title: Promotion of sheet formation in alpha-peptide strands by a beta-peptide reverse turn.
abstract: [structure: see text]We show that a tetrapeptide with a heterogeneous backbone, i.e., with two different classes of amino acid residues, adopts a hairpin conformation in which each type of residue plays a different structural role. The alpha-residues at the ends form hydrogen bonds characteristic of antiparallel beta-sheet secondary structure, while the central di-beta-peptide segment forms a reverse turn. The configuration of the turn residues is critical to sheet formation.
authors.affiliation: Department of Chemistry and Graduate Program in Biophysics, University of Wisconsin, Madison 53706, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Huck
authors.forename: J D
authors.initials: JD
authors.lastname: Fisk
authors.forename: S H
authors.initials: SH
authors.lastname: Gellman
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D009557:Nipecotic Acids / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives*; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D009557:Nipecotic Acids; D010455:Peptides; C030278:nipecotic acid; D011392:Proline; C010983:homoproline