Driving Forces in Pressure-Induced Protein Transitions

Area of Science:

• Biochemistry
• Physical Chemistry
• Protein Science

Background:

• Understanding protein denaturation is crucial for various biological and industrial processes.
• Pressure-induced denaturation offers a unique window into protein structural dynamics.

Purpose of the Study:

• To analyze the volumetric changes of amino acids during pressure-induced protein denaturation.
• To identify the key molecular drivers of pressure-induced protein unfolding.

Main Methods:

• Volumetric analysis of peptide groups and amino acid side chains.
• Comparison of native, micelle-like denatured, and unfolded protein states.
• Modeling using low-molecular analogs.

Main Results:

• Increased solvation of peptide groups with pressure is a major driving force.
• Nonpolar side chains show increased hydrophobicity with pressure, forming a dense core.
• Disappearance of large internal voids contributes to denaturation.

Conclusions:

• Solvation of peptide groups and the packing of nonpolar side chains are key to pressure-induced denaturation.
• Pressure-induced denaturation involves significant changes in protein internal volume and voids.
• Findings impact understanding of protein folding kinetics and transition states.