Other applications. The BE block can be incorporated into any pulse sequences involving the magnetization transfer through the Cα spins. For example, the hNCAHA and hNco-CAHA experiments previously used for backbone and sidechain assignments under >90 kHz MAS condition are the possibilities. Considering the fact that Ca T2' of fully protonated PR in proteoliposomes, one of the most challenging targets, was reported to be ~13 ms under 100 kHz MAS , being even longer than that for GB1 as measured in this study, we anticipate the utility of the BE-experiment for a wide range of similar membrane protein targets. The BE experiments do not necessarily need the Cα chemical shift to be evolved. It has been recently shown that the HNcocaNH and HNcacoNH experiments with their five-dimensional derivatives are the powerful means for the large protein sequential assignments . The BE-block can be added to them to obtain the Cβ chemical shift information even for T2'-limited systems.