Minimizing the water resonance in biological NMR: characterization and suppression of intermolecular dipolar interactions by multiple-axis gradients

Experiments were carried out to examine the creation and detection of intermolecular multiple-quantum coherences between water molecules. Specifically, the influence of variable-angle pulsed field gradients and the magnetization caused by the intermolecular MQ coherences was investigated with respect to poor water suppression in biomolecular NMR studies of isotopically labeled proteins in aqueous solution.