Lattice model simulations of polypeptide chain folding

Area of Science:

• Computational biology
• Protein structure prediction
• Biophysics

Background:

• Understanding protein folding is crucial for molecular biology.
• Simulated annealing is a computational method for optimization problems.

Purpose of the Study:

• To investigate the folding process of small monomeric globular proteins using simulated annealing.
• To analyze the transition from a random coil to a compact, low-energy state.

Main Methods:

• Application of simulated annealing to simple cubic lattice C-alpha models.
• Comparison of lowest energy structures with crystal forms using dRMS, RMS, and contact maps.

Main Results:

• Protein collapse initiated by a rapid decrease in radius of gyration.
• Chain repackings involve cooperative local and non-local interactions.
• Shorter segments relax faster, forming local contacts; longer segments relax slower, forming non-local contacts.

Conclusions:

• Simulated annealing effectively models protein folding transitions.
• The final predicted structures largely preserve the native topologies.
• Cooperative interactions drive the formation of compact, low-energy protein structures.