Triflavin, an antiplatelet Arg-Gly-Asp-containing peptide, is a specific antagonist of platelet membrane glycoprotein IIB-IIIA complex

Tur Fu Huang, Joen Rong Sheu, Che Ming Teng, Shun Wen Chen, Chen Sheng Liu

研究成果: 雜誌貢獻文章同行評審

75 引文 斯高帕斯(Scopus)

摘要

Triflavin, an antiplatelet peptide containing Arg-Gly-Asp, purified from Trimeresurus Aavoviridis venom, inhibits aggregation of human platelets stimulated by a variety of agonists. It blocks aggregation through interference with fibrinogen binding to its specific receptor on the platelet surface membrane in a competitive manner, but it has no apparent effect on intracellular events, such as thromboxane B2 formation, phosphoinositides breakdown and intracellular Ca2+ mobilization of thrombin-activated platelets. In this study, we determined the complete sequence of triflavin, which is composed of a single polypeptide chain of 70 amino acids. Its sequence is rich in cysteine and contains Arg-Gly-Asp at residues 49-51 in the carboxy-tenninal domain. Triflavin shows about 68% identity of amino acid sequence with trigramin, which is a specific antagonist of the fibrinogen receptor associated with glycoprotein Ilb/IIIa complex. [125I]Triflavin binds to unstimulated and ADP-stimulated platelets in a saturable manner and its Kd values are estimated to be 76 and 74 nM, respectively; the corresponding numbers of binding sites are 31,029 and 34,863 per platelet, respectively. [125I]Triflavin binding is blocked by Gly-Arg-Gly-Asp-Ser in a competitive manner. EDTA, the Arg-Gly-Asp-containing peptides (including naturally occurring polypeptides, trigramin and rhodostomin), and monoclonal antibody, 7E3, raised against GP IIb/IIIa complex, inhibit [125I]triflavin binding to unstimulated and ADP-stimulated human platelets. In conclusion, triflavin specifically binds to fibrinogen receptor associated with GP IIb/IIIa complex and its binding site is located at or near GP Ilb/IIIa complex, overlapping with those of 7E3 and another Arg-Gly-Asp-containing polypeptide, rhodostomin. The Arg-Gly-Asp sequence of triflavin plays an important role in mediating the binding of triflavin towards GP IIb/IIIa complex.

原文英語
頁(從 - 到)328-334
頁數7
期刊Journal of Biochemistry
109
發行號2
出版狀態已發佈 - 2月 1991

ASJC Scopus subject areas

  • 分子生物學
  • 生物化學

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