Structure-Based Design of Potent, Amidine-Derived Inhibitors of Factor Xa: Evaluation of Selectivity, Anticoagulant Activity, and Antithrombotic Activity
摘要:
To enhance the potency of 1,2-dibenzamidobenzene-derived inhibitors of factor Xa (fXa), an amidine substituent was incorporated on one of the benzoyl side chains to interact with Asp189 in the S1 specificity pocket. Lead molecule 1 was docked into the active site of Ma to facilitate inhibitor design. Subsequently, iterative SAR studies and molecular modeling led to a 1000-fold increase in Ma affinity and a refined model of the new inhibitors in the Ma active site. Strong support for the computational model was achieved through the acquisition of an X-ray crystal structure using thrombin as a surrogate protein. The amidines in this series show high levels of selectivity for the inhibition of Ma relative to other trypsin-like serine proteases. Furthermore, the Ma affinity of compounds in this series (K-ass = 50-500 x 10(6) L/mol) translates effectively into both anticoagulant activity in vitro and antithrombotic activity in vivo.