Table 3 Mean stabilization energy (E(2)) of the corresponding n(O)/σ(CO)/π(CO)→σ*(NH/CαHα) electron delocalization for each CO···HN, CO···HαCα front, CO···HαCα inner and CO···HαCα outer H-bond/interaction between PPII helices in the different interfaces at the M06-2X/6-31 + G(d) level of theory
From: Hydrogen bonding patterns and cooperativity in polyproline II helical bundles
E(2) (kcal·mol−1) | Interface | Number of PPII Helices | |||
|---|---|---|---|---|---|
2 | 3 | 4 | 5 | ||
CO···HN | ab | 16.350 | 16.558 | 16.590 | 16.605 |
bc | - | 21.525 | 21.793 | 21.833 | |
cd | - | - | 21.548 | 21.825 | |
CO···HαCα Front | ab | 1.405 | 1.423 | 1.430 | 1.430 |
bc | - | 1.293 | 1.310 | 1.318 | |
cd | - | - | 1.788 | 1.815 | |
CO···HαCα Inner | ab | 5.783 | 5.840 | 5.837 | 5.837 |
bc | - | 6.690 | 6.743 | 6.740 | |
cd | - | - | 6.450 | 6.527 | |
CO···HαCα Outer | ab | 0.293 | 0.287 | 0.287 | 0.287 |
bc | - | 0.180 | 0.173 | 0.173 | |
cd | - | - | 0.213 | 0.210 | |
