title: [Synthesis and biological activity of a lysine-containing cyclic analog of [Leu5]enkephalin].
abstract: The cyclic analogue of [Leu5]enkephalin--cyclo (Lys-Tyr-Gly-Gly-Phe-Leu) and two corresponding linear hexapeptides with lysine residue attached to the N- or C-terminus of the molecule have been synthesized by classical methods of peptide chemistry. The addition of lysine residue to the N-terminus of cyclization of the molecule reduce the interaction of these analogues with both central and peripheral opiate receptors. The addition of lysine residue to the C-terminus of the molecule through the epsilon-amino group does not affect the interaction of the analogue with mu-receptors but reduces approximately tenfold its affinity for delta-receptors. All three analogues have analgesic potency similar to that of [Leu5]enkephalin as assayed after intracisternal administration to mice.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism; D012671:Seminiferous Tubules / Q000187:drug effects
chemical_list: D010456:Peptides, Cyclic; D011957:Receptors, Opioid; D004743:Enkephalin, Leucine; C047199:cyclo(lysyl-tyrosyl-glycyl-glycyl-phenylalanyl-leucyl)
vernacular_title: Sintez i biologicheskaia aktivnost' lizinsoderzhashchego tsikloanaloga [Leu5]énkefalina.