title: The longest, regular polypeptide 3(10) helix at atomic resolution.
abstract: A synthetic, terminally blocked homodecapeptide from the C alpha, alpha-dimethylated glycyl residue alpha-aminoisobutyric acid has been analyzed by single-crystal X-ray diffraction and the structure refined to R = 0.073. The compound crystallizes as a perfect 3(10) helix, stabilized by eight consecutive intramolecular N-H . . . O = C hydrogen bonds. This is the first observation at atomic resolution of a regular polypeptide 3(10) helix as long as three complete turns.
authors.affiliation: Department of Chemistry, University of Naples, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Pavone
authors.forename: B
authors.initials: B
authors.lastname: Di Blasio
authors.forename: A
authors.initials: A
authors.lastname: Santini
authors.forename: E
authors.initials: E
authors.lastname: Benedetti
authors.forename: C
authors.initials: C
authors.lastname: Pedone
authors.forename: C
authors.initials: C
authors.lastname: Toniolo
authors.forename: M
authors.initials: M
authors.lastname: Crisma
mesh_terms: D000621:Aminoisobutyric Acids; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006860:Hydrogen Bonding; D015394:Molecular Structure; D009842:Oligopeptides; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D000621:Aminoisobutyric Acids; D009842:Oligopeptides; C100049:2-aminoisobutyric acid