Chain stiffness bridges conventional polymer and bio-molecular phases

Area of Science:

• Polymer Physics
• Computational Chemistry
• Biophysics

Background:

• Chain molecules are fundamental in both industrial applications and biological systems.
• Modeling molecular stiffness is key to understanding chain behavior.
• Existing models often simplify the complex nature of chain stiffness.

Purpose of the Study:

• To investigate distinct methods for modeling chain molecule stiffness.
• To explore the impact of energetic and entropic stiffness on chain conformations.
• To bridge conventional polymer and biomolecular phase understanding.

Main Methods:

• Utilized detailed Wang-Landau microcanonical Monte Carlo simulations.
• Analyzed three types of stiffness: energetic (bend penalty) and two entropic (conformation restriction).
• Derived an analytical mapping between persistence lengths from different stiffness types.

Main Results:

• Identified a wide spectrum of ground state conformations, including coils, globules, toroids, rods, helices, zig-zags (β-sheets), and knots.
• Demonstrated that different stiffness types have unique physical roles and conformational effects.
• Showed that identical persistence lengths can arise from fundamentally different stiffness mechanisms.

Conclusions:

• The physical origin of stiffness significantly dictates the ground state conformation of chain molecules.
• Distinct stiffness models are necessary to accurately represent diverse chain behaviors.
• This work provides a deeper understanding of polymer and biomolecular conformational landscapes.