Three-dimensional protein NMR TROSY-type 15N-resolved 1HN_1HN NOESY spectra with diagonal peak suppression

An earlier two-dimensional NOESY experiment with diagonal peak suppression in the H-1(N) - H-1(N) region is extended to three dimensions by including N-15 evolution while maintaining the TROSY approach throughout. The technique suppresses all anti-TROSY resonances by appropriate pulse sequence elements and for large molecules at high fields possible semi- and anti-TROSY artifacts are further suppressed by virtue of much shorter transverse relaxation times for these components. The new technique is demonstrated using an N-15-labeled protein sample, RAP 17-97 (N-terminal domain of alpha 2-macroglobulin Receptor Associated Protein), in H2O at 500 MHz. (C) 2000Academic Press.