ABSTRACT
Establishing high-resolution structures of biological macromolecules in heterogeneous environments by MAS solid-state NMR is an important challenge where development of advanced experimental procedures is in high demand. Promising new methods take advantage of samples with extensive (2)H, (13)C, and (15)N isotope labelling, effectively diluting (1)H spins. In many cases, a sufficient amount of (1)H at exchangeable sites cannot be re-established during the purification procedure, hence it is necessary to exploit also the potential of (2)H as a starting point in pulse sequences, capitalizing on its short T1 as compared to (13)C, and to detect carbon or proton spins as appropriate. Here we present a new method that enables the required high-efficiency (2)H to (13)C or (15)N polarization transfer to be accomplished under the limited (2)H rf power conditions using current (1)H, (2)H, (13)C and (15)N quadruple-resonance MAS NMR instrumentation.
