Table 1.
Summary of unitary mechanical parameters
| Myosin type | d, nm | ton†, ms | F, pN | ton‡, ms |
|---|---|---|---|---|
| Smooth 2HD | 9.2 ± 0.5 (14) | 167 ± 23 (14) | 1.5 ± 0.1 (6) | 284 ± 54 (5) |
| Smooth 1HD | 5.7 ± 0.3* (18) | 150 ± 19 (14) | 0.6 ± 0.1* (9) | 263 ± 49 (8) |
| Skeletal 2HD | 11.6 ± 0.7 (10) | 48 ± 2 (2) | 1.3 ± 0.1 (11) | 166 ± 25 (7) |
| Skeletal 1HD | 6.8 ± 0.6* (14) | 44 ± 7 (11) | 0.8 ± 0.1* (20) | 149 ± 52 (6) |
Data are presented as the mean ± SEM. The quantities in parentheses represent the number of MV histograms contributing to the mean. 1HD, single-headed; 2HD, double-headed.
*
P < 0.05 vs. 2HD.
†
Unloaded ton for displacement data collected at 10 μM ATP.
‡
Loaded ton for force data collected at 10 μM for smooth-muscle myosin and 1 μM ATP for skeletal-muscle myosin.