Exciton dynamics in amide-I [Formula: see text] -helix protein chains with long-range intermolecular interactions

Area of Science:

• Biophysics
• Molecular Biophysics
• Protein Dynamics

Background:

• Proteins utilize amide-I vibrations for energy transport, often modeled as excitons.
• Adenosine triphosphate hydrolysis fuels these vibrations, which can form nonlinear localized excitations (excitons).
• Current models primarily consider short-range interactions between peptide groups.

Purpose of the Study:

• To investigate the impact of long-range interactions on amide-I excitons in protein chains.
• To analyze the effects on modulational instability and soliton wavetrain characteristics.
• To understand how saturating long-range interactions influence energy transport.

Main Methods:

• Theoretical investigation of amide-I molecular chains.
• Analysis of vibration mode dispersion under varying interaction ranges.
• Mathematical modeling of exciton soliton wavetrain parameters.

Main Results:

• Long-range interactions narrow the modulational instability regions for small-amplitude excitons.
• Exciton soliton wavetrain parameters (velocity, tail, width) are significantly enhanced.
• Energy transport via excitons is substantially increased compared to short-range interaction models.

Conclusions:

• Long-range interactions play a crucial role in protein energy transport dynamics.
• The findings suggest a greater capacity for energy transfer along protein chains than previously predicted.
• This research provides new insights into the mechanisms of biological energy propagation.