Ligand-receptor interaction under periodic stimulation: a modeling study of concentration chemoreceptors

Area of Science:

• Biophysics
• Chemical Signaling
• Molecular Dynamics

Background:

• Chemosensory transduction begins with ligand-receptor binding on cell membranes.
• Periodic ligand concentration changes mimic natural stimuli, such as in olfaction.
• Understanding ligand-receptor complex dynamics is crucial for chemosensory processes.

Purpose of the Study:

• To analyze the time evolution of ligand-receptor complexes under periodic ligand concentration changes.
• To determine transient and steady-state levels for single-step (binding) and double-step (binding and activation) reactions.
• To compare analytical and numerical solutions and validate models with experimental data.

Main Methods:

• Mathematical modeling of ligand-receptor binding and activation kinetics.
• Derivation of analytical solutions for simplified models (low ligand concentration).
• Numerical simulations for complete and simplified models.
• Comparison with experimental data from moth sex-pheromone receptors.

Main Results:

• Periodic steady states are rapidly achieved.
• The amplitude of complex levels decreases as stimulation frequency increases.
• A simplified model is adequate when a fraction of activated receptors suffices for maximum response.
• An optimal stimulation frequency range of 2–5 Hz was identified.

Conclusions:

• The study provides insights into the dynamics of chemosensory transduction under fluctuating ligand concentrations.
• The simplified model offers a practical approach for analyzing ligand-receptor interactions in specific biological contexts.
• The findings have implications for understanding olfactory signaling and receptor behavior.