Figure 3.

Cycling trajectories for a pentapeptide β-α loop (β-α 3.1.1, PDB code 2TMD, segment 395–399A). ${\varphi }_2$ is constrained at two slightly different values, 104.6° (solid lines) and 106.3° (dashed lines), but this small difference causes radically different trajectories for ${\varphi }_3$,${\psi }_3$ and ${\varphi }_4$,${\psi }_4$(in green and blue, respectively; the ${\varphi }_2$,${\psi }_2$ trajectory is red). The 106.3° trajectory follows the 104.6° trajectory but loops out where the 104.6° trajectory makes a sharp turn.