[Inducing conformational changes in thrombin by ligands as a way of regulating its activity]

This review summarizes data on changes in thrombin conformation induced by various ligands including hirudin, hirugen, similar acidic peptides, fibrinogen, thrombomodulin, heparin, antithrombin, prothrombin, and platelet receptor. Studies of enzyme kinetics, spectroscopy, X-ray structure, and thermodynamics of thrombin complexes with various ligands indicate that the thrombin molecule undergoes conformational changes. Possible mechanisms of allosteric regulation of thrombin activity by high molecular weight ligands are discussed which can be important during physiologic or pathophysiologic reactions of the organism.