title: The crystal structure of Afc-containing peptides.
abstract: A systematic structural analysis of Afc (9-amino-fluorene-9-carboxylic acid) containing peptides is here reported. The crystal structures of four fully protected tripeptides containing the Afc residue in position 2: Z-X(1)-Afc(2)-Y(3)-OMe (peptide a: X = Y = Gly; peptide b: X = Aib, C(alpha, alpha)-dimethylglycine, Y = Gly; peptide c: X = Gly, Y = Aib; peptide d: X = Y = Aib) have been solved by x-ray crystallography. All the results suggest that the Afc residue has a high propensity to assume an extended conformation. In fact, the Afc residue adopts an extended conformation in three peptides examined in this paper (peptides a-c). In contrast, Afc was found in a folded conformation, in the 3(10)-helical region, only in the peptide d, in which it is both preceded and followed by the strong helix promoting Aib.
authors.affiliation: Centro Interuniversitario di Ricerca su Peptidi Bioattivi, CNR, University of Napoli "Federico II" via Mezzocannone 4, I-80134 Napoli, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Lombardi
authors.forename: G
authors.initials: G
authors.lastname: De Simone
authors.forename: S
authors.initials: S
authors.lastname: Galdiero
authors.forename: F
authors.initials: F
authors.lastname: Nastri
authors.forename: L
authors.initials: L
authors.lastname: Di Costanzo
authors.forename: K
authors.initials: K
authors.lastname: Makihira
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: V
authors.initials: V
authors.lastname: Pavone
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005449:Fluorenes / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: C119175:9-amino-9-fluorenecarboxylic acid; D000596:Amino Acids; D005449:Fluorenes; D009842:Oligopeptides; D005998:Glycine