Table 1. Comparison of kinetic parameters for MuSK, CAM-1, ROR1 and ROR2 tyrosine phosphorylation activity.
| Kinase | KM(peptide) | KM(ATP) | Kcat | Kcat/KM(ATP) |
| (mM) | (mM) | (min−1) | (min−1mM−1) | |
| MuSK, Unphosphorylateda | 1.58±0.24 | 3.40±0.27 | 0.47±0.03 | 0.14 |
| MuSK, Phosphorylateda | 0.68±0.07 | 0.38±0.12 | 108.0±0.1 | 284 |
| CAM-1, Unphosphorylated, Mg2+ | >5 | 3.53±0.34 | 2.63±0.11 | 0.75 |
| CAM-1, Unphosphorylated, Mn2+ | ND | 0.45±0.09 | 2.46±0.16 | 5.47 |
| CAM-1, Phosphorylated, Mg2+ | >5 | 3.35±0.57 | 2.53±0.18 | 0.76 |
| CAM-1, Phosphorylated, Mn2+ | ND | 0.63±0.07 | 2.64±0.10 | 4.19 |
| CAM-1 K624R, Mg2+ | ND | 6.69±1.12 | 0.20±0.02 | 0.03 |
| CAM-1 K624R, Mn2+ | ND | 0.74±0.18 | 0.51±0.04 | 0.69 |
| CAM-1 D744N, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
| CAM-1 G599C, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
| CAM-1 G599D, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
| ROR1, Mg2+ or Mn2+ | >5 | >15 | <0.0005 | <0.00003 |
| ROR1 C482G, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
| ROR2, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
| ROR2 D482G, Mg2+ or Mn2+ | ND | >15 | <0.0005 | <0.00003 |
CAM-1 and ROR data were obtained from a [γ−32P]ATP-based phosphocellulose binding assay. Data are from three technical replicates, ± standard error. ND, Not determined. aMuSK data are from [24].