Table 1.
Effect on ATPase activities of dephosphorylated and phosphorylated myosins
| Actin-activated ATPase
|
Myosin ATPase
|
|||||
|---|---|---|---|---|---|---|
| Dephosphorylated myosin
|
Phosphorylated myosin
|
Dephosphorylated myosin
|
||||
| Vmax (-fold) | Km (μM) | Vmax (-fold) | Km (μM) | Vmax (-fold) | Km (μM) | |
| Native MLCK | 4.31 ± 0.89 (6) | 1.14 ± 0.26 (6) | Inhibition (refs. 31, 40) | (∗) | 3.85 (1) | 0.59 (1) |
| 777D/972E fragment | 7.36 ± 0.44 (4) | 1.06 ± 0.20 (4) | No stimulation (2) | No stimulation (2) | 3.70 (1) | 0.67 (1) |
| 816M/972E fragment | No stimulation (2) | No stimulation (2) | NT | NT | NT | NT |
| native Telokin | No stimulation (2) | No stimulation (2) | NT | NT | NT | NT |
| 777D/815S peptide | 3.03 ± 0.22 (3) | 6.93 ± 1.61 (3) | No stimulation (1) | No stimulation (1) | 3.45, 2.70 (2) | 9.70, 3.17 (2) |
| 777D/795M peptide | No stimulation (6) | No stimulation (6) | No stimulation (2) | No stimulation (2) | No stimulation (1) | No stimulation (1) |
| 796A/815S peptide | 3.24 ± 0.48 (5) | 20.0 ± 0.96 (5) | NT | NT | NT | NT |
| 787S/815S peptide | 2.68 ± 0.68 (3) | 15.4 ± 4.57 (3) | NT | NT | NT | NT |
| 7776A/834S peptide | 1.47, 2.94 | 14.7, 37.0 | NT | NT | NT | NT |
| 1M/41P peptide | No stimulation (2) | No stimulation (2) | NT | NT | NT | NT |
The numbers in parentheses refer to the number of experiments. NT, not tested; No stimulation, relative ATPase activities were plotted against the protein (0–5 μM) and peptide (0–0.3 mM) concentrations. When they were within 0.95–1.19-fold for the proteins and 0.90–1.50-fold for the peptides, it was considered no stimulation. ∗, half-maximal inhibition was observed at 0.15–0.20 μM, as described in refs. 31 and 40.