Mechanism of inhibition of novel COX-2 inhibitors.

Abstract

Rome and Lands (1975) demonstrated that certain nonsteroidal anti-inflammatory drugs (NSAIDs), exemplified by indomethacin, displayed time dependent inhibition of cyclooxygenase (COX) and that this type of time dependent inhibition is consistent with a two step model. The first step in this model represents the association of enzyme and inhibitor to form a rapidly reversible complex. The second step represents formation of an extremely tight, non-covalent complex that is only slowly reversible. With the recognition of distinct isoforms, it has also been established that COX-2 selective inhibitors are time dependent inhibitors of COX-2, but not of COX-1. This difference in mechanism of inhibition of COX-1 and COX-2 is the basis for their selectivity (Copeland et al., 1994). Time dependence of COX-2 selective inhibitors has been correlated to the presence of a side pocket present in the active site of COX-2 but not COX-1 (Gierse et al., 1996).KeywordsTime Dependent BehaviorSteady State MeasurementSulfonamide MoietyHalf Maximal InhibitionTime Dependent InhibitionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.