Ribonuclease A--a complete proton NMR fingerprint using TOCSY and NOESY experiments in water

In our attempts to obtain total sequential assignment of the 1H NMR spectrum of ribonuclease A, several published water suppression techniques were tested and assessed. The jump- and-return sequence and its echo hybrid were used with considerable success in both the TOCSY and NOESY experiments on 3mM ribonuclease A solutions. The NMR approach used here may be of general applicability for 1H NMR studies of proteins in water of concentrations under 5mM.