Table II.
Nucleotide Affinities of the Mortalin- and Hsc70-NBDs
| Nucleotide | Protein | Kd (µM) |
|---|---|---|
| ADP-Pi | Hsc70-NBD | 0.029 ± 0.002 |
| Mortalin-NBD | 5.3 ± 0.3 | |
| Mortalin-NBDN64Y/C317R | 16 ± 3 | |
| ADP | Hsc70-NBD | 0.052 ± 0.02 |
| Mortalin-NBD | 620 ± 110 | |
| Mortalin-NBDN64Y/C317R | n.d.b | |
| ATP | Hsc70-NBDT204A | 3.9 ± 0.7 |
| Mortalin-NBDT249A | 29 ± 7 | |
| Mortalin-NBDN64Y/C317R/T249A | n.d.b |
aDissociation constants (Kd) measured by ITC; see Supporting Information Figure S2 for raw ITC data and titration curves.
b
ITC signal too weak/noisy to properly calculate dissociation constants. We estimate that the Kd values are in the millimolar range for these measurements.