Table 1.
Solid-state NMR and refinement statistics for protein structures
| Best-fit model (Fig. 3) | Ensemble of 10 models (Fig. S3) | |
|---|---|---|
| NMR distance and dihedral constraintsa | ||
| Total constraints | 78 | 78 |
| Distance constraints | ||
| Total distance constraints | 40 | 40 |
| Intra-residueb | – | – |
| Inter-residue | 40 | 40 |
| Sequential (|i – j| = 1)b | ||
| Medium-range (2≤|i – j| ≤ 4) | – | – |
| Long-range (|i – j| ≥ 5) | 11 | 11 |
| Intermolecular | 2 | 2 |
| Hydrogen bonds | – | – |
| Unobserved long-range contact constraintsc | 27 | 27 |
| Total dihedral angle constraints | 38 | 38 |
| ϕ | 19 | 19 |
| ψ | 19 | 19 |
| Structure statistics | ||
| Violations (mean ± s.d.) | ||
| Distance constraints (Å) | 0.007 ± 0.050 | 0.011 ± 0.073 |
| Dihedral angle constraints (°) | 0.04 ± 0.13 | 0.05 ± 0.97 |
| Max. dihedral angle violation (°) | 0.90 | 67.63 |
| Max. distance constraint violation (Å) | 0.500 | 1.040 |
| Deviations from idealized geometry | ||
| Bond lengths (Å) | 0.014 | 0.014 |
| Bond angles (°) | 2.10 | 2.10 |
| Average r.m.s. deviation from mean structure (Å)d | ||
| Heavy | N/A | 1.53 |
| Backbone | N/A | 1.08 |
a
Only includes experiment-based constraints per Aβ molecule. Constraints related to the molecular symmetry were excluded.
b
Intra-residue contacts were observed as listed in Supplementary Table 2, but not included in the structural calculations.
c
Only side-chain contacts were used for well ordered residues for which strong intra-residue cross peaks were observed.
d
The RMSD was calculated for the central 4 Aβ molecules in the 12-mer model.