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Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
What stabilizes close arginine pairing in proteins?
Dongseon Lee1, Juyong Lee, Chaok Seok
1Department of Chemistry, Seoul National University, Seoul 151-747, Republic of Korea.
Physical Chemistry Chemical Physics : PCCP
|March 15, 2013
Summary
Positively charged arginine pairs in proteins are stabilized by polar networks, not just hydration. This finding reveals a key mechanism for protein structure and function.
Area of Science:
- Biochemistry
- Structural Biology
- Computational Biology
Background:
- Arginine residues, with their positively charged guanidinium groups, often appear in close proximity within protein structures.
- While hydration effects are known to influence arginine interactions, the precise stabilization mechanisms for closely packed arginine pairs in proteins remain unclear.
Purpose of the Study:
- To investigate the stabilization of closely packed, positively charged arginine pairs within protein interiors.
- To elucidate the dominant forces, beyond hydration, that govern the proximity of arginine residues in proteins.
Main Methods:
- Statistical analysis of the protein structure database to determine the frequency of arginine pairs.
- Molecular dynamics simulations and pKa estimation using molecular mechanics-Poisson-Boltzmann calculations for selected arginine pairs.
- Energy decomposition analysis to dissect contributing interaction forces.
Main Results:
- Arginine pairs are found more frequently in protein interiors than predicted by random distribution.
- Buried arginine pairs remain positively charged, and hydration free energy is insufficient to overcome Coulombic repulsion.
- A conserved polar interaction network around buried arginine pairs provides sufficient electrostatic stabilization.
Conclusions:
- Stabilization of buried, like-charged arginine pairs in proteins relies on intricate polar interaction networks, not solely hydration.
- These polar networks play a crucial role in protein stabilization and may be essential for specific biochemical functions.
- The evolutionary conservation of these networks suggests functional importance.
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