Table 2. Kinetics Parameters for Caspase-6 Variants Demonstrate that Inhibition Is the Result of Steric Clash between S257D and P201.
| Km app(μM) | 10−3 × kcat(S−1) | 10−5 × kcat/Km app(S−1/μM) | |
|---|---|---|---|
| WT | 38 ± 4.3 | 700 ± 20 | 1,800 |
| S257D | 47 ± 2.1 | 1.5 ± 0.2 | 3.2 |
| S257D/R254D | 54 ± 3.9 | 17 ± 1 | 32 |
| S257D/R254A | 37 ± 1.2 | 2.3 ± 0.1 | 6.2 |
| S257D/R259E | 43 ± 2.1 | 4.5 ± 0.3 | 10 |
| S257D/R259A | 28 ± 0.2 | 2.1 ± 0.2 | 7.5 |
| S257D/K272A | 41 ± 0.2 | 2.3 ± 0.1 | 5.6 |
| S257D/K273A | 37 ± 3.6 | 5.1 ± 0.1 | 13 |
| S257C | 39 ± 1.8 | 700 ± 30 | 1,800 |
| S257N | 72 ± 4.0 | 3.5 ± 0.1 | 4.9 |
| S257W | 31 ± 2.8 | 0.62 ± 0.03 | 2.0 |
| S257D/P201G | 35 ± 3.0 | 100 ± 30 | 290 |
Substrate titrations to assess Km app and kcat were measured from independent duplicate dilutions of substrate on 3 separate days.