Suppression of sampling artefacts in high-resolution four-dimensional NMR spectra using signal separation algorithm

► A four-dimensional version of signal separation algorithm has been presented. ► 4D HCCH-TOCSY and 4D C, N-edited NOESY were performed on a 13.4 kDa protein. ► Up to 90% sampling noise reduction was achieved in 4D HCCH-TOCSY. ► Sampling density as low as 0.16% were used. ► A transverse relaxation optimization of HMQC increases sensitivity up to 18%.