Experiments and strategies for the assignment of fully 13C/15N-labelled polypeptides by solid state NMR

High-resolution heteronuclear NMR correlation experiments and strategies are proposed for the assignment of fully 13C/15N-labelled polypeptides in the solid state. By the combination of intra-residue and inter-residue 13C-15N correlation experiments with 13C-13C spin-diffusion studies, it becomes feasible to partially assign backbone and side-chain resonance in solid proteins. The performance of sequences using 15N instead of 13C detection is evaluated regarding sensitivity and resolution for a labelled dipeptide (L-Val-L-Phe). The techniques are used for a partial assignment of the 15N and 13C resonances in human ubiquitin.