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[D-Leu2]deltorphin, a 17 amino acid opioid peptide from the skin of the Brazilian hylid frog, Phyllo

[D-Leu2]deltorphin, a 17 amino acid opioid peptide from the skin of the Brazilian hylid frog, Phyllo

  1. Anonymous
    Peptides. 1994;15(2):199-202.
    Barra D, Mignogna G, Simmaco M, Pucci P, Severini C, Falconieri-Erspamer G, Negri L, Erspamer V

    Abstract

    A novel 17 amino acid peptide, having a D-leucine in position 2 of its sequence, has been isolated from methanol extracts of the skin of the Brazilian frog, Phyllomedusa burmeisteri. The sequence of the peptide is: Tyr-D-Leu-Phe-Ala-Asp-Val-Ser-Thr-Ile-Gly-Asp-Phe-Phe-His-Ser-Ile-NH2. It displays a poor affinity for delta-opioid binding sites, both in the periphery and in the central nervous system. However, the shorter synthetic amidated analogue (1-10) possess both on the central and peripheral delta binding sites an agonistic potency equalling in affinity and exceeding in selectivity that of the enkephalins. The shorter amidated analogue (1-7) is virtually inactive on opioid binding sites in the periphery, but displays a clear-cut affinity for both delta and mu binding sites on rat brain membranes. To date six different D-amino acid residues have been found, always in position 2 of the sequence, in as many as 11 natural peptide molecules of animal origin.