title: Heterogeneous exchange behavior of Samia cynthia ricini silk fibroin during helix-coil transition studied with (13)C NMR.
abstract: The structure and structural transition of the glycine residue adjacent to the N-terminal alanine residue of the poly(L-alanine), (Ala)(12-13), region in Samia cynthia ricini silk fibroin was studied using (13)C nuclear magnetic resonance (NMR). Most of the glycine carbonyl peaks in the (13)C solution NMR spectrum of [1-(13)C]glycine-silk fibroin could be assigned to the primary structure from the comparison of the (13)C chemical shifts of seven glycine-containing tripeptides. The slow exchange between helix and coil forms in the NMR time scale was observed with increasing temperature exclusively for the underlined glycine residue in the Gly-Gly-(Ala)(12-13) sequence during fast helix-coil transition of the (Ala)(12-13) region.
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
authors.forename: Yasumoto
authors.initials: Y
authors.lastname: Nakazawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Asakura
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D005349:Fibroins / Q000378:metabolism*; D009036:Moths / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D013696:Temperature
chemical_list: D002247:Carbon Isotopes; D005349:Fibroins