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Agonists and Antagonists Show Different Unbinding Paths from the TLR8 Receptor
Valerij Talagayev1, Gerhard Wolber1, Ariane Nunes-Alves2
1Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany.
Journal of Chemical Information and Modeling
|July 9, 2025
Summary
Toll-like receptor 8 (TLR8) ligand unbinding pathways were revealed using τ-random acceleration molecular dynamics (τRAMD) simulations. Ligand type influences pathway preference, aiding the development of novel immunomodulators for autoimmune diseases.
Area of Science:
- Immunology
- Computational Biology
- Structural Biology
Background:
- Toll-like receptors (TLRs) are crucial innate immune sensors.
- TLR8 activation influences autoimmune disease pathogenesis and hyperinflammation.
- Understanding ligand-receptor interactions is key for therapeutic development.
Purpose of the Study:
- To elucidate the unbinding mechanisms of TLR8 agonists and antagonists.
- To identify distinct ligand unbinding pathways from TLR8.
- To provide insights for designing targeted TLR8 modulators.
Main Methods:
- Utilized τ-random acceleration molecular dynamics (τRAMD) simulations.
- Analyzed unbinding pathways of one TLR8 agonist and five TLR8 antagonists.
- Investigated ligand interactions with the Toll-interleukin-1 receptor (TIR) domain.
Main Results:
- Discovered two primary unbinding pathways: internal (towards TIR domain) and external (away from TIR domain).
- TLR8 agonist exclusively used the external pathway.
- Cationic antagonists exclusively used the internal pathway, while neutral antagonists used both.
Conclusions:
- Ligand properties dictate TLR8 unbinding pathways.
- Mechanistic understanding can guide the design of selective TLR8 modulators.
- This study offers novel insights into TLR8-ligand dynamics for therapeutic applications.
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