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

We present a solid-state NMR approach for C-13 chemical-shift identificatio n and H-2 lineshape characterization of amino-acid residues in peptides and proteins deuterated by amide hydrogen/deuteron exchange. The technique exp loits heteronuclear C-13-H-2 dipolar couplings to correlate C-13 nuclei and nearby deuterons. Magic-angle spinning provides high sensitivity and C-13 chemical-site resolution. The simplest version of the experiment, which is closely related to REDOR, yields a C-13 spectrum permitting identification of the deuterated residues. in the full two-dimensional experiment, segment al dynamics are characterized in terms of H-2-NMR lineshapes. The technique is demonstrated on dipeptides and a 14-kDa protein, with C-13 in natural a bundance. (C) 1999 Elsevier Science B.V. All rights reserved.