Abstract
Shape complementarity, electrostatic and hydrophobic matching, were used to model drugs and receptors. From known experimental data on α1A/α2A−adrenergic ligands and α1A/α2A−alrenoceptors, a model for the ligand binding sites, based on the structure of bacteriorhodopsin as a template, was proposed and built. Agonists and antagonists have overlapping but different binding sites. Emphasis was given on the role of the disulphide bridge and on the role of the sodium site. The model was extended to other G-protein coupled receptors.