title: Dermorphin gene sequence peptide with high affinity and selectivity for delta-opioid receptors.
abstract: Skin of the frog Phyllomedusa sauvagei contains a cDNA sequence that codes for the selective mu-receptor peptide dermorphin and a new heptapeptide we have designated as dermorphin gene-associated peptide (DGAP). Investigation of the opioid receptor binding characteristics of synthetic DGAP and [D-Met2]DGAP revealed that the latter peptide had high affinity and selectivity for delta-type opioid receptors in rat brain synaptosomes. The IC50 values for DGAP on mu- and delta-receptors were only 28 microM and 670 nM, respectively, while that for [D-Met2]DGAP was 0.80 nM for delta-receptors and greater than 1 microM for mu-receptors yielding a very high delta selectivity ratio (SR) of 1345. In comparison, the SR values for [D-Ala2,D-Leu5]enkephalin, [D-Ser2,Leu5,Thr6]enkephalin, and [D-Pen2,5]enkephalin, ligands which are considered to be specific for delta-receptors, were 20, 42, and 301, respectively. Dermorphin, which contains a D-Ala2 residue and is a selective mu-receptor ligand (Lazarus, L.H., Guglietta, A., Wilson, W.E., Irons, B.J., and de Castiglione, R. (1989) J. Biol. Chem. 264, 354-362), exhibits a SR of 0.0055 similar to that for the conventional mu-agonist [D-Ala2,NMePhe4,Gly-ol]enkephalin (0.0040). This finding that frog skin cDNA contains the information to code for dermorphin and DGAP, or the presumed [D-Met2]DGAP molecule, which are among the most selective high affinity opioid ligands described for mu- and delta-receptors, may permit new insight into the design of future opioid receptor agonists and antagonists.
authors.affiliation: Peptide Neurochemistry Section, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
authors.forename: L H
authors.initials: LH
authors.lastname: Lazarus
authors.forename: W E
authors.initials: WE
authors.lastname: Wilson
authors.forename: R
authors.initials: R
authors.lastname: de Castiglione
authors.forename: A
authors.initials: A
authors.lastname: Guglietta
mesh_terms: D000701:Analgesics, Opioid; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D004745:Enkephalins / Q000378:metabolism; D009842:Oligopeptides / Q000235:genetics* / Q000378:metabolism; D018847:Opioid Peptides; D011487:Protein Conformation; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D013574:Synaptosomes / Q000378:metabolism
chemical_list: D000701:Analgesics, Opioid; D004745:Enkephalins; D009842:Oligopeptides; D018847:Opioid Peptides; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; C030058:dermorphin; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; C034318:enkephalin, Ser(2), Leu(5), Thr(6)-; D020881:Enkephalin, D-Penicillamine (2,5)-