Table 2 Activation barriers (E A) and reaction heats (E R) for transformation from canonical (P B ) to zwitterionic (P C ) proline with presence of water molecules
From: Stabilization of zwitterionic versus canonical proline by water molecules
Reaction paths | E A | E R |
|---|---|---|
One water molecule | ||
P B 1W III → [TS1W III–I ]≠ → P C 1W I | 6.7 | 6.1 |
Two water molecules | ||
P B 2W II → [TS2W II–I ]≠ → P C 2W I | 4.2 | 2.0 |
P B 2W I → [TS2W I–II ]≠ → P C 2W II | 6.1 | 4.3 |
P B 2W VI → [TS2W VI–III ]≠ → P C 2W III | 4.9 | 3.2 |
P B 2W III → [TS2W III–IV ]≠ → P C 2W IV | 6.4 | 6.0 |
P B 2W VII → [TS2W VII–V ]≠ → P C 2W V | 6.2 | 3.8 |
P B 2W V → [TS2W V–VI ] → P C 2W VI | 5.8 | 5.2 |
P B 2W IV → [TS2W IV–VII ]≠ → P C 2W VII | 6.7 | 6.5 |
Three water molecules | ||
P B 3W II → [TS3W II–I ]≠ → P C 3W I | 3.8 | 0.7 |
P B 3W I → [TS3W I–II ] ≠ → P C 3W II | 4.3 | 1.9 |
P B 3W III → [TS3W III–III ] ≠ → P C 3W III | 6.3 | −1.1 |
P B 3W III → [TS3W III–IV ] ≠ → P C 3W IV | 8.6 | 0.7 |
P B 3W IV → [TS3W IV–V ] ≠ → P C 3W V | 2.6 | −1.1 |
Four water molecules | ||
P B 4W I → [TS4W I–I ] ≠ → P C 4W I | 1.9 | −2.6 |
P B 4W II → [TS4W II–I ] ≠ → P C 4W I | 5.8 | −3.4 |
P B 4W II → [TS4W II–III ] ≠ → P C 4W III | 5.3 | −2.4 |
P B 4W III → [TS4W III–IV ] ≠ → P C 4W IV | 2.7 | −2.1 |
Five water molecules | ||
P B 5W I → [TS5W I–I ] ≠ → P C 5W I | 4.2 | −6.0 |
P B 5W II → [TS5W II–II ] ≠ → P C 5W II | 4.8 | −6.4 |