Capturing Excited States in the Fast‐Intermediate Exchange Limit in Biological Systems Using ¹H NMR Spectroscopy

Abstract

Changes in molecular structure are essential for the function of biomolecules.C haracterization of these structural fluctuations can illuminate alternative states and help in correlating structure to function. NMR relaxation dispersion (RD) is currently the only method for detecting these alternative,h igh-energy states.I nt his study,w ep resent av ersatile 1 HR 11 RD experiment that not only extends the exchange timescales at least three times beyond the rate limits of 13 C/ 15 NR 11 and ten times for CPMG experiments,b ut also makes use of easily accessible probes,t hus allowing ag eneral description of biologically important excited states.T his technique can be used to extract chemical shifts for the structural characterization of excited states and to elucidate complex excited states.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.

Isotope Labels Combined with Solution NMR Spectroscopy Make Visible the Invisible Conformations of Small-to-Large RNAs

“… ,,,,− In practice, CPMG experiments are solely implemented on selectively labeled RNA, and mainly from our group ,, and the Kreutz group, ,,,, though not exclusively . CEST and R 1ρ , on the other hand, have been used to great success with uniformly labeled RNA by the Al-Hashimi, ,,,− Petzold, , and Zhang ,,− groups. Moreover, Petzold and co-workers have developed a SELective Optimized Proton Experiment (SELOPE) approach that can be implemented with R 1ρ and CEST experiments using unlabeled samples.…”