A CONFORMATIONAL ANALYSIS FOR LEUCINE‐ENKEPHALIN USING ACTIVITY AND BINDING DATA OF SYNTHETIC ANALOGUES

Abstract
1 Leucine-enkephalin and some analogues were assayed for activity in vitro on the mouse vas deferens and for binding to opiate receptors from rat brain. 2 The experimental data were analysed in terms of the stringency for glycine, a D-amino acid or an L-amino acid at each position in the peptide. 3 The observed configurational specificity was compared with the stringency that would be predicted to occur if enkephalin adopted certain hydrogen-bonded conformations at the receptor. 4 A small subset of the conformations examined was found to be compatible with the experimental data.