TABLE 3:
ATPase and in vitro motility values for wild-type control (PwMhc2) and FSS mutant myosins.
| Myosin isoform (n for ATPase/motility) | Ca-ATPase (s-1) | Basal Mg-ATPase (s-1) | Actin-stimulated Vmax (s-1) | Actin-stimulated Km (µM) | Catalytic efficiency (s-1/µM) | Motility (µm/s) |
|---|---|---|---|---|---|---|
| PwMhc2 (n = 14/14) | 14.57 ± 2.46 | 0.24 ± 0.09 | 1.74 ± 0.37 | 0.54 ± 0.16 | 3.48 ± 0.19 | 5.08 ± 0.73 |
| Y583S (n = 6/5) | 10.16 ± 2.09** | 0.32 ± 0.10 | 1.14 ± 0.26** | 0.35 ± 0.14* | 3.44 ± 0.33 | 3.25 ± 0.41*** |
| T178I (n = 7/4) | 3.15 ± 0.99*** | 0.54 ± 0.14*** | 0.63 ± 0.17*** | 0.53 ± 0.24 | 1.46 ± 0.32*** | 2.53 ± 0.22*** |
| R672C (n = 5/5) | 9.94 ± 3.18* | 0.13 ± 0.04** | 2.22 ± 0.61 | 1.07 ± 0.33* | 2.16 ± 0.25** | 2.67 ± 0.16*** |
Biological replicates (n values) are composed of two technical replicates for ATPase or at least 30 motile filaments for in vitro motility. Data are shown as mean ± SD. Statistical significance was determined using an unpaired t test with Welch's correction. Significant differences were assumed for p < 0.05 (*p < 0.05, **p < 0.01, ***p < 0.001).