Applying Osmotic Stress Reveals Two Modes of Enzyme Inhibition

effect over to pro-ABE I suggesting an influence on development of interexosite communication. As F1.2 is removed and PT2 is activated to thrombin, pro-ABE I and II become more solvent exposed and mature into the functional exosites ABE I and II. HSQC NMR titrations with GpIbalpha (269-286, 15Nlabeled L275, 15N-labeled D277) demonstrate that ligand binding affinity at pro-ABE II / ABE II increases as ProT is converted to PT2 and then thrombin. The final thrombin enzyme effectively accommodates substrates at its serine protease active site and utilizes its mature exosites to regulate several coagulation related activities.