Assignment of amide proton signals by combined evaluation of HN, NN and HNCA MAS-NMR correlation spectra

摘要

In this paper, we present a strategy for the H-1(N) resonance assignment in solid-state magic-angle spinning (MAS) NMR, using the alpha-spectrin SH3 domain as an example. A novel 3D triple resonance experiment is presented that yields intraresidue H-N-N-C-alpha correlations, which was essential for the proton assignment. For the observable residues, 52 out of the 54 amide proton resonances were assigned from 2D (H-1-N-15) and 3D (H-1-N-15-C-13) heteronuclear correlation spectra. It is demonstrated that proton-driven spin diffusion (PDSD) experiments recorded with long mixing times (4 s) are helpful for confirming the assignment of the protein backbone N-15 resonances and as an aid in the amide proton assignment. [References: 21]