1em4

Publication Abstract from PubMed

Proteins can use aromatic side-chains to stabilize bound cationic ligands through cation-pi interactions. Here, we report the first example of the reciprocal process, termed pi-cation, in which a cationic protein side-chain stabilizes a neutral aromatic ligand. Site-directed mutagenesis revealed that an arginine side-chain located in the deep binding pocket of a monoclonal antibody (4D5) is essential for binding the neutral polynuclear aromatic hydrocarbon benzo[a]pyrene. This Arg was very likely selected for in the primary response, further underscoring the importance of the pi-cation interaction for ligand binding, which should be considered in protein analysis and design when ligands include aromatic groups.

Stabilization of bound polycyclic aromatic hydrocarbons by a pi-cation interaction.,Pellequer JL, Zhao B, Kao HI, Bell CW, Li K, Li QX, Karu AE, Roberts VA J Mol Biol. 2000 Sep 22;302(3):691-9. PMID:10986127^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.