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Cation-pi interactions in protein-protein interfaces.

Peter B Crowley·Adel Golovin
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Abstract

Arginine is an abundant residue in protein-protein interfaces. The importance of this residue relates to the versatility of its side chain in intermolecular interactions. Different classes of protein-protein interfaces were surveyed for cation-pi interactions. Approximately half of the protein complexes and one-third of the homodimers analyzed were found to contain at least one intermolecular cation-pi pair. Interactions between arginine and tyrosine were found to be the most abundant. The electrostatic interaction energy was calculated to be approximately 3 kcal/mol, on average. A distance-based search of guanidinium:aromatic interactions was also performed using the Macromolecular Structure Database (MSD). This search revealed that half of the guanidinium:aromatic pairs pack in a coplanar manner. Furthermore, it was found that the cationic group of the cation-pi pair is frequently involved in intermolecular hydrogen bonds. In this manner the arginine side chain can participate in multiple interactions, providing a mechanism for inter-protein specificity. Thus, the cation-pi interaction is established as an important contributor to protein-protein interfaces.

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Amino AcidsBinding SitesCationsDatabases, ProteinDimerizationHydrogen BondingLigandsProteinsSurface PropertiesThermodynamicsJournal ArticleResearch Support, Non-U.S. Gov't

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Peter B Crowley, Adel Golovin. 2005-05-01. Cation-pi interactions in protein-protein interfaces.. https://doi.org/10.1002/prot.20417

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