Abstract
The recognition of Cannabis as a source of new compounds suitable
for medical use has attracted strong interest from the scientific
community in its research, and substantial progress has accumulated
regarding cannabinoids’ activity; however, a thorough description of
their molecular mechanisms of action remains a task to complete.
Highlighting their complex pharmacology, the list of cannabinoids’
interactors has vastly expanded beyond the canonical cannabinoid
receptors. Among those, we have focused our study on the glycine
receptor (GlyR), an ion channel involved in the modulation of nervous
system responses, including, to our interest, sensitivity to peripheral
pain. Here, we report the use of computational methods to investigate
possible binding modes between the GlyR and Δ
9-tetrahydrocannabinol (THC). After obtaining a first
pose for the THC binding from a biased molecular docking simulation and
subsequently evaluating it by molecular dynamic simulations, we found a
dynamic system with an identifiable representative binding mode
characterized by the specific interaction with two transmembrane
residues (Phe293 and Ser296). Complementarily, we assessed the role of
membrane cholesterol in this interaction and positively established its
relevance for THC binding to GlyR. Lastly, the use of restrained
molecular dynamics simulations allowed us to refine the description of
the binding mode and of the cholesterol effect. Altogether, our findings
contribute to the current knowledge about the GlyR-THC mode of binding
and propose a new starting point for future research on how cannabinoids
in general, and THC in particular, modulate pain perception in view of
its possible clinical applications.