title: [Conformation of D-Orn2-containing cycloanalogs of enkephalins in dimethylsulfoxide solution].
abstract: The sterically acceptable structures of cyclo(2 delta----5)[D-Orn2, Pro5]- and cyclo(2 delta----5)[D-Orn2, Leu5]enkephalin (CE1 and CE2) consistent with NMR data including coupling constants, temperature dependencies of chemical shifts for amide protons and NOE values have been found by use of energy calculations in terms of rigid valence geometry and refined by the MM2 procedure. It has been shown that the major trans-isomer (with respect to Phe4-Pro5 bond) of CE1 in solution corresponds only to the FD*F*AA type of peptide backbone, and the minor cis-isomer of CE1 corresponds only to the FE*D*DF type. The less conformationally rigid CE2 analogue apparently exists in solution in the dynamic conformational equilibrium with preference of FD*C*AA type of the backbone structure. The obtained data on CE1 and CE2 space structures have been used for interpretating results of their biological testing.
authors.forename: M D
authors.initials: MD
authors.lastname: Shenderevich
authors.forename: Iu B
authors.initials: IuB
authors.lastname: Saulitis
authors.forename: I V
authors.initials: IV
authors.lastname: Bobrova
authors.forename: A V
authors.initials: AV
authors.lastname: Puchina
authors.forename: N A
authors.initials: NA
authors.lastname: Abissova
authors.forename: G V
authors.initials: GV
authors.lastname: Nikiforovich
authors.forename: G I
authors.initials: GI
authors.lastname: Chipens
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D004745:Enkephalins / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000494:pharmacology; D011487:Protein Conformation; D012671:Seminiferous Tubules / Q000187:drug effects
chemical_list: D004745:Enkephalins; D010456:Peptides, Cyclic; D004743:Enkephalin, Leucine
vernacular_title: Prostranstvennaia struktura D-Orn2-soderzhashchikh tsikloanalogov énkefalina v rastvore dimetilsul'foksida.