SLOW AMIDE PROTON-EXCHANGE RATES FROM THE LINE WIDTHS IN A SINGLE 2-DIMENSIONAL H-1-NMR SPECTRUM

A method is presented that allows a quantitative determination of chemical exchange rates of the order of reciprocal hours from the line widths of the signals in a single two-dimensional H-1 nuclear magnetic resonance spectrum. The method is based on a linear prediction analysis of the time domain signal and a nonlinear least squares fit of the entire frequency domain signal. The applicability of the method is demonstrated by the determination of the exchange rates of seven slowly exchanging amide protons in the des-[Phe(B25)] mutant of human insulin.