Table 1. Structural statistics for the S64 and S67 ensembles.
| S64 | S67 | |||
| Physical Parameters (including nonnative N-terminal residue) | ||||
| Number of residues | 32 | 36 | ||
| Average molecular weight (reduced, unlabeled, Da) | 3565.98 | 4249.82 | ||
| Monoisotopic molecular weight (reduced, unlabeled, Da) | 3563.40 | 4246.85 | ||
| Structural Restraints | ||||
| NOE-derived distance restrains (ARIA cycle 8) | ||||
| Intraresidue (|i – j| = 0) | 209 | 319 | ||
| Sequential (|i – j| = 1) | 66 | 94 | ||
| Short (2≤|i – j|≤3) | 9 | 20 | ||
| Medium (4≤|i – j|≤5) | 11 | 23 | ||
| Long (|i – j|>5) | 34 | 83 | ||
| Ambiguous | 84 | 137 | ||
| Total | 413 | 676 | ||
| Dihedral constraints | ||||
| Phi | 24 | 25 | ||
| Psi | 24 | 25 | ||
| Sγ-Sγ distance restraints | 3 | 3 | ||
| Hydrogen bond restraints | 0 | 7 | ||
| Statistics for accepted structures | ||||
| Accepted structures | 20 | 20 | ||
| Mean CNS energy terms | ||||
| E total (kcal mol–1 ± SD) | −786 (±41) | −714 (±47) | ||
| E van der Waals (kcal mol–1 ± SD) | −100 (±49) | −126 (±10) | ||
| E distance restraints (kcal mol–1 ± SD) | 183 (±15) | 294 (±21) | ||
| Restraint violations >0.3 Å (average # per structure) | 5.6 (±1.7) | 5.7 (±2.5) | ||
| RMS deviations from the ideal geometry used within CNS | ||||
| Bond lengths (Å) | 0.0040 | 0.0043 | ||
| Bond angles (°) | 0.55 | 0.64 | ||
| Improper angles (°) | 1.86 | 3.00 | ||
| Ramachandran Statistics (PROCHECK 3.5.4 [37]) | ||||
| Most favored (%) | 88.5 | 68.6 | ||
| Additionally allowed (%) | 10.8 | 25.9 | ||
| Generously allowed (%) | 0.42 | 1.07 | ||
| Disallowed (%) | 0.21 | 4.47 | ||
| Average atomic RMS deviations from average structure (±SD)* | ||||
| N, Cα, C, and O atoms (all residues, Å) | 0.86 (±0.22) | 0.87 (±0.33) | ||
| All heavy atoms (all residues, Å) | 1.43 (±0.21) | 1.33 (±0.16) | ||
| N, Cα, C, and O atoms (for residues with cop ≥0.9, Å) | 0.57 (±0.17) | 0.33 (±0.08) | ||
| All heavy atoms (for residues with cop ≥0.9, Å) | 1.30 (±0.17) | 1.04 (±0.14) | ||
| MolProbity analyses (v3.19 [38]) | ||||
| Clashscore | 12 (±4) | 18.7 (±5.4) | ||
| Clashscore percentile (%) | 63 (±18) | 39 (±19) | ||
| Clashscore Z-score | 0.42 (±0.62) | −0.25 (±0.48) | ||
*
Two sets of atomic RMS deviations are provided. The first set is for the full peptide (residues 1–32 for S64, 1–36 for S67) whereas the second set is calculated only including residues for which the circular order parameters (cop) for both φ and ψ are ≥0.9 (residues 2 and 4–30 for S64, and residues 5–35 for S67).