Identification and mobility of deuterated residues in peptides and proteins by 2H–13C solid-state NMR

We present a solid-state NMR approach for 13C chemical-shift identification and 2H lineshape characterization of amino-acid residues in peptides and proteins deuterated by amide hydrogen/deuteron exchange. The technique exploits heteronuclear 13C–2H dipolar couplings to correlate 13C nuclei and nearby deuterons. Magic-angle spinning provides high sensitivity and 13C chemical-site resolution. The simplest version of the experiment, which is closely related to REDOR, yields a 13C spectrum permitting identification of the deuterated residues. In the full two-dimensional experiment, segmental dynamics are characterized in terms of 2H-NMR lineshapes. The technique is demonstrated on dipeptides and a 14-kDa protein, with 13C in natural abundance.