Effects of deuteration on solid-state NMR spectra of single peptide crystals and oriented protein samples
作者:Zheng Long、Sang Ho Park、Stanley J. Opella
DOI:10.1016/j.jmr.2019.106613
日期:2019.12
Extensive deuteration can be used to simplify NMRspectra by "diluting" and minimizing the effects of the abundant 1H nuclei. In solution-state NMR and magic angle spinning solid-state NMR of proteins, perdeuteration has been widely applied and its effects are well understood. Oriented sample solid-state NMR of proteins, however, is at a much earlier stage of development. In spite of the promise of
Chemo-enzymatic syntheses of isotopically labelled L-amino acids
作者:Nicholas M. Kelly、Bridget C. O'Neill、John Probert、Gordon Reid、Rosamund Stephen、Ting Wang、Christine L. Willis、Peter Winton
DOI:10.1016/s0040-4039(00)78265-7
日期:1994.8
L-Alanine labelled with carbon-13 and nitrogen-15 has been prepared in good yield and high optical purity from achiral precursors using alanine dehydrogenase This versatile approach may be simply adapted for the preparation of a range of isotopically labelled amino acids and efficient syntheses of [15N]-labelled serine, valine, leucine and phenylalanine are described.
Stereoselective synthesis of stable isotope-labeled L-α-amino acids: Electrophilic amination of Oppolzer's acyl sultams in the synthesis of L-[15N]alanine, L-[15N]valine, L-[15N]leucine, L-[15N]phenylalanine and L-[1-13C, 15N]valine
Using 1-chloro-1-[N-15]nitrosocyclohexane, we have prepared five L-[alpha-N-15]amino acids. The stereoselective electophillic hydroxyamination of (S)-acylbornane-10,2-sultams, followed by Zn-o/H+ reduction, and alkaline cleavage of the chiral auxiliary, gave the amino acids in 97.2-99.5% e.e. By starting with labeled (S)-acylbornane-10,2-sultams this stereoselective route could be to prepare many C-13 and/or N-15 isotopomers of alpha-amino acids.
2D separated-local-field spectra from projections of 1D experiments
作者:Kresten Bertelsen、Jan M. Pedersen、Niels Chr. Nielsen、Thomas Vosegaard
DOI:10.1016/j.jmr.2006.10.005
日期:2007.2
A novel procedure for reconstruction of 2D separated-local-field (SLF) NMR spectra from projections of ID NMR data is presented. The technique, dubbed SLF projection reconstruction from one-dimensional spectra (SLF-PRODI), is particularly useful for uniaxially oriented membrane protein samples and represents a fast and robust alternative to the popular PISEMA experiment which correlates H-1-N-15 dipole-dipole couplings with N-15 chemical shifts. The different ID projections in the SLF-PRODI experiment are obtained from 1D spectra recorded under influence of homonuclear decoupling sequences with different scaling factors for the heteronuclear dipolar couplings. We demonstrate experimentally and numerically that as few as 2-4 1D projections will normally be sufficient to reconstruct a 2D SLF-PRODI spectrum with a quality resembling typical PISEMA spectra, leading to significant reduction of the acquisition time. (c) 2006 Elsevier Inc. All rights reserved.