A. Krushelnitsky, E. R. deAzevedo, R. Linser, B. Reif, K. Saalwächter, D.
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.
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.