title: Conformational behaviour of C(alpha,alpha)-diphenylglycine: folded vs. extended structures in DphiG-containing tripeptides.
abstract: The crystal structures of three fully protected tripeptides containing the Dphi g residue (C[alpha,alpha]-diphenylglycine) in the central position are reported, namely Z-Gly-Dphi g-Gly-OMe (a), Z-Gly-Dphi g-Aib-OMe (b) and Z-Aib-Dphi g-Aib-OMe (c). The molecular conformations are quite unusual because the Dphi g residue adopts a folded conformation in the 3(10)-helical region when the following residue adopts a folded conformation of opposite handedness (peptides b and c). In contrast, the Dphi g residue adopts the more frequently observed fully extended conformation when the following residue adopts a semi-extended conformation (peptide a). These findings are in agreement with the theoretical calculations on Ac-Dphi g-Aib-NHCH3 and Ac-Aib-Dphi g-NHCH3 also reported in this work.
authors.affiliation: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi, CEINGE-Biotecnologie Avanzate, Università di Napoli Federico II, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Pavone
authors.forename: A
authors.initials: A
authors.lastname: Lombardi
authors.forename: M
authors.initials: M
authors.lastname: Saviano
authors.forename: F
authors.initials: F
authors.lastname: Nastri
authors.forename: L
authors.initials: L
authors.lastname: Zaccaro
authors.forename: O
authors.initials: O
authors.lastname: Maglio
authors.forename: C
authors.initials: C
authors.lastname: Pedone
authors.forename: Y
authors.initials: Y
authors.lastname: Omote
authors.forename: Y
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: T
authors.initials: T
authors.lastname: Yamada
mesh_terms: D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding; D014961:X-Ray Diffraction
chemical_list: D005998:Glycine