title: Synthesis and NMR conformational analysis of a beta-turn mimic incorporated into gramicidin S. A general approach to evaluate beta-turn peptidomimetics.
abstract: The solution structure of a gramicidin S (GS) analog containing a beta-turn mimic [BTD4-5, Lys2.2']GS has been compared to that of native GS. The linear [BTD4-5, Lys2.2']GS was synthesized by solid phase methodology and the cyclized peptide was analyzed by NMR. In the peptide portion of [BTD4-5, Lys2.2']GS, the intramolecular hydrogen bonding pattern, inter-residue NOEs, including a transannular H alpha-H alpha NOE, and JN alpha coupling constants all describe a solution structure which is equivalent to that of native GS. These data confirm that the BTD group is a competent Type II' beta-turn mimic since it does not disrupt the native conformation of GS. It also supports the use of GS as a conformational model in which to test beta-turn mimics.
authors.affiliation: DuPont Merck Pharmaceutical Company, Wilmington, DE.
authors.forename: A C
authors.initials: AC
authors.lastname: Bach
authors.forename: J A
authors.initials: JA
authors.lastname: Markwalder
authors.forename: W C
authors.initials: WC
authors.lastname: Ripka
mesh_terms: D000595:Amino Acid Sequence; D006096:Gramicidin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data
chemical_list: D006096:Gramicidin