Determination of amide exchange rates by measurement of 2D NMR line-broadening
Infant, Newborn, Diseases
A novel NMR method is presented that allows direct quantitative measurement of hydrogen exchange rates from a single 2D NMR experiment. The method is based on the fact that first-order exchange of amide protons with deuterons results in line-broadening in the t1 dimension of a 2D experiment. The time scale of the experiment can be varied to optimize the measurement of exchange rates that are slower than 1 min-1. The method is demonstrated on a small peptide, angiotensin II, and it is shown that rates, on the order of 10-1-10-2 min-1, are obtained by the 2D line-broadening method and that these agree with the rates obtained by sequentially acquired ID spectra.