Global energy minimization of alanine dipeptide via barrier function methods

Area of Science:

• Computational chemistry
• Molecular modeling
• Biophysics

Background:

• Determining the minimum energy conformation of peptides is crucial for understanding their structure-function relationships.
• Existing methods for conformational analysis can be computationally intensive.
• Accurate modeling of van der Waals interactions is essential for reliable energy minimization.

Purpose of the Study:

• To present a novel interior point method utilizing a barrier function algorithm for peptide conformational analysis.
• To determine the minimum energy conformation of alanine dipeptide using internal coordinates.
• To compare the proposed algorithm's performance against a genetic algorithm approach.

Main Methods:

• Minimization of the CHARMM energy function over internal atomic coordinates.
• Implementation of a barrier function algorithm using the Lennard-Jones 6-12 potential.
• Application to alanine dipeptide with varying dihedral angles and to polyalanine structures.

Main Results:

• The barrier function algorithm successfully determined minimum energy conformations for alanine dipeptide.
• Performance was evaluated and compared against results obtained from a genetic algorithm.
• The algorithm was also applied to polyalanine structures, demonstrating its broader applicability.

Conclusions:

• The proposed barrier function algorithm offers an effective approach for peptide conformational energy minimization.
• This method provides a viable alternative to existing computational strategies for molecular modeling.
• The study highlights the potential of interior point methods in computational biophysics.