title: The polypeptide 3(10)-helix as a template for molecular recognition studies. Structural characterization of a side-chain functionalized octapeptide.
abstract: A N alpha-blocked, Aib-rich octapeptide methylamide containing two N omega-benzoylated L-Lys residues at positions 3 and 6 was synthesized by solution methods and fully characterized. A solution and crystal-state conformational analysis, performed by using FT-IR, 1H NMR, CD, and X-ray diffraction techniques, showed that the peptide is folded into a regular, right-handed 3(10)-helix stabilized by seven consecutive N-H...O=C intramolecular H-bonds of the beta-turn III type. The two benzamidobutyl L-Lys side chains, located on the same side of the helix after one complete turn, generate a cleft the minimal width of which was found to be 3.47 A.
authors.affiliation: Department of Organic Chemistry, University of Padova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Toniolo
authors.forename: A
authors.initials: A
authors.lastname: Bianco
authors.forename: F
authors.initials: F
authors.lastname: Formaggio
authors.forename: M
authors.initials: M
authors.lastname: Crisma
authors.forename: G M
authors.initials: GM
authors.lastname: Bonora
authors.forename: E
authors.initials: E
authors.lastname: Benedetti
authors.forename: V
authors.initials: V
authors.lastname: Del Duca
authors.forename: M
authors.initials: M
authors.lastname: Saviano
authors.forename: B
authors.initials: B
authors.lastname: Di Blasio
authors.forename: C
authors.initials: C
authors.lastname: Pedone
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013698:Templates, Genetic; D014961:X-Ray Diffraction
chemical_list: D009842:Oligopeptides