Conformational characterization of poly(l-phenylalanine) in the solid state by 13C CP-MAS NMR spectroscopy

Abstract High-resolution 13 C NMR spectra of poly( l -phenylalanines) in the solid state taking antiparallel β-sheet, α-helix and ω-helix forms were recorded by the cross polarization—magic angle spinning method. It was found that 13 C chemical shifts of each carbon are significantly displaced, depending on conformational change, and that the screw sense of the ω-helix is right-handed.