title: Orientation of spin labels in de novo peptides.
abstract: A series of de novo synthesised peptides including the artificial rigid paramagnetic amino acid TOAC at two positions with different distances from two to seven in the primary structure have been investigated by 9- and 94-GHz EPR spectroscopy under solid-state conditions. From simulations of the spectra of such two-spin systems, the distance and relative orientation of the paramagnetic centres can be deduced. This yields structural information on the peptides. A quantitative analysis of the spectra of individual peptides in different solvents as well as a qualitative analysis of the spectra of the peptide series shows that the peptides do not assume conformations corresponding to any of the common helical structures in proteins.
authors.affiliation: Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Celine
authors.initials: C
authors.lastname: Elsässer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Monien
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Haehnel
authors.forename: Robert
authors.initials: R
authors.lastname: Bittl
mesh_terms: D000595:Amino Acid Sequence; D004578:Electron Spin Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D013113:Spin Labels
chemical_list: D010455:Peptides; D013113:Spin Labels