A program for the evaluation of 3D spectra applied to the sequential assignment of BPTI utilizing 3D TOCSY-NOESY

The determination of three-dimensional structures of proteins by NMR requires the assignment of their super(1)H NMR spectrum, performed mostly by means of 2D NMR. The main problem is to find the correct sequential connectivities, a step which is time-consuming and usually hindered by spectral overlap. We want to show that the use of homonuclear 3D spectroscopy is of advantage for the automatic assignment. The advantage of using cross peaks of 3D TOCSY-NOESY spectra lies in the reduction of the number of possible nodes due to the better characterization of the connectivities.