A GENERAL ENHANCEMENT SCHEME IN HETERONUCLEAR MULTIDIMENSIONAL NMR EMPLOYING PULSED-FIELD GRADIENTS

General pulse sequence elements that achieve sensitivity-enhanced cohe rence transfer from a heteronucleus to protons of arbitrary multiplici ty are introduced. The building blocks are derived from the sensitivit y-enhancement scheme introduced by Cavanagh et al. ((1991) J Magn. Res on., 91, 429-436), which was used in conjunction with gradient coheren ce selection by Kay et al. ((1992) J. Am. Chem. Soc., 114, 10663-10665 ), as well as from a multiple-pulse sequence effecting a heteronuclear planar coupling Hamiltonian. The building blocks are incorporated int o heteronuclear correlation experiments, in conjunction with coherence selection by the formation of a heteronuclear gradient echo. This all ows for efficient water suppression without the need for water presatu ration. The methods are demonstrated in HSQC-type experiments on a sam ple of a decapeptide in H2O. The novel pulse sequence elements can be incorporated into multidimensional experiments.