title: Characterization of cell binding and thrombin inhibitory regions on kininogens' heavy chain.
abstract: 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.
authors: Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA 19140.
authors: Y P
authors: YP
authors: Jiang
authors: A H
authors: AH
authors: Schmaier
mesh_terms: 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
chemical_list: D007704:Kininogens; D013917:Thrombin