Triflavin, an RGD-containing antiplatelet peptide, binds to GpIIIa of ADP-stimulated platelets.
Triflavin, an Arg-Gly-Asp-containing snake venom peptide, inhibits platelet aggregation through the blockade of fibrinogen binding to the activated platelets. It binds to fibrinogen receptors associated with the glycoprotein IIb/IIIa complex with a Kd value of 7 x 10(-8) M. In this report, a chemical cross-linking approach was used to further characterize the binding components of triflavin on platelet membrane. 125I-triflavin binding was performed with the aid of a chemical cross-linking reagent, DTSSP. Analysis of the cross-linked products by SDS-PAGE (7.5% gel) and subsequent autoradiogram revealed that 125I-triflavin was cross-linked specifically to a protein with an apparent molecular weight of 1.1 x 10(5), and this reaction was inhibited by GRGDS and excess of non-labeled triflavin. This 110 KDa component was identified to be GpIIIa, recognized by AP3, a mAb against GpIIIa, by immunoblotting technique. These results indicate that the triflavin-binding sites on platelets reside at a site in close proximity to GpIIIa.
Sheu
J R
JR
Pharmacological Institute, College of Medicine, National Taiwan University, Taipei.
Teng
C M
CM
Huang
T F
TF
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000906:Antibodies; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D015153:Blotting, Western; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003435:Crotalid Venoms / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D009842:Oligopeptides; D010455:Peptides / Q000097:blood* / Q000302:isolation & purification; D010975:Platelet Aggregation Inhibitors / Q000097:blood*; D010980:Platelet Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D013388:Succinimides / Q000494:pharmacology
D000906:Antibodies; D003432:Cross-Linking Reagents; D003435:Crotalid Venoms; D046911:Macromolecular Substances; D009842:Oligopeptides; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; D013388:Succinimides; C070025:triflavin; D000244:Adenosine Diphosphate; C047981:arginyl-glycyl-aspartic acid; C035759:3,3'-dithiobis(sulfosuccinimidyl propionate)