Empirical solvent-mediated potentials hold for both intra-molecular and inter-molecular inter-residue interactions

Area of Science:

• Biochemistry
• Structural Biology
• Computational Biology

Background:

• Knowledge-based potentials are crucial for understanding protein structure and interactions.
• The applicability of intra-molecular potentials to inter-molecular protein-protein interfaces is debated.
• Differences in chain connectivity and residue packing may affect energetics.

Purpose of the Study:

• To derive and compare inter-molecular inter-residue potentials from protein-protein interfaces with intra-molecular potentials.
• To investigate the role of solvent mediation versus average residue mediation in these interactions.
• To develop a reduced set of energy parameters for protein interactions.

Main Methods:

• Statistical methods were used to extract inter-molecular potentials from protein-protein interfaces.
• Two sets of energy parameters were derived: solvent-mediated and average residue-mediated.
• Correlation analysis was performed between intra- and inter-molecular potentials.

Main Results:

• Solvent-mediated inter-molecular potentials highly correlated (0.89) with intra-molecular potentials.
• Average residue-mediated potentials showed weaker correlation (0.69) with intra-molecular potentials.
• A reduced set of 20 one-body and 3 two-body terms accurately reproduced (0.99 correlation) conventional potentials.

Conclusions:

• Solvent mediation plays a significant role in effective inter-residue interactions, both within monomers and at interfaces.
• Intra-molecular potentials, particularly solvent-mediated ones, are valid for inter-molecular protein-protein interactions.
• A simplified energy parameter set can effectively represent protein interactions.