S. Grzesiek and A. Bax (1992) J. Magn. Reson. 99 201-207. (Link to Article)

Minimum labelling: 15N, 13C

Dimensions: 3

Magnetisation is transferred from 1Hα and 1Hβ to 13Cα and 13Cβ, respectively, and then from 13Cβ to 13Cα. From here it is transferred first to 15NH and then to 1HN for detection. Transfer form Cαi-1 can occur both to 15Ni-1 and 15Ni, or viewed the other way, magnetisation is transferred to 15Ni from both 13i and 13i-1. Thus for each NH group there are two Cα and Cβ peaks visible. The chemical shift is evolved simultaneously on 13Cα and 13Cβ, so these appear in one dimension. The chemical shifts evolved in the other two dimensions are 15NH and 1HN.

CBCANH magnetisation transfer

Along with the CBCA(CO)NNH and HSQC this forms the standard set of experiments needed for backbone assignment. For large proteins the signal-to-noise may not be great and assignment using the HNCA, HN(CO)CA, HNCO and HN(CA)CO may form a better strategy. When using deuterated protein, the spectrum has to be recorded as an ‘out-and-back’ method and the signal-to-noise suffers even further.

CBCANH spectrum