Probing structural and dynamical transitions in polymer globules by force

Area of Science:

• Biophysics
• Polymer Physics
• Computational Biology

Background:

• Protein and biopolymer dynamics are critical for biological function.
• Understanding these dynamics requires robust model systems and simulation techniques.

Purpose of the Study:

• To investigate the dynamical transitions of polymer globules as a model for proteins.
• To explore the influence of temperature and external forces on polymer globule dynamics.
• To identify mechanisms for controlling conformational changes in biopolymers.

Main Methods:

• Utilized Brownian dynamics simulations.
• Modeled proteins as polymer globules.
• Analyzed size-dependent dynamical transitions under varying temperatures and applied forces.

Main Results:

• Observed a size-dependent dynamical transition from a liquid-like to a frozen state with decreasing temperature.
• Demonstrated that relaxation time diverges at the transition point.
• Showed that external forces can induce and control a stretch-induced melting transition by altering globule size.

Conclusions:

• Polymer globules exhibit distinct liquid-like and frozen states governed by temperature.
• External forces provide a controllable pathway to manipulate biopolymer conformation via globule size.
• This approach offers a general strategy to accelerate conformational changes in natural biopolymers.