title: Conformational features responsible for binding of cyclic analogues of enkephalin to opioid receptors. I. Low-energy peptide backbone conformers of analogues containing Phe4.
abstract: Low-energy peptide backbone conformers were found by means of energy calculation for several cyclic analogues of enkephalin in an attempt to assess models for receptor-bound conformations for opioid receptors of the mu- and delta-types. They included [D-Cys2, L-Cys5]- and [D-Cys2, D-Cys5]-enkephalinamides showing moderate preference for mu-receptors, the delta-selective compounds [D-Pen2, L-Pen5] and [D-Pen2, D-Pen5]-enkephalins and Tyr-D-Lys-Gly-Phe- analogue possessing very high affinity to receptors of the mu-type. The low-energy conformers obtained for these analogues were in good agreement with the results of calculations by other authors and with experimental evidence. All of the analogues contain a Phe residue in position 4 of the peptide chain which facilitates the eventual search for geometrical similarity between the low-energy backbone conformers of different analogues in question.
authors.affiliation: Institute of Organic Synthesis, Latvian SSR Academy of Sciences, Riga.
authors.forename: G V
authors.initials: GV
authors.lastname: Nikiforovich
authors.forename: J
authors.initials: J
authors.lastname: Balodis
authors.forename: M D
authors.initials: MD
authors.lastname: Shenderovich
authors.forename: A A
authors.initials: AA
authors.lastname: Golbraikh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004745:Enkephalins / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010649:Phenylalanine; D011487:Protein Conformation; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D004745:Enkephalins; D011957:Receptors, Opioid; D010649:Phenylalanine