Isotope Labeling Methods for Large Systems

Abstract

A major drawback of nuclear magnetic resonance (NMR) spectroscopy compared to other methods is that the technique has been limited to relatively small molecules. However, in the last two decades the size limit has been pushed upwards considerably and it is now possible to use NMR spectroscopy for structure calculations of proteins of molecular weights approaching 100 kDa and to probe dynamics for supramolecular complexes of molecular weights in excess of 500 kDa. Instrumental for this progress has been development in instrumentation and pulse sequence design but also improved isotopic labeling schemes that lead to increased sensitivity as well as improved spectral resolution and simplification. These are described and discussed in this chapter, focusing on labeling schemes for amide proton and methyl proton detected experiments. We also discuss labeling methods for other potentially useful positions in proteins.

Site-selective 13C labeling of histidine and tryptophan using ribose

“…Studies of side chain dynamics not only complement existing backbone studies, but widen the view on certain processes and enable unique additional information of structure (Korzhnev et al 2010 ; Neudecker et al 2012 ), ring-flips (Weininger et al 2014b ; Yang et al 2015 ), histidine tautomers (Weininger et al 2017 ) and proton occupancy and transfer reactions (Hansen and Kay 2014 ; Wallerstein et al 2015 ). For studies of structure, interaction and function site selective labeling is not strictly required but often advantageous, especially for large systems (Lundstrom et al 2012a ; Ruschak and Kay 2010 ; Tugarinov and Kay 2005 ) or in solid -state (Eddy et al 2013 ).…”

Regioselective ruthenium catalysed H–D exchange using D2O as the deuterium source

“…Hydrogen isotope exchange provides the most straightforward and direct procedure toward the synthesis of labelled molecules. 4 The versatility of deuterium-labelling molecules has attracted the attention in various fields, from protein crystallography, 5 NMR, [6][7][8] MS, 9 medical imaging 10 to the elucidation of either organic 11 or bioorganic 12,13 reaction mechanisms. 14 Moreover, very recently, deuterated molecules are being studied as possible new drug candidates, incorporating deuterium atoms in the active ingredient.…”

UTOPIA NMR: activating unexploited magnetization using interleaved low-gamma detection

“…However, as the complexity of the systems studied by NMR spectroscopy grows, the challenges to get the necessary information for accurate structural analysis also increase dramatically. Instrumental improvements, isotope labeling schemes (Lundstrom et al 2012) and developments in pulse sequences (Diercks and Orekhov 2005; Farmer 1991; Frueh et al 2009; Kay et al 1990; Kay et al 1992; Kern et al 2008; Lescop et al 2007; Parella and Nolis 2010; Perez-Trujillo et al 2007; Sattler et al 1995; Schanda and Brutscher 2005; Schanda et al 2007; Szyperski et al 1996) can shorten the time for data acquisition and improve the spectral quality, thus partially compensating the growing sample complexity. Several interesting concepts such as time-shared NMR (Farmer 1991; Kay et al 1990; Kay et al 1992; Parella and Nolis 2010; Perez-Trujillo et al 2007; Sattler et al 1995), BEST (Lescop et al 2007) and SOFAST (Kern et al 2008; Schanda and Brutscher 2005; Schanda et al 2007) techniques, have been developed to use the available magnetization more effectively.…”