Solution NMR of water on protein surfaces

Specialized water-suppression NMR pulse sequences and heteronuclear three-dimensional NMR have now made it possible to observe cross relaxation between the protons of water molecules and protons on the surface or in the interior of biological molecules. The cross-relaxation characteristics at each site allow loosely and tightly bound waters to be distinguised and limits on the residence lifetimes to be placed. These observations are affording a new view of the nature of protein hydration.