 μg/ml) had no effect on ADP- and collagen-induced platelet aggregation in PRP. Flavocetins (3 μg/ml) also inhibited shear-induced platelet aggregation at high shear stress. Furthermore, flavocetin-A completely inhibited the aggregation of and ATP release from washed platelets stimulated with a low concentration of thrombin. Flavocetin-A specifically bound to platelet with high affinity (Kd = 0.35 ± 0.13 nM) at 21 500 ± 1760 binding sites per platelet. The N-terminal amino acid sequences of the subunits of flavocetin-A show a high degree of homology with those of echicetin, botrocetin, alboaggregin-B and factor IX/factor X-binding protein. These results suggest that flavocetins may be a useful tool for further investigation of the GPIb-vWF interaction.

Original languageEnglish
Pages (from-to)331-338
Number of pages8
JournalBBA - General Subjects
Volume1244
Issue number2-3
DOIs
Publication statusPublished - 1995 Jun 9

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Keywords

  • (Snake venom)
  • Flavocetin-A and -B
  • Glycoprotein Ib
  • Platelet aggregation
  • Shear stress
  • Von Willebrand factor

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

Cite this

Taniuchi, Y., Kawasaki, T., Fujimura, Y., Suzuki, M., Titani, K., Sakai, Y., Kaku, S., Hisamichi, N., Satoh, N., Takenaka, T., Handa, M., & Sawai, Y. (1995). Flavocetin-A and -B, two high molecular mass glycoprotein Ib binding proteins with high affinity purified from Trimeresurus flavoviridis venom, inhibit platelet aggregation at high shear stress. BBA - General Subjects, 1244(2-3), 331-338. https://doi.org/10.1016/0304-4165(95)00052-D