Fig. (4).
A simulation cell containing a model of the CB2 receptor [211] immersed in a fully hydrated palmitoyl-oleoyl-phosphatidylcholine (POPC) lipid bilayer is illustrated here from a microsecond timescale NAMD2 MD simulation [209], The spheres represent the phosphorous atoms of the POPC head-groups. Water and the fatty acid acyl chains of the bilayer have been turned off for simplicity. 2-AG is contoured at its Van der Waals’ radius. In this figure, a 2-AG molecule has entered the CB2 receptor by passing between TMH6 and TMH7. Inset. Subsequent to entry, 2-AG establishes a long lasting interaction with D(275) in the EC-3 loop, a hydrogen bond with S6.58(268), and maintains an intramolecular hydrogen bond.