Universal features of fluctuations in globular proteins

Area of Science:

• Structural biology
• Biophysics
• Statistical mechanics

Background:

• Protein B-factors quantify atomic motion and flexibility.
• Understanding B-factor distributions is crucial for interpreting protein dynamics.

Purpose of the Study:

• To identify universal patterns in protein residue B-factor distributions.
• To establish a predictive model for B-factor distributions based on fundamental principles.

Main Methods:

• Analysis of 2000 non-homologous protein crystal structures.
• Application of maximum entropy arguments.
• Derivation of a master curve and linear transformation for specific proteins.

Main Results:

• Protein B-factor distributions collapse onto a single master curve.
• The master curve is identified as a Gamma function.
• Perturbations to B-factor distributions decrease protein entropy.

Conclusions:

• A universal statistical behavior exists for protein residue B-factors.
• The Gamma function provides a robust model for B-factor distributions.
• B-factor distribution analysis offers insights into protein stability and entropy.