title: Turn and helical peptide handedness governed exclusively by side-chain chiral centers.
abstract: We have examined the preferred 3D structure of homopeptides based on an alpha-amino acid lacking the asymmetry at the alpha-carbon but exhibiting chirality in the side chains (at the two beta-carbons). These joint stereochemical properties are remarkably unusual for an alpha-amino acid. To this end, we carried out an experimental investigation by X-ray diffraction and NMR spectrometry. The results point to a well-defined relationship between screw sense of the turn and helix structures formed and side-chain configurations.
authors.affiliation: Department of Organic Chemistry, ICMA, University of Zaragoza-CSIC, 50009 Zaragoza, Spain.
authors.forename: Soledad
authors.initials: S
authors.lastname: Royo
authors.forename: Wim M
authors.initials: WM
authors.lastname: De Borggraeve
authors.forename: Cristina
authors.initials: C
authors.lastname: Peggion
authors.forename: Fernando
authors.initials: F
authors.lastname: Formaggio
authors.forename: Marco
authors.initials: M
authors.lastname: Crisma
authors.forename: Ana I
authors.initials: AI
authors.lastname: Jiménez
authors.forename: Carlos
authors.initials: C
authors.lastname: Cativiela
authors.forename: Claudio
authors.initials: C
authors.lastname: Toniolo
mesh_terms: D003521:Cyclopropanes / Q000737:chemistry*; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013237:Stereoisomerism; D014961:X-Ray Diffraction
chemical_list: C481928:(2S,3S)-1-amino-2,3-diphenylcyclopropanecarboxylic acid; D003521:Cyclopropanes; D010455:Peptides