Characterization of cell binding and thrombin inhibitory regions on kininogens' heavy chain.
Investigations have been performed to determine the domain(s) on kininogens' heavy chain that binds to platelets and contains thrombin inhibitory region Domain 3, but not domains 1 or 2, completely inhibited 125I-HK binding to platelets (Ki = 24 nM +/- 7, n = 4). D3 binding to platelets was saturable with an apparent Kd of 39 nM +/- 8 (n = 4) and 1227 +/- 404 binding sites/platelet. D3 inhibited 125I-thrombin binding to platelets which prevented thrombin-induced platelet aggregation and secretion. These studies indicate that D3 on kininogens' heavy chain contains a cell binding region and another region which inhibits thrombin binding and activation of platelets.
Jiang
Y P
YP
Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA 19140.
Schmaier
A H
AH
D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D001792:Blood Platelets / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D007704:Kininogens / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D008969:Molecular Sequence Data; D015539:Platelet Activation / Q000187:drug effects; D013917:Thrombin / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D007704:Kininogens; D013917:Thrombin