Table 3.
Steady-state and key transient-state kinetic parameters of mouse M5BHMM in comparison with previously characterized class-5 myosins
Numbering of the transient-state kinetic constants refers to Fig. 1B. ND, not determined.
| Parameter | Signal or calculationa | Mm M5BHMM | Mm/Gg M5AHMM (80, 81) | Hs M5CHMM (15) | Dm M5HMM (47) |
|---|---|---|---|---|---|
| Steady-state ATPase | |||||
| kbasal (s−1) | NADH assay | 0.12 ± 0.02 | ND | ND | ND |
| kcat (s−1) | NADH assay | 7.91 ± 0.15 | 3.8 ± 0.6 | 2.31 ± 0.55 | 12.6 ± 0.5 |
| Kapp (μm) | NADH assay | 3.12 ± 0.26 | 0.15 ± 0.06 | 5.1 ± 1.8 | 10.8 ± 1.2 |
| kcat/Kapp (μm−1 s−1) | NADH assay | ∼2.5 | ∼25 | ∼0.45 | ∼1.2 |
| ADP interaction | |||||
| k−D,HMM (s−1) | ADPb | 19.53 ± 0.25 | ND | ND | ND |
| k−AD,HMM,fast (s−1) | Light scatteringb | 7.24 ± 0.1 | 42 ± 9 | 5.5 ± 0.2 | ND |
| k−AD,HMM,slow (s−1) | Light scatteringb | 1.27 ± 0.02 | ND | 0.026 ± 0.9 | ND |
a In this study.
b From chasing experiment.