Characterizing protein conformations by correlation analysis of coarse-grained contact matrices

Area of Science:

• Computational biology
• Biophysics
• Structural biology

Background:

• Residue-residue contact analysis effectively detects conformational changes in biomolecular complexes.
• Analyzing large protein systems (>1000 residues) using residue contacts is computationally challenging.
• Current residue-based methods cannot compare proteins with varying sequences.

Purpose of the Study:

• To develop a scalable and sequence-independent method for analyzing biopolymer conformational dynamics.
• To overcome the limitations of residue-level contact analysis for large and diverse protein systems.

Main Methods:

• Developed a coarse-graining strategy to group consecutive residues into segments.
• Defined segment-segment contacts based on underlying residue-residue contacts.
• Performed covariance calculations on coarse-grained contact matrices.
• Evaluated the preservation of principal components using various rendering functions.

Main Results:

• The coarse-grained method significantly reduces the degrees of freedom for conformational space description.
• The new approach enables the analysis of systems approximately tenfold larger than residue-contact methods.
• This method allows for the comparison of protein structures across different sequences by mapping them to a common conformational space.

Conclusions:

• Coarse-grained segment-segment contact analysis offers a powerful and scalable alternative to residue-level analysis for biopolymer dynamics.
• This method enhances the study of large protein systems and facilitates comparative structural analysis of homologous proteins.