Drug | Temperature | GXP | K1 | K2 | K3 | K1K2 | Standard deviation |
---|---|---|---|---|---|---|---|
m −1 | m −2 | ||||||
2 μm tubulin | |||||||
Vinorelbine | 5° | GTP | 7.4 × 104 ± 1.2 | 6.7 × 105 ± 0.7 | 5.0 × 1010 | 0.21-a | |
4.7 × 104 ± 0.7 | 9.1 × 104 ± 3.1 | 4.3 × 105 ± 0.7 | 4.3 × 109 | 0.21-b | |||
Vinflunine | 4.4 × 104 ± 4.31-c | 7.3 × 104 ± 5.0 | 3.2 × 109 | 0.21-a | |||
1.3 × 104 ± 3.1 | 4.9 × 104 ± 16.0 | 6.4 × 104 ± 12.0 | 6.4 × 108 | 0.31-b | |||
Vinorelbine | 15° | 7.7 × 104 ± 1.8 | 1.3 × 106 ± 0.2 | 1.0 × 1011 | 0.51-a | ||
5.4 × 104 ± 0.5 | 1.2 × 105 ± 0.2 | 6.5 × 105 ± 0.5 | 6.5 × 109 | 0.41-b | |||
Vinflunine | 9.7 × 104 ± 3.0 | 1.3 × 105 ± 0.2 | 1.3 × 1010 | 0.11-a | |||
3.9 × 104 ± 0.5 | 4.2 × 104 ± 1.0 | 1.6 × 105 ± 0.2 | 1.6 × 109 | 0.21-b | |||
Vinorelbine | 25° | 1.3 × 105 ± 0.2 | 1.1 × 106 ± 0.8 | 1.4 × 1011 | 0.31-a | ||
1.0 × 105 ± 0.05 | 1.1 × 105 ± 0.1 | 1.1 × 106 ± 0.4 | 1.1 × 1010 | 0.31-b | |||
Vinflunine | 8.8 × 104 ± 2.0 | 3.0 × 105 ± 0.4 | 2.6 × 1010 | 0.21-a | |||
4.9 × 104 ± 0.1 | 6.0 × 104 ± 0.3 | 2.9 × 105 ± 0.1 | 2.9 × 109 | 0.21-b | |||
Vinorelbine | 37° | 1.6 × 105 ± 0.3 | 1.6 × 106 ± 0.1 | 2.6 × 1011 | 0.51-a | ||
1.3 × 105 ± 0.03 | 1.3 × 105 ± 0.06 | 1.7 × 106 ± 0.03 | 1.7 × 1010 | 0.51-b | |||
Vinflunine | 6.4 × 105 ± 1.7 | 3.2 × 105 ± 0.2 | 2.1 × 1011 | 0.21-a | |||
4.6 × 105 ± 0.7 | 5.6 × 104 ± 2.2 | 2.6 × 106 ± 0.4 | 2.6 × 1010 | 0.31-b | |||
4 μm tubulin | |||||||
Vinorelbine | 25° | 1.3 × 105 ± 0.2 | 1.1 × 106 ± 0.07 | 1.4 × 1011 | 0.41-a | ||
9.3 × 104 ± 0.4 | 1.1 × 105 ± 0.1 | 1.0 × 106 ± 0.04 | 1.0 × 1010 | 0.31-b | |||
Vinflunine | 9.6 × 104 ± 1.9 | 2.7 × 105 ± 0.3 | 2.6 × 1010 | 0.31-a | |||
4.8 × 104 ± 0.1 | 5.7 × 104 ± 0.2 | 2.7 × 105 ± 0.04 | 2.7 × 109 | 0.21-b |
↵1-a Data were fit with the ligand-mediated model.
↵1-b Data were fit with the combined ligand-mediated plus-facilitated model, and K4 was constrained to be 1 × 104m−1.
↵1-c Note that the error for these parameters is larger than those found in other data sets. This is most likely due to the low level of spiral formation with this drug, especially at low temperature, and therefore very shallow data curves are fit with the two models. We find that the standard deviations of the fits are equivalent to other data sets and therefore the estimates of binding affinities are useful for comparing data collected under other conditions.