Figure 4.

Schematic (right panel) showing the final deduced orientation of ovispirin (tilt angle = 138°, twist angle = 184°) at the polystyrene/water interface. Left panel defines the reference orientation (tilt angle = 0°, twist angle = 0°) where the hydrophilic region (blue) extends from −60 to +120 degrees around the helix axis. θ₁ is the angle between the transition dipole of ¹³C=O chemical group (purple arrow) and the z axis and θ₂ is the angle between the peptide helix axis (from N to C terminus) (red arrow) and the z axis. For the reference orientation, θ₁=138° and θ₂=0° and for the final deduced orientation, θ₁=23° and θ₂=138°