Lane et al. proposed that different types of antagonists could prefer specific types of inactive conformations of the dopamine D2 and D3 receptors. Based on the structures of these two receptors, the conformations of D2 bound with the drugs risperidone and eticlopride (two dopamine antagonists) were simulated and compared. The results show that the inactive conformations of D2 were very different when it was bound to eticlopride as opposed to risperidone. In addition D2 and D3 showed a very similar conformation when attached to eticlopride. The two drugs also bound to the inactive receptors in overlapping but different locations. These computational findings, together with experimental validations, suggest that D2 and D3 exist in several inactive states that only allow the binding of specific drugs; these states could also reflect different degrees of inactivation. Overall, the work by Lane et al. contributes to a more refined understanding of the complex conformations of GPCRs, which could be helpful to screen and develop better drugs.
In: Elife, vol. 9, 2020, ISSN: 2050-084X (Electronic); 2050-084X (Linking).