Triple resonance solid state NMR experiments with reduced dimensionality evolution periods.

Two solid state NMR triple resonance experiments which utilize the simultaneous incrementation of two chemical shift evolution periods to obtain a spectrum with reduced dimensionality are described. The CO N CA experiment establishes the correlation of (13)C(i-1) to (13)C alpha(i) and (15)N(i) by simultaneously encoding the (13)CO(i-1) and (15)N(i) chemical shifts. The CA N COCA experiment establishes the correlation (13)Ca(i) and (15)CO(i) to (13)C alpha(i-1) and (15)N(i-1) within a single experiment by simultaneous encoding of the (13)C alpha(i) and (15)N(i) chemical shifts. This experiment establishes sequential amino acid correlations in close analogy to the solution state HNCA experiment. Reduced dimensionality 2D experiments are a practical alternative to recording multiple 3D data sets for the purpose of obtaining sequence-specific resonance assignments of peptides and proteins in the solid state. Copyright 2001 Academic Press.