Structural compliance: A new metric for protein flexibility.

Area of Science:

• Structural biology
• Biophysics
• Computational biology

Background:

• Protein dynamics are crucial for molecular functions and are often studied using intrinsic fluctuations.
• Protein motions are influenced by solvent interactions, which traditional methods may not fully capture.

Purpose of the Study:

• Introduce structural compliance as a novel metric for evaluating protein deformability.
• Assess the correlation of structural compliance and stiffness with experimental B-factors.
• Explore the applicability of this approach to other biomolecular structures.

Main Methods:

• Developed a new concept: structural compliance, to assess global and local protein deformability.
• Applied pairwise pulling forces to a protein elastic network model.
• Computed structural compliance and its inverse, structural stiffness.

Main Results:

• Structural compliance shows improved correlation with experimental B-factors compared to mean square fluctuations.
• Structural stiffness exhibits a clear anticorrelation with experimental B-factors.
• The approach is applicable to proteins and potentially other biomolecular structures like RNA.

Conclusions:

• Structural compliance offers a potentially superior metric for protein flexibility, especially for local perturbations.
• The concept of structural compliance and stiffness can be extended to molecular dynamics simulations.
• This work provides a new tool for analyzing protein dynamics and flexibility.