Minimal folding pathways for coarse-grained biopolymer fragments

Area of Science:

• Biophysics
• Computational Biology
• Structural Biology

Background:

• Understanding biopolymer folding pathways is crucial for protein function.
• Existing methods often use root mean-squared distance (RMSD), which may not fully capture complex conformational changes.

Purpose of the Study:

• To define and apply a generalized distance metric for minimal biopolymer folding pathways.
• To investigate the impact of chain noncrossing on the kinetic proximity of protein conformations.

Main Methods:

• Generalizing Euclidean distance for one-dimensional objects like polymers.
• Calculating minimal folding pathways for protein fragments (helix, beta-hairpin, nonplanar structures).
• Comparing generalized distance with RMSD and mean root-squared distance (MRSD).

Main Results:

• The generalized distance metric effectively identifies minimal folding pathways.
• Chain noncrossing significantly influences the kinetic proximity of protein conformations.
• Aligning structures using MRSD yields different orientations than using RMSD, especially for beta-hairpins.

Conclusions:

• The proposed distance metric offers a more accurate representation of biopolymer folding dynamics.
• Chain noncrossing is a critical factor in determining the kinetic landscape of protein folding.
• MRSD provides a better approximation of true distance for long chains compared to RMSD.