Linear prediction enhancement of 2D heteronuclear correlated spectra of proteins

Summary Linear prediction has been used to extrapolate the t₁ domain of natural abundance¹H–¹³C correlated two-dimensional (2D) FIDs of insulin. The FIDs were obtained by two different heteronuclear correlation experiments, one that utilizes heteronuclear multiple-quantum coherence during t₁, and one that utilizes¹³C single-quantum coherence. It is shown that the enhancement of the resolution and sensitivity in the F₁ dimension of the Fourier transform spectrum that results from the linear prediction extrapolation allows the t₁ domain to be confined to a relatively short time period where the signal intensity is at maximum. In particular, it is found that the enhancement thus obtained is sufficiently good to allow an observation of the difference between the F₁ line widths in the single-quantum and double-quantum coherence spectra.