Aromatic-proline interactions: electronically tunable CH/π interactions.

ABSTRACT: Proline residues have unique roles in protein folding, structure, and function. Proline and the aromatic amino acids comprise the encoded cyclic protein residues. Aromatic protein side chains are defined by their negatively charged π faces, while the faces of the proline ring are partially positively charged. This polarity results from their two-point connection of the side chain to the electron-withdrawing protein backbone, and the lower electronegativity of hydrogen compared to carbon, nitrogen, and oxygen. The hydrogens adjacent to the carbonyl and amide nitrogen, Hα and Hδ, respectively, are the most partially positive. Proline's side chain is also conformationally restricted, allowing for interaction with aromatic residues with minimal entropic or steric penalty. Proline and aromatic

SUBMITTER: Zondlo NJ 

PROVIDER: S-EPMC3780429 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature