Resolution enhancement in multidimensional solid-state NMR spectroscopy of proteins using spin-state selection.
We show that the resolution of homonuclear multidimensional solid-state NMR correlation experiments can be significantly improved using transition selection and spin-state-selective polarization transfer techniques. The selection and transfer of single states allow the removal of the J-coupling contribution from the line width in both the direct and indirect spectral dimensions. This is demonstrated with a new spin-state-selective CO-Calpha correlation experiment, applied to a microcrystalline 85-residue protein. With this new sequence, all four components of the CO-Calpha cross-peaks are separated into different spectra, obtained by linear combination of four recorded data sets. Line narrowing of up to 44% was obtained on the protein sample for the spin-state-selective CO-Calpha spectrum compared to a standard spin-diffusion experiment. The new technique also allows an easy distinction between "direct" and "relayed" transfer cross-peaks.
D002247:Carbon Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010750:Phosphoproteins / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*
D002247:Carbon Isotopes; D010750:Phosphoproteins; D011506:Proteins