A Basis Set for Peptides for the Variational Approach to Conformational Kinetics

Area of Science:

• Computational Chemistry
• Biophysics
• Molecular Dynamics

Background:

• Markov state models (MSMs) are vital for analyzing biomolecular kinetics.
• Discretizing conformational space in MSMs presents a significant challenge.
• A variational approach using basis functions offers systematic control over discretization error.

Purpose of the Study:

• To develop and validate a peptide-specific basis set for variational kinetic modeling.
• To enable systematic control of discretization error in peptide conformational dynamics.
• To provide direct interpretation of slow kinetic modes without additional clustering.

Main Methods:

• Constructed a basis set from local, residue-centered kinetic modes of amino acids.
• Applied the basis set to model conformational kinetics of two hexapeptides (VGLAPG and VGVAPG).
• Utilized variational approach with basis functions instead of discrete states.

Main Results:

• Six basis functions effectively captured the slow kinetic modes of the studied hexapeptides.
• The basis set facilitated direct interpretation of slow kinetic modes.
• Conformational kinetic differences between leucine and valine substitutions were quantifiable.

Conclusions:

• The developed basis set enhances variational kinetic modeling for peptides.
• This approach offers improved accuracy and interpretability in biomolecular kinetics.
• It provides a quantitative method to study sequence-dependent kinetic variations.