Elucidation of the receptor-bound conformation of the enkephalins.

The biologically relevant conformers of enkephalin predicted by solid state, solution state, and theoretical energy studies have been compared with the published structure-activity data on these compounds. No conformational technique proposes a model consistent with all the pharmacological data; the shortcomings of each approach are evaluated. An alternative approach, which correlates the structure-activity data of opiate compounds with that of the enkephalins, is described and shown to produce a model consistent with the available structure-activity data.