Fluorinated Aromatic Amino Acids Distinguish Cation-π Interactions from Membrane Insertion.

ABSTRACT: Cation-π interactions, where protein aromatic residues supply π systems while a positive-charged portion of phospholipid head groups are the cations, have been suggested as important binding modes for peripheral membrane proteins. However, aromatic amino acids can also insert into membranes and hydrophobically interact with lipid tails. Heretofore there has been no facile way to differentiate these two types of interactions. We show that specific incorporation of fluorinated amino acids into proteins can experimentally distinguish cation-π interactions from membrane insertion of the aromatic side chains. Fluorinated aromatic amino acids destabilize the cation-π interactions by altering electrostatics of the aromatic ring, whereas their increased hydrophobicity enhances membrane insertion.

SUBMITTER: He T 

PROVIDER: S-EPMC4521051 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature