Local heterogeneous dynamics of water around lysozyme: a computer simulation study

Area of Science:

• Biophysics
• Structural Biology
• Computational Chemistry

Background:

• Water near protein surfaces exhibits distinct dynamics compared to bulk water.
• Understanding protein-water interactions is crucial for comprehending protein function and stability.

Purpose of the Study:

• To investigate the relationship between the mobility of water molecules in protein hydration layers and the local rigidity of protein segments.
• To explore the microscopic dynamics of hydrogen bonds between water and protein residues.

Main Methods:

• Atomistic molecular dynamics simulations of hen egg-white lysozyme in aqueous solution.
• Calculation of hydrogen bond kinetics (breaking and reformation).
• Analysis of low-frequency vibrational modes of hydration layer water molecules.

Main Results:

• Heterogeneous water mobility around protein segments correlates with hydration layer rigidity.
• Broken hydrogen bonds reform more frequently in hydration layers of rigid protein segments.
• Protein influences transverse and longitudinal water degrees of freedom differentially.

Conclusions:

• Protein segment rigidity directly impacts the dynamics of water molecules in its hydration shell.
• The findings provide insights into the complex interplay between protein structure and water dynamics.
• Experimental validation of these simulation-based findings is encouraged.