Probing the excited-state chemical shifts and exchange parameters by nitrogen-decoupled amide proton chemical exchange saturation transfer (HN(dec)-CEST).

Abstract

CEST-NMR spectroscopy is a powerful tool for probing the conformational dynamics of macromolecules. We present a HN(dec)-CEST experiment that simplifies the relaxation matrix, reduces fitting parameters, and enhances signal resolution. Importantly, fitting of HN(dec)-CEST profiles enables robust extraction of exchange rates as well as excited-state chemical shifts and populations.