The unfolding effects on the protein hydration shell and partial molar volume: a computational study

Area of Science:

• Biophysics
• Computational Chemistry
• Protein Science

Background:

• Understanding protein solvation is crucial for comprehending protein behavior in aqueous environments.
• Characterizing the hydration shell and partial molar volumes of proteins in native and unfolded states provides fundamental insights into protein structure-function relationships.

Purpose of the Study:

• To computationally analyze the solvation properties of native and unfolded proteins.
• To quantitatively evaluate protein unfolded state hydration shells and partial molar volumes.
• To determine the variations in partial molar volumes upon protein unfolding (unfolding partial molar volumes) and their temperature/pressure dependence.

Main Methods:

• Application of a recently proposed computational analysis method.
• Characterization of solvation properties in native and four model unfolded protein aqueous solutions.
• Quantitative evaluation of partial molar volumes and hydration shells.
• Reconstruction of temperature and pressure dependence for unfolding partial molar volume.

Main Results:

• Detailed characterization of the protein unfolded state hydration shell.
• Quantitative evaluation of protein unfolded state partial molar volumes.
• Obtained unfolding partial molar volumes for comparison with experimental data.
• Dissected structural and hydration effects on the temperature and pressure dependence of Myoglobin's unfolding partial molar volume.

Conclusions:

• The computational approach effectively characterizes protein solvation, hydration shells, and partial molar volumes in both native and unfolded states.
• The study provides quantitative data on unfolding partial molar volumes, aiding in the comparison with experimental findings.
• Insights into the structural and hydration contributions to the volume changes during protein unfolding were obtained, particularly for Myoglobin.