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Updated: Mar 5, 2026
07:33
Analyzing Protein Architectures and Protein-Ligand Complexes by Integrative Structural Mass Spectrometry
Published on: October 15, 2018
15.1K
Structural and energetic study of cation-π-cation interactions in proteins
Silvana Pinheiro1, Ignacio Soteras, Josep Lluis Gelpí
1Departament de Farmàcia i Tecnologia Farmacèutica i Fisicoquímica and Institut de Biomedicina (IBUB), Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain. carles.curutchet@ub.edu.
Physical Chemistry Chemical Physics : PCCP
|March 30, 2017
Summary
Cation-π-cation interactions, a novel motif in proteins, occur with aromatic residues like Tryptophan. These interactions are conserved and can be stabilizing, despite initial cation repulsion.
Area of Science:
- Structural biology
- Computational chemistry
- Protein science
Background:
- Cation-π interactions are crucial in protein structure and function.
- The cation-π-cation motif is an understudied interaction in proteins.
Purpose of the Study:
- To statistically analyze the occurrence, composition, and geometry of cation-π-cation interactions in protein structures.
- To investigate the energetic characteristics and functional implications of this motif.
Main Methods:
- Statistical analysis of non-redundant protein structures from the Protein Data Bank.
- Quantum-chemical calculations combined with continuum solvation models for energetic analysis.
Main Results:
- Cation-π-cation motifs are found at a non-negligible frequency, preferring Tryptophan, Tyrosine, and Phenylalanine residues.
- These interactions are highly conserved across protein structures.
- The protein environment screens cation-cation repulsion, resulting in attractive interactions in 64% of analyzed complexes.
Conclusions:
- Cation-π-cation interactions likely play a stabilizing role in protein folding.
- The significant contribution of non-additive terms challenges the use of standard force fields for simulating these motifs.
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