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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1992-8-4
pubmed:abstractText
The conformationally restricted, cyclic disulfide-containing delta opioid receptor selective enkephalin analogue [D-Pen2,D-Pen5] enkephalin (DPDPE) was modified by 2' (CH3) and 3' (I, OCH3, NO2, NH2) ring substitutions and by beta-methyl conformationally constrained beta-methyltyrosine derivatives in the 1 position. The potency and selectivity of these analogues were evaluated by bioassay in the mouse vas deference (MVD, delta receptor assay) and guinea pig ileum (GPI, mu receptor assay) assays and by radioreceptor binding assays in the rat brain using [3H]CTOP (mu ligand) and [3H][p-ClPhe4]DPDPE (delta ligand). The analogues showed highly variable potencies in the binding assays and in the bioassays. Aromatic ring substituents with positive Hammett constants had decreased potency, while substituents with negative Hammett constraints has increased potency for the opioid receptor. The most potent and most selective compound based on the binding was [2'-MeTyr1]DPDPE (IC50 = 0.89 nM and selectivity ratio 1310 in the binding assays). The 6-hydroxy-2-aminotetralin-2-carboxylic acid-containing analogue, [Hat1]DPDPE, also was highly potent and selective in both assays, demonstrating that significant modifications of tyrosine in enkephalins are possible with maintenance of high potency and delta opioid receptor selectivity. Of the beta-methyl-substituted Tyr1 analogues, [(2S,3R)-beta-MeTyr1]DPDPE was the most potent and the delta receptor selective. The results with substitution of beta-MeTyr or Hat instead of Tyr also demonstrate that topographical modification in a conformationally restricted ligand can significantly modulate both potency and receptor selectivity of peptide ligands that have multiple sites of biological activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2384-91
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Ring substituted and other conformationally constrained tyrosine analogues of [D-Pen2,D-Pen5]enkephalin with delta opioid receptor selectivity.
pubmed:affiliation
Department of Chemistry, University of Arizona, Tucson 85721.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't