Utako OKAMOTO

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A short history of the research work of S. Okamoto and co-workers, for the previous 50 years, is briefly described. In the 1950s, when the physiologic role of fibrinolysis had not been established, they began to seek for compounds that inhibit the action of plasmin. They examined approximately 200 lysine derivatives and discovered epsilon aminocaproic acid(More)
also had found an antifibrinolytically active isomer of AMCHA , but they reserved in deciding its molecular shape. In fact , it seemed that their results tempted them to regard the active isomer as a cis-form . instead of tra.ns-form Accordingly, the authors understand that the antifibrinolytic activity of trans-AMCHA was claimed solely by our group . The(More)
During the course of the development of active center-directed plasmin inhibitors, it was found that N-(trans-4-aminomethylcyclohexanecarbonyl)-lysine-4-methoxycarb onylanilide inhibited plasma kallikrein more potently than other enzymes such as plasmin, urokinase, and thrombin, although the inhibitory activity was not as potent and enzyme selectivity not(More)
This paper deals with a comparative aspect of the fibrinolytic system in man and rabbit, particularly relating to the "proactivator-like component" in rabbit plasma whose behavior is similar to proactivator A of human plasma fractionated by gel filtration and apparently acts as proactivator in the presence of a small amount of human globulin. The entity of(More)
Human plasma: Dried human plasma (Nihon Seiyaku Co., Ltd.) was used. Commercial preparations of fibrinogen (Cohn's Fraction I, Armour Labora tory), thrombin (Mochida Co.) and streptokinase (Varidase, Lederle Lab. of American Cyamid Co.) were used in the following experiments. Plasminogen (Kline's preparation) was kindly donated by A .B. KABI. Urea solution(More)
Based on structure-activity relationship studies, we designed and synthesized plasmin (PL) and plasma kallikrein (PK) inhibitors. Trans-(4-aminomethylcyclohexanecarbonyl)-Tyr(O-Pic)-octylamide inhibited PL, PK, urokinase (UK) and thrombin (TH) with IC50 values of 0.53, 30, 5.3 and > 400 microm, respectively.(More)
Based on the structure of Tra-Tyr(O-Pic)-octylamide, a portion of the octylamine was replaced with moieties bearing hydrophobic, basic or acidic groups. Replacement of the C-terminal residue with a moiety bearing a hydrophobic group gave the proper affinity of the inhibitor to both plasmin (PL) and plasma kallikrein (PK). While addition of a basic residue(More)