Table 1.
Kinetic parameters for inhibition of COX-1 and COX-2 enzymatic activities
| COX-1 | COX-2 | |||||
|---|---|---|---|---|---|---|
| Ki (μM) | kon (s−1 μM–1) | t1/2 (min) | Ki (μM) | kon (s−1 μM−1) | t1/2 (min) | |
| Lumiracoxib | 3.2 (4.3, 2.0) | >105 (>105, >105) | ≪1 (≪1, ≪1) | 0.06 (0.05, 0.07) | 0.005 (0.004, 0.006) | 42 (48, 36) |
| Diclofenac | 0.01 (0.01, 0.01) | 0.1 (0.1, 0.1) | 6 (6, 6.1) | 0.01 (0.01, 0.01) | 0.006 (0.006, 0.006) | 152 (154, 150) |
| Celecoxib | 15 (16, 14) | >105 (>105, >105) | ≪1 (≪1, ≪1) | 0.20 (0.13, 0.26) | 0.01 (0.01, 0.01) | 5.1 (6.2, 4.0) |
Purified preparations of ovine COX-1 and human recombinant COX-2 were pretreated with compounds for varying time periods (0–60 min). Changes in the optimal velocity of O2 consumption were measured following the addition of the substrate arachidonic acid (20 μM). Kinetic parameters were calculated as described in Methods section.
The results are presented as the average of two experiments (the first value), and the results of each individual experiment (the values in parentheses).