Table 1. Hsp90-client affinities determined by fluorescence anisotropy using labeled clients and unlabeled Hsp90 in different nucleotide states.
Values correspond to the average of three independent experiments and the error to the SD. The column at the right shows theoretical fractions of complexes on our standard NMR conditions (100 μM 2:2 stoichiometric mixture) based on the experimentally determined dissociation constant (KD) values.
| Client |
Hsp90
nucleotide state |
KD (μM) |
Theoretical %
complex |
| GR-LBD (16) | Apo | 2.8 ± 0.23 | 84 |
| ATP | 0.9 ± 0.11 | 91 | |
| AMP-PNP | 4.3 ± 0.28 | 81 | |
| ATPγS | 1.4 ± 0.11 | 88 | |
| MR-LBD | Apo | 5.7 ± 0.38 | 79 |
| ATP | 5.3 ± 0.58 | 80 | |
| AMP-PNP | 2.2 ± 0.25 | 86 | |
| ATPγS | 1.9 ± 0.06 | 87 | |
| P53-DBD | Apo | 5.3 ± 0.3 | 79 |
| ATP | 4.4 ± 0.21 | 81 | |
| AMP-PNP | 5.5 ± 0.25 | 79 | |
| ATPγS | 5.3 ± 0.25 | 79 | |
| Tau (isoform D) | Apo | 5.3 ± 0.65 | 81 |
| ATP | 5.0 ± 0.6 | 81 | |
| AMP-PNP | 5.4 ± 0.66 | 80 | |
| ATPγS | 5.5 ± 0.32 | 80 |