Open AccessCation-π interactions in structural biology
Author(s) -
Justin P. Gallivan,
Dennis A. Dougherty
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.17.9459
Subject(s) - cationic polymerization , protein data bank , chemistry , pi , crystallography , protein structure , stereochemistry , biochemistry , organic chemistry
Cation-π interactions in protein structures are identified and evaluated by using an energy-based criterion for selecting significant sidechain pairs. Cation-π interactions are found to be common among structures in the Protein Data Bank, and it is clearly demonstrated that, when a cationic sidechain (Lys or Arg) is near an aromatic sidechain (Phe, Tyr, or Trp), the geometry is biased toward one that would experience a favorable cation-π interaction. The sidechain of Arg is more likely than that of Lys to be in a cation-π interaction. Among the aromatics, a strong bias toward Trp is clear, such that over one-fourth of all tryptophans in the data bank experience an energetically significant cation-π interaction.