Efficient acquisition of high-resolution 4-D diagonal-suppressed methyl-methyl NOESY for large proteins.

Published

Journal Article

The methyl-methyl NOESY experiment plays an important role in determining the global folds of large proteins. Despite the high sensitivity of this experiment, the analysis of methyl-methyl NOEs is frequently hindered by the limited chemical shift dispersion of methyl groups, particularly methyl protons. This makes it difficult to unambiguously assign all of the methyl-methyl NOE crosspeaks using 3-D spectroscopy. The recent development of sparse sampling methods enables highly efficient acquisition of high-resolution 4-D spectra, which provides an excellent solution to resolving the degeneracy of methyl signals. However, many reconstruction algorithms for processing sparsely-sampled NMR data do not provide adequate suppression of aliasing artifacts in the presence of strong NOE diagonal signals. In order to overcome this limitation, we present a 4-D diagonal-suppressed methyl-methyl NOESY experiment specifically optimized for ultrasparse sampling and evaluate it using a deuterated, ILV methyl-protonated sample of the 42 kDa Escherichia coli maltose binding protein (MBP). Suppression of diagonal signals removes the dynamic range barrier of the methyl-methyl NOESY experiment such that residual aliasing artifacts in the CLEAN-reconstructed high-resolution 4-D spectrum can be further reduced. At an ultrasparse sampling rate of less than 1%, we were able to identify and unambiguously assign the vast majority of expected NOE crosspeaks between methyl groups separated by less than 5 Å and to detect very weak NOE crosspeaks from methyl groups that are over 7 Å apart.

Full Text

Duke Authors

Cited Authors

  • Wen, J; Zhou, P; Wu, J

Published Date

  • May 2012

Published In

Volume / Issue

  • 218 /

Start / End Page

  • 128 - 132

PubMed ID

  • 22464875

Pubmed Central ID

  • 22464875

Electronic International Standard Serial Number (EISSN)

  • 1096-0856

Digital Object Identifier (DOI)

  • 10.1016/j.jmr.2012.02.021

Language

  • eng

Conference Location

  • United States