Structural Studies on Ionic Liquid/Water/Peptide Systems by HR-MAS NMR Spectroscopy

The present work reports on an assessment of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy for structural investigations of peptides dissolved in aqueous ionic liquids. Highly resolved one- and two-dimensional NMR spectra are obtained that allow for complete proton resonance assignments of both the peptides as solutes and the ionic liquids as solvents. Successful application of the HR-MAS method facilitates for the first time high-resolution NMR analysis of complex ionic liquid/peptide systems at the molecular level, mainly on the basis of chemical-shift changes.