Thromb Haemost 1998; 79(06): 1199-1207
DOI: 10.1055/s-0037-1615040
Rapid Communication
Schattauer GmbH

The cDNA Cloning and Molecular Characterization of a Snake Venom Platelet Glycoprotein Ib-binding Protein, Mamushigin, from Agkistrodon halys blomhoffii Venom[*]

Authors

  • Yoshihiko Sakurai

    1   From the Departments of Pediatrics and Blood Transfusion Medicine, Nara Medical University, Kashihara, Nara
  • Yoshihiro Fujimura

    1   From the Departments of Pediatrics and Blood Transfusion Medicine, Nara Medical University, Kashihara, Nara
  • Tetsuro Kokubo

    2   Division of Gene Function in Animals, Nara Institute of Science and Technology, Takayama, Ikoma, Nara
  • Kouji Imamura

    2   Division of Gene Function in Animals, Nara Institute of Science and Technology, Takayama, Ikoma, Nara
  • Tomihisa Kawasaki

  • Makoto Handa

    4   Blood Transfusion Center, Keio University School of Medicine, Shinjyuku, Tokyo
  • Masami Suzuki

    5   Institute for Comprehensive Medical Science, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
  • Taei Matsui

    5   Institute for Comprehensive Medical Science, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
  • Koiti Titani

    5   Institute for Comprehensive Medical Science, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
  • Akira Yoshioka

    1   From the Departments of Pediatrics and Blood Transfusion Medicine, Nara Medical University, Kashihara, Nara
Weitere Informationen

Publikationsverlauf

Received 24. September 1997

Accepted after revision 25. Februar 1998

Publikationsdatum:
07. Dezember 2017 (online)

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Summary

The entire cDNA sequences of a novel snake venom platelet glyco-protein (GP) Ib-binding protein (BP) composed of an α/β heterodimeric structure, termed mamushigin, from Agkistrodon halys blomhoffii were determined, that include the leader peptides (21/23 amino acid residues) and mature subunits (136/123 amino acid residues). The mature subunits of mamushigin are 37.5% identical, and showed a high degree of similarity (37.7-67.5% identity) with the respective subunits of group VII C-type lectins (19). The sequences of the leader peptides of the mamusigin subunits showed the highest similarity (α-73.9/ β-82.6%) with those of factor IX/X-BP from Trimeresurus flavoviridis, and the cleavage site residue in both proteins was the same Ala–1.

The GPIb-binding specificity of mamushigin is strongly supported by several lines of evidence, but mamushigin can directly aggregate normal platelets, similar to alboaggregin-B (AL-B) (1). This differs from other GPIb-BP’s. In mamushigin-treated platelets, serotonin was not released, and flow cytometric analysis using a monoclonal antibody PAC-1 totally excluded platelet GPIIb/IIIa activation. Mamushigin enhanced platelet aggregation at low-shear stress, and this effect totally disappeared in the presence of GPIb-receptor blockers specific for von Willebrand factor binding, but not by GPIIb/IIIa-receptor blockers. At high-shear stress, mamushigin blocked platelet aggregation in a dose-dependent manner, as seen with other GPIb-BP’s. This paper, therefore, describes the cDNA cloning and molecular characterization of mamushigin which has a different effect on platelet aggregation under different shear stress.

* This work was supported in part by a Research Grant (8A-1) for Cardiovascular Diseases to Yoshihiro Fujimura from the Japanese Ministry of Health and Welfare, and by Grants-in-Aid to Koiti Titani from the Fujita Health University and the Uehara Memorial Foundation.