Fig. 5.

Modulatory sites at glycine receptors. The most relevant amino acids (highlighted in colored spheres) are shown in a single α3 subunit (right) and for a homopentameric α3 glycine receptor (left). The structural data (PDB ID:5TIO) were taken from [53]. For the compound AM-3607, which binds to an interface of two adjacent subunits, only the residues of the (+) subunit are shown [53]. The residues relevant for the actions of tropeines on glycine receptors have not yet been identified for α3 glycine receptors. The sites indicated are the homologous sites identified originally for the α1 glycine receptor subunit [143–146]. The sites for THC, CBD, propofol and 2,6-DTBP were identified and characterized in [29, 50, 148, 168]. Glycine molecules bound to the orthosteric sites are shown in green