Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The third and fifth aromatic residues of dermorphin, a potent μ-opioid peptide, and of its N-terminal fragments, from the pentapeptide to the parent heptapeptide amide, have been systematically substituted with Z-dehydrophenylalanine (Δ-Phe) and/or Phe to investigate the conformation-activity relationship.The characterization in DMSO-d6 at 500 MHz indicates that, in this solvent, all peptides adopt essentially random, extended conformations, as a consequence of the strong solvation. The chemical shift of the methyl group of D-Ala is influenced by the precise orientation of the side chain of the third residue in a fashion that can be correlated to the μ potency, consistently with our model of μ-receptor.However, the complexes of the pentapeptides with 18-crown-6-ether, when dissolved in chloroform, adopt ordered, folded conformations, a behavior that closely parallels the CD observations in methanol.
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