[Ligand recognition in the opioid receptors by modeling methods and the design of opioids].

For understanding the three-dimensional mechanisms that control potency and selectivity of the ligand binding at the atomic level, we have analysed opioid receptor-ligand interaction based on the receptor's 3D model. The analyses of the interactions of some opioid ligands with the predicted ligand binding sites are consistent with the results of the affinity labeling experiments. On the basis of the three-dimensional structures of the putative binding sites in the opioid receptors, a potent kappa agonist KT-95 was designed in our laboratory.