Fig. 5.
Effect of NS398 on kinetics of COX inactivation by aspirin in PGHS-1 wildtype (WT) and R108Q variant. Each enzyme was preincubated with 1.0 mM aspirin and the indicated levels of NS-398 for varying lengths of time to determine apparent rate constants (k2’) for loss of COX activity. The k2’ vs. [NS-398] data from each experiment were analyzed to estimate IC50 values as described in Methods. The IC50 values shown are averages ± SD from 3-4 experiments.