A 3D NOESY-(HCACO)NH experiment for the measurement of NOEs involving 1H alpha in 13C/15N-labeled proteins dissolved in H2O.

A 3D NOESY-(HCACO)NH experiment is described that transfers NOEs from 1H alpha to the backbone 1Hn in the succeeding residue for detection. Using this strategy, NOEs involving 1H alpha protons that resonate exactly at the water frequency can be detected. NOEs from an overlapping 1H alpha proton that is attached to degenerate 13C alpha can also be resolved. The performance of this approach is demonstrated for the 13C-/15N-labeled Hck/SH2 dissolved in H2O.