Solid-State NMR Structure Determination from Diagonal-Compensated Proton-Proton Restraints.
Related Articles Solid-State NMR Structure Determination from Diagonal-Compensated Proton-Proton Restraints.
J Am Chem Soc. 2014 Jul 2;
Authors: Linser R, Bardiaux B, Andreas LB, Hyberts SG, Morris VK, Pintacuda G, Sunde M, Kwan AH, Wagner G
Abstract
We report acquisition of diagonal-compensated protein structural restraints from 4-dimensional solid-state NMR spectra on extensively deuterated and 1H back-exchanged proteins. To achieve this, we use homonuclear 1H-1H correlations with diagonal suppression and non-uniform sampling (NUS). Suppression of the diagonal allows the accurate identification of cross-peaks which are otherwise obscured by the strong autocorrelation or whose intensity is biased due to partial overlap with the diagonal. The approach results in unambiguous spectral interpretation and relatively few but reliable restraints for structure calculation. In addition, the diagonal suppression produces a spectrum with low dynamic range for which ultra-sparse-NUS data sets can be readily reconstructed, allowing straightforward application of NUS with only 2% sampling density with the advantage of more heavily sampling time-domain regions of high signal intensity. The method is demonstrated here for two proteins, ?-spectrin SH3 microcrystals and hydrophobin functional amyloids. For the case of SH3, suppression of the diagonal results in facilitated identification of unambiguous restraints and improvement of the quality of the calculated structural ensemble compared to non-diagonal-suppressed 4D spectra. For the only partly assigned hydrophobin rodlets, the structure is yet unknown. Applied to this protein of biological significance with large inhomogeneous broadening, the method is shown to allow identification of unambiguous crosspeaks that are otherwise obscured by the diagonal.
PMID: 24988008 [PubMed - as supplied by publisher]
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