Table 3.
Results of Analytical Ultracentrifugation Analyses
| D124V | Reversible Monomer-Dimer Self- Associating Model |
Non-Interacting Model |
|---|---|---|
| Monomer MW | 16.1 (15.8, 16.4) kDa | 16.8 (16.6, 17.1) kDa |
| Dimer MW | Constrained to 2 × Monomer MW | 31.8 (31.6, 3.23) kDa (unconstrained) |
| Monomer f/f0 | 1.12 (1.09, 1.14) | 1.19 (1.18, 1.20) |
| Dimer f/f0 | 1.29 (1.28, 1.31) | 1.31 (1.30, 1.31) |
| K Dissociation | 0.65 µM (0.49 µM, 0.96 µM) | 0.66 µM (based on partial concentrations) |
| Koff rate const. | 1.03 × 10−4 (0.96 × 10−4, 1.11 × 10−4) s−1 | n/a |
| Kon rate const. | 6.69 × 10−5 M s−1 | n/a |
| H80R | ||
| Monomer MW | 16.9 (16.8, 17.0) kDa | 29.1 (26.9, 29.7) kDa * |
| Dimer MW | Constrained to 2 × Monomer MW | 30.6 (30.1, 32.8) kDa (unconstrained) |
| Monomer f/f0 | * | 1.0 (1.0, 1.0) |
| Dimer f/f0 | 1.32 (1.31, 1.32) | 1.27 (1.25, 1.36) |
| K Dissociation | 0.143 µM (0.142 µM, 0.144 µM) | * |
| Koff rate const. | * | n/a |
| Kon rate const. | * | n/a |
Fitting parameters for the freshly isolated mutant D124V and H80R SOD1 samples. Values in parenthesis represent 95% confidence intervals determined in the Monte Carlo analysis. Both the reversible self-association model and the non-interacting models give very similar results, and are fitted equally well to the data.
*
The second species determined in this fit did not correspond to the monomer molecular weight, and therefore equilibrium constant cannot be calculated.