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Updated: Aug 9, 2026
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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Stabilization of bound polycyclic aromatic hydrocarbons by a pi-cation interaction
J L Pellequer1, B Zhao, H I Kao
1Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Journal of Molecular Biology
|September 15, 2000
Summary
Researchers discovered a new protein interaction called pi-cation, where a protein
Area of Science:
- Biochemistry
- Structural Biology
- Protein-Ligand Interactions
Background:
- Proteins utilize cation-pi interactions, involving aromatic side-chains stabilizing cationic ligands.
- The reciprocal interaction, where protein side-chains stabilize neutral aromatic ligands, was previously uncharacterized.
Purpose of the Study:
- To report the first example of the pi-cation interaction.
- To investigate the role of specific protein residues in binding neutral aromatic ligands.
Main Methods:
- Site-directed mutagenesis was employed to alter a specific arginine residue in a monoclonal antibody (4D5).
- The binding affinity of the modified antibody for benzo[a]pyrene was assessed.
Main Results:
- An arginine side-chain in the antibody's binding pocket was found to be essential for binding benzo[a]pyrene.
- This interaction, termed pi-cation, stabilizes the neutral aromatic ligand.
Conclusions:
- The pi-cation interaction is a significant binding mechanism for proteins with neutral aromatic ligands.
- This interaction should be considered in protein analysis and design involving aromatic compounds.
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