What are the preferred horizontal displacements of aromatic–aromatic interactions in proteins? Comparison with the calculated benzene–benzene potential energy surface

Abstract

The data from protein structures from the Protein Data Bank and quantum chemical calculations indicate the importance of aromatic–aromatic interactions at large horizontal displacements (offsets). The protein stacking interactions of the phenylalanine residue show preference for large offsets (3.5–5.0 Å), while the calculations show substantially strong interactions, of about −2.0 kcal mol⁻¹.