Partially-deuterated samples of HET-s(218-289) fibrils: assignment and deuterium isotope effect.

Fast magic-angle spinning and partial sample deuteration allows direct detection of1 H in solid-state NMR, yielding significant gains in mass sensitivity. In order to further analyze the spectra,1 H detection requires assignment of the1 H resonances. In this work, resonance assignments of backbone HN and Hα are presented for HET-s(218-289) fibrils, based on the existing assignment of Cα, Cβ, C', and N resonances. The samples used are partially deuterated for higher spectral resolution, and the shifts in resonance frequencies of Cα and Cβ due to the deuterium isotope effect are investigated. It is shown that the deuterium isotope effect can be estimated and used for assigning resonances of deuterated samples in solid-state NMR, based on known resonances of the protonated protein.