On the relation between residue flexibility and residue interactions in proteins

Area of Science:

• Structural Biology
• Computational Biology
• Biophysics

Background:

• Protein structural flexibility, quantified by B-factor from X-ray crystallography, is crucial for biological processes like catalysis, binding, and molecular recognition.
• Understanding the determinants of protein flexibility is key to elucidating protein function.

Purpose of the Study:

• To investigate the relationship between residue flexibility and inter-residue interactions within protein structures.
• To develop a predictive model for residue B-factors based on network topological parameters.

Main Methods:

• Representing protein structures as residue contact networks.
• Employing established network topological parameters to characterize inter-residue interactions.
• Constructing a prediction model for B-factor using support vector regression (SVR).

Main Results:

• Significant correlations were found between B-factors and various network topological parameters.
• The SVR model achieved Pearson correlation coefficients (CC) of 0.63 for single amino acids and 0.62 for the entire sequence.
• These findings indicate that inter-amino acid interactions effectively characterize protein structural flexibility.

Conclusions:

• Protein structural flexibility can be accurately characterized by analyzing inter-amino acid interactions within a residue contact network.
• Network topological parameters offer valuable insights into the flexibility of protein structures.
• This approach provides a foundation for further studies on protein function and dynamics.