title: A study of conformational stability of poly(L-alanine), poly(L-valine), and poly(L-alanine)/poly(L-valine) blends in the solid state by (13)C cross-polarization/magic angle spinning NMR.
abstract: 13C cross-polarization/magic angle spinning (CP/MAS) NMR and (1)H T(1rho) experiments of poly(L-alanine) (PLA), poly(L-valine) (PLV), and PLA/PLV blends have been carried out in order to elucidate the conformational stability of the polypeptides in the solid state. These were prepared by adding a trifluoroacetic acid (TFA) solution of the polymer with a 2.0 wt/wt % of sulfuric acid (H(2)SO(4)) to alkaline water. From these experimental results, it is clarified that the conformations of PLA and PLV in their blends are strongly influenced by intermolecular hydrogen-bonding interactions that cause their miscibility at the molecular level.
authors.affiliation: Department of Chemistry and Materials Science, International Research Center of Macromolecular Science, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Murata
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kuroki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kimura
authors.forename: Isao
authors.initials: I
authors.lastname: Ando
mesh_terms: D001704:Biopolymers / Q000737:chemistry; D002247:Carbon Isotopes; D004355:Drug Stability; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014316:Tritium
chemical_list: D001704:Biopolymers; D002247:Carbon Isotopes; D010455:Peptides; D014316:Tritium; C019529:polyalanine; C036501:polyvaline