Table 2. Tilt Angles τ (°) and Azimuthal Rotation Angles ρ (°) Obtained from the Refined NMR Structures (NMRr) and MD Simulations and Depth of Insertion z (Å) from MD for the N- (residues 3–10) and C- (residues 14–20) Helical Segments of Each Peptidea.
| residues 3 to 10 |
residues 14 to 20 |
kink |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| NMRr | MD |
NMRr | MD |
NMRr | MD |
||||
| avg | avg | rmsf | avg | avg | rmsf | avg | avg | rmsf | |
| τN | τC | Δτ = (τN – τC) | |||||||
| p1 PC/PG | 90 (2) | 91 (1) | 7 | 86 (1) | 87 (2) | 9 | 4 (2) | 5 (1) | 8 |
| p3 PC/PG | 91 (1) | 93 (2) | 7 | 84 (1) | 85 (2) | 8 | 7 (2) | 7 (1) | 8 |
| p1 PE/PG | 83 (3) | 92 (2) | 8 | 86 (1) | 90 (2) | 9 | –3 (3) | 2 (1) | 7 |
| p3 PE/PG | 92 (1) | 93 (2) | 7 | 83 (2) | 86 (2) | 8 | 9 (3) | 7 (1) | 7 |
| ρN | ρC | Δρ = (ρN – ρC) | |||||||
| p1 PC/PG | 246 (3) | 265 (3) | 11 | 213 (1) | 245 (3) | 13 | 33 (4) | 21 (1) | 8 |
| p3 PC/PG | 236 (2) | 245 (3) | 11 | 215 (2) | 225 (3) | 11 | 20 (2) | 20 (1) | 8 |
| p1 PE/PG | 253 (2) | 256 (3) | 13 | 218 (2) | 236 (3) | 12 | 35 (4) | 20 (1) | 8 |
| p3 PE/PG | 250 (2) | 241 (3) | 11 | 220 (2) | 223 (2) | 10 | 30 (3) | 18 (1) | 8 |
| zN | zC | Δz = (zN – zC) | |||||||
| p1 PC/PG | – | 3.4 (0.1) | 0.8 | – | 3.3 (0.1) | 0.8 | 1.7 (0.1) | 0.1 (0.3) | 1.3 |
| p3 PC/PG | – | 3.7 (0.1) | 0.9 | – | 3.4 (0.1) | 0.9 | 2.2 (0.1) | 0.3 (0.3) | 1.4 |
| p1 PE/PG | – | 1.0 (0.1) | 0.8 | – | 1.4 (0.1) | 0.8 | 0.9 (0.1) | –0.4 (0.4) | 1.6 |
| p3 PE/PG | – | 2.4 (0.1) | 0.9 | – | 2.3 (0.1) | 0.9 | 1.6 (0.1) | 0.1 (0.4) | 1.5 |
a
To characterize the kink, differences in tilt (Δτ), azimuthal rotation (Δρ), and depth (Δz) between the N- and C-segments are also provided. For each system, the uncertainties indicated in parentheses by the NMRr and MD angles correspond to standard deviations among the top 10 NMR structures and SE of the MD data calculated from 10 ns blocks, respectively. The rmsf from MD are also included.