Figure 5.
Kinetics of cyclooxygenase inhibition by aspirin in wild-type PGHS-2 and the Y504F and Y348F/Y504F mutants. The initial velocity of oxygen consumption was measured after preincubation of PGHS-2 (A), the Y504F mutant (B), or the Y348F/Y504F mutant (C) with the indicated levels of aspirin for the indicated times. Data shown are the averages of triplicate measurements, normalized to the uninhibited control; standard deviations are indicated by error bars. Lines represent exponential or linear fits to the data.