Sequential resonance assignment from two-dimensional inter- and intra-residue 15N-1H correlation spectra

Sequential assignment of amide resonances in proteins and peptides can conveniently be derived from two-dimensional inter-residue N-15(i)-H-1((i-1))N and intra-residue N-15(i)-H-1(i)N correlation spectra. The inter-residue N-15(i)-H-1((i-1))N correlation spectrum is generated by recording the N-15(i) frequency evolution indirectly and subsequently transferring the magnetization to H-1((i-1))N of the preceding residue for direct detection. The flow of coherence is established by the (H)N(COCAHA)-TOCSY pulse sequence. Following the path from intra-residue correlation via inter-residue correlation to the next intra-residue correlation results in sequential assignment in two dimensions. This kind of assignment protocol is most amenable to re-establishing sequential assignments of target proteins perturbed by binding of ligands or alternatively signals of peptide ligands can be traced in studies of structure-function relationships by NMR. Copyright (C) 2001 John Wiley & Sons, Ltd.