Spectral editing of two-dimensional magic-angle-spinning solid-state NMR spectra for protein resonance assignment and structure determination

TitleSpectral editing of two-dimensional magic-angle-spinning solid-state NMR spectra for protein resonance assignment and structure determination
Publication TypeJournal Article
Year of Publication2012
AuthorsSchmidt-Rohr K, Fritzsching KJ, Liao SY, Hong M
Journal TitleJournal of Biomolecular NMR
Volume54
Pages343-353
Date Published12
Type of ArticleArticle
ISBN Number0925-2738
Accession NumberWOS:000312210100003
Keywordsc-13 nmr, CH selection, chemical-shift-anisotropy, cpmas nmr, dynamics, immunoglobulin-binding domain, MAS, membrane-proteins, nmr, organic-matter, Protein secondary structure, REDOR, secondary, Spectral editing, spectroscopy, structure
Abstract

Several techniques for spectral editing of 2D C-13-C-13 correlation NMR of proteins are introduced. They greatly reduce the spectral overlap for five common amino acid types, thus simplifying spectral assignment and conformational analysis. The carboxyl (COO) signals of glutamate and aspartate are selected by suppressing the overlapping amide N-CO peaks through C-13-N-15 dipolar dephasing. The sidechain methine (CH) signals of valine, lecuine, and isoleucine are separated from the overlapping methylene (CH2) signals of long-chain amino acids using a multiple-quantum dipolar transfer technique. Both the COO and CH selection methods take advantage of improved dipolar dephasing by asymmetric rotational-echo double resonance (REDOR), where every other pi-pulse is shifted from the center of a rotor period t(r) by about 0.15 t(r). This asymmetry produces a deeper minimum in the REDOR dephasing curve and enables complete suppression of the undesired signals of immobile segments. Residual signals of mobile sidechains are positively identified by dynamics editing using recoupled C-13-H-1 dipolar dephasing. In all three experiments, the signals of carbons within a three-bond distance from the selected carbons are detected in the second spectral dimension via C-13 spin exchange. The efficiencies of these spectral editing techniques range from 60 % for the COO and dynamic selection experiments to 25 % for the CH selection experiment, and are demonstrated on well-characterized model proteins GB1 and ubiquitin.

URL<Go to ISI>://WOS:000312210100003
DOI10.1007/s10858-012-9676-8
Alternate JournalJ. Biomol. NMR