title: Solution conformation of the type I collagen alpha-1 chain N-telopeptide studied by 1H NMR spectroscopy.
abstract: The solution conformation of the type I collagen alpha-1 chain N-telopeptide has been studied by CD and 1H NMR spectroscopy at 600 MHz in CD3OH/H2O (60/40 v/v) and H2O solutions. The 19 amino acids form the N-terminal end of the alpha-1 polypeptide chain. By the combined application of several two-dimensional, phase-sensitive NMR techniques (COSY, RELAY, ROESY), a complete assignment of all proton resonances was achieved, and the conformation of the backbone could be established on the basis of the coupling constant and NOE data. In CD3OH/H2O solutions the spectroscopic evidence clearly indicates that two sections of the molecule (pE1-Y6 and T11-M19) are extended and that the D7-S10 segment forms a beta-turn, stabilized by a hydrogen bond between NH(S10) and CO(D7). The data suggest that the turn is of the type I kind (minor) and that it coexists with an extended structure (major conformer). Interactions between the two extended parts of the peptide were not observed, thus excluding the existence of a beta-sheet. In H2O solution the conformation is significantly different, with no beta-turn, but a completely extended structure is observed.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Otter
authors.forename: G
authors.initials: G
authors.lastname: Kotovych
authors.forename: P G
authors.initials: PG
authors.lastname: Scott
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003094:Collagen / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000138:chemical synthesis; D011487:Protein Conformation; D013696:Temperature
chemical_list: D010455:Peptides; D003094:Collagen