Folding and form: insights from lattice simulations

Area of Science:

• Computational biology
• Protein folding dynamics
• Polymer physics

Background:

• Understanding protein folding mechanisms is crucial for molecular biology and disease research.
• Two-state folders represent a significant class of proteins with simplified folding pathways.
• The Miyazawa-Jernigan model provides a coarse-grained representation of polymer chains.

Purpose of the Study:

• To investigate the distinct folding mechanisms of two-state folders using computational simulations.
• To correlate protein folding pathways with the geometric properties of native structures, specifically contact order.
• To elucidate the role of intermediate states in the folding process.

Main Methods:

• Utilized Monte Carlo simulations to model protein folding.
• Employed the Miyazawa-Jernigan lattice-polymer model for simulations.
• Analyzed folding pathways based on contact order and structural progression.

Main Results:

• Identified two primary classes of folding mechanisms for two-state folders.
• Demonstrated that low contact order folding is driven by backbone distance and involves gradual structure formation.
• Showed that high contact order folding is dominated by transient intermediate contacts, leading to a more cooperative process.

Conclusions:

• Protein folding mechanisms are highly dependent on the native structure's geometry and contact order.
• The folding pathway transitions from progressive structure accumulation to cooperative folding involving intermediates as contact order increases.
• These findings offer insights into the fundamental principles governing protein self-assembly.