Configurational Entropy Components and Their Contribution to Biomolecular Complex Formation

Area of Science:

• Biophysics
• Computational Chemistry
• Molecular Dynamics

Background:

• Configurational entropy change is crucial for biomolecular binding free energy.
• Experimental and computational challenges limit understanding of individual entropy contributions.

Purpose of the Study:

• Develop a novel analytical framework to dissect configurational entropy change.
• Quantify contributions from internal and external molecular degrees of freedom.
• Analyze coupled and uncoupled contributions without external fields.

Main Methods:

• Developed a fully analytical framework for entropy dissection.
• Utilized a parallel implementation of the maximum information spanning tree algorithm.
• Performed extensive molecular dynamics simulations of protein binding.

Main Results:

• Demonstrated significant contributions from various coupling terms to configurational entropy change.
• Showed that coupling terms are more important than previously assumed.
• Found that total configurational entropy change can be approximated by internal degrees of freedom.

Conclusions:

• The developed framework provides a detailed understanding of configurational entropy contributions.
• Challenges existing assumptions regarding the dominant factors in entropy change.
• Supports the validity of Nuclear Magnetic Resonance (NMR)-based methods for entropy estimation.