17O NMR chemical shifts and quadrupole coupling constants in solid poly(L-alanine)s determined using a high-speed MAS technique

The solid-state 17O NMR spectra of L-alanine-residue containing polypeptides were measured by magic-angle spinning (MAS) at 25 kHz. NMR parameters such as the chemical shift, quadrupolar coupling constant and asymmetry parameter are obtained from the spectra. The relationship between the hydrogen-bonded structure and these NMR parameters is clarified. The hydrogen-bonding structures are related to the quadrupolar coupling constants and the chemical shift values.