A. Krushelnitsky, E. R. deAzevedo, R. Linser, B. Reif, K. Saalwächter, D. Reichert.
Direct Observation of Millisecond to Second Motions in Proteins by Dipolar CODEX NMR Spectroscopy.
J. Am. Chem. Soc. 131, 12097-12099 (2009). DOI 10.1021/ja9038888.
Abstract
In this communication, we present a novel dipolar version of the popular CODEX experiment for the study of slow ms-s motions in full-size proteins. It is based on observing rotations of the recoupled ¹H-¹⁵N dipolar tensor, which is easily accessible in ¹H-depleted and NH back-exchanged protein samples. Such samples also allow for an efficient, indirect ¹H detection of a ¹⁵N-¹H 2D correlation spectrum, in which the signal intensities are modulated as a function of the CODEX sequence parameters. In this way, we detect large-angle reorientations only for a small number of main-chain residues of the chicken α-spectrin SH3 domain, but for most NH moieties in the side-chains.