FIGURE 3.

Simulation of IRRA spectra of a β-sheet secondary structure on H₂O. The calculation has been performed for p-polarized light and an angle of incidence of 40° for the amide I bands at 1625 and 1690 cm⁻¹ and the amide II band at 1535 cm⁻¹. The respective β-sheet is lying flat at the air/water interface (solid line), oriented perpendicular to the interface with the peptide chains parallel to the interface (dashed line), or oriented perpendicular to the interface with the direction of the peptide chains perpendicular to the interface (dotted line).