Interaction of echicetin with a high affinity thrombin binding site on platelet glycoprotein GPIb.
Echicetin, a protein isolated from Echis carinatus snake venom, inhibited platelet aggregation and secretion induced by low concentrations of thrombin ( < 0.2 U/ml), by binding to platelet glycoprotein Ib (GPIb). The inhibition was not observed when the platelets were stimulated with higher concentrations of thrombin ( > 0.2 U/ml). Echicetin competed with thrombin for binding to the high affinity site on GPIb. Thrombin also inhibited 50% of the binding of 125I-echicetin to the platelets.
Peng
M
M
Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Emig
F A
FA
Mao
A
A
Lu
W
W
Kirby
E P
EP
Niewiarowski
S
S
Kowalska
M A
MA
D000595:Amino Acid Sequence; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002352:Carrier Proteins; D000939:Epitopes; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000097:blood; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D011506:Proteins / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D018179:Receptors, Thrombin / Q000378:metabolism*; D012636:Secretory Rate / Q000187:drug effects; D013917:Thrombin / Q000494:pharmacology; D014757:Viper Venoms / Q000097:blood / Q000494:pharmacology*
D002352:Carrier Proteins; D000939:Epitopes; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D019038:Platelet Glycoprotein GPIb-IX Complex; D010980:Platelet Membrane Glycoproteins; D011506:Proteins; D011956:Receptors, Cell Surface; D018179:Receptors, Thrombin; D014757:Viper Venoms; C028254:von Willebrand factor receptor; C080995:echicetin; D013917:Thrombin