A computer simulation study of water drying at the interface of protein chains

Area of Science:

• Biophysics
• Computational Chemistry
• Protein Dynamics

Background:

• Hydrophobic interactions are crucial for protein structure and function.
• Understanding water behavior at protein interfaces is key to molecular assembly.
• Protein dimerization involves complex interfacial phenomena.

Purpose of the Study:

• To investigate water drying (cavitation) at the interface of dimeric protein chains.
• To quantify the separation length scale for drying transitions and water expulsion.
• To elucidate the role of hydrophobic interactions in protein chain assembly.

Main Methods:

• Nanosecond molecular dynamics simulations with explicit water.
• Direct observation of separation-induced water cavity formation.
• Analysis of water molecule expulsion and hydrogen bonding changes.

Main Results:

• Direct observation of water cavitation in the interfacial region.
• Quantification of the critical separation length for drying.
• Exponential reduction in interfacial water hydrogen bonds during drying.
• Observed values align with the Kelvin equation for confined systems.

Conclusions:

• Hydrophobic interactions drive protein chain assembly through interfacial water cavitation.
• The study provides insights into the molecular mechanisms of protein dimerization.
• Findings contribute to understanding water's role in biological self-assembly.