title: A helical peptide receptor for [60]fullerene.
abstract: Two terminally blocked nonapeptides, each made up of six Aib residues, a Gly spacer and two L-Tyr residues in positions 2 and 8 (these are substituted in the side chain with either ferrocenoyl or methyl moieties), have been synthesized by solution methods and fully characterized. FT-IR absorption and two-dimensional NMR analyses indicate that a 3(10)-helical conformation is adopted by these rigid peptides in structure-supporting solvents. An X-ray diffraction investigation shows that the bis-L-Tyr(Me) nonapeptide in the crystal state is folded in a regular right-handed 3(10)-helical structure. As five amino acid units separate the two substituted L-Tyr residues in the peptide sequence, the two side chain moieties will-in solution-face each other after two complete turns of the ternary helix. By carrying out a detailed photophysical analysis, we have demonstrated that the electron-rich, hydrophobic and wide cavity generated by the nonapeptide template with two ferrocenoyloxybenzyl walls is able to host [60]fullerene. Further evidence for this superstructure has been provided in the gas phase by a mass spectrometric investigation.
authors.affiliation: CSB-CNR and CMRO-CNR Dipartimento di Chimica Organica Università di Padova, 35131 Padova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Bianco
authors.forename: Carlo
authors.initials: C
authors.lastname: Corvaja
authors.forename: Marco
authors.initials: M
authors.lastname: Crisma
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Michele
authors.initials: M
authors.lastname: Maggini
authors.forename: Elena
authors.initials: E
authors.lastname: Sartori
authors.forename: Claudio
authors.initials: C
authors.lastname: Toniolo
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D037741:Fullerenes; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D037741:Fullerenes; D010455:Peptides; D002244:Carbon; C069837:fullerene C60