Thrombin, a serine protease, plays a central role in the initiation and propagation of thrombotic events. An extensive search for new thrombin inhibitors was performed, using an unconventional approach. Screening of small basic molecules for binding in the recognition pocket of thrombin led to the discovery of (aminoiminomethy1) piperidine (amidinopiperidine) as a weak, but intrinsically selective, thrombin inhibitor. Elaboration of ...