Histidine in Proteins: pH-Dependent Interplay between π-π, Cation-π, and CH-π Interactions.

ABSTRACT: Histidine (His) stands out as the most versatile natural amino acid due to its side chain's facile propensity to protonate at physiological pH, leading to a transition from aromatic to cationic characteristics and thereby enabling diverse biomolecular interactions. In this study, our objective was to quantify the energetics and geometries of pairwise interactions involving His at varying pH levels. Through quantum chemical calculations, we discovered that His exhibits robust participation in both π-π and cation-π interactions, underscoring its ability to adopt a π or cationic nature, akin to other common residues. Of particular note, we found that the affinity of protonated His for aromatic residues (via cation-π interactions) is greater than the affinity of neutral His for either cationic

SUBMITTER: Calinsky R 

PROVIDER: S-EPMC11325542 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature