Steady-state actin-activated ATPase measurements
| Construct . | v0 (s−1) (± SD) . | ATPase @ 60 µM actin (s−1) (± SD) . | KATPase (µM) (± SE) . | kcat (s−1) (± SE) . |
|---|---|---|---|---|
| WT S1, n = 3 | 0.02 ± 0.01 | 3.8 ± 0.2 | 26.5 ± 5.6 | 5.7 ± 0.5 |
| WT 2HEP, n = 4 | 0.03 ± 0.03 | 3.4 ± 1.0 | 23.4 ± 11.5 | 4.7 ± 1.0 |
| WT 15HEP, n = 5 | 0.02 ± 0.02 | 0.4 ± 0.1 | 99.9 ± 64.5 | 1.1 ± 0.5 |
| WT 25HEP, n = 4 | 0.03 ± 0.02 | 0.6 ± 0.3 | ND | ND |
| E525K S1, n = 3 | 0.04 ± 0.01 | 9.9 ± 1.4** | 1.5 ± 0.6* | 11.3 ± 0.5** |
| E525K 2HEP, n = 3 | 0.03 ± 0.04 | 9.4 ± 0.3** | 2.2 ± 0.8 | 9.5 ± 0.5* |
| E525K 15HEP, n = 3 | 0.01 ± 0.02 | 0.2 ± 0.1* | 53.3 ± 20.8 | 0.4 ± 0.1 |
| E525K 25HEP, n = 4 | 0.02 ± 0.02 | 0.7 ± 0.2 | ND | ND |
| Construct . | v0 (s−1) (± SD) . | ATPase @ 60 µM actin (s−1) (± SD) . | KATPase (µM) (± SE) . | kcat (s−1) (± SE) . |
|---|---|---|---|---|
| WT S1, n = 3 | 0.02 ± 0.01 | 3.8 ± 0.2 | 26.5 ± 5.6 | 5.7 ± 0.5 |
| WT 2HEP, n = 4 | 0.03 ± 0.03 | 3.4 ± 1.0 | 23.4 ± 11.5 | 4.7 ± 1.0 |
| WT 15HEP, n = 5 | 0.02 ± 0.02 | 0.4 ± 0.1 | 99.9 ± 64.5 | 1.1 ± 0.5 |
| WT 25HEP, n = 4 | 0.03 ± 0.02 | 0.6 ± 0.3 | ND | ND |
| E525K S1, n = 3 | 0.04 ± 0.01 | 9.9 ± 1.4** | 1.5 ± 0.6* | 11.3 ± 0.5** |
| E525K 2HEP, n = 3 | 0.03 ± 0.04 | 9.4 ± 0.3** | 2.2 ± 0.8 | 9.5 ± 0.5* |
| E525K 15HEP, n = 3 | 0.01 ± 0.02 | 0.2 ± 0.1* | 53.3 ± 20.8 | 0.4 ± 0.1 |
| E525K 25HEP, n = 4 | 0.02 ± 0.02 | 0.7 ± 0.2 | ND | ND |
*P < 0.05 or **P < 0.005 for comparison of E525K and WT, see Tables S1 and S2. The v0 and ATPase at 60 µM actin represent the mean (± SD) from n preparations. The KATPase and kcat are reported as ± SE from the fits of the data in Fig. 3.