Chemical shifts for Cα and Cβ carbons are of particular importance because, with their relatively dispersed chemical shifts, they can serve as a "finger print" in identifying the type of the amino acid residues. For solid-state NMR under a fast MAS condition, a protocol proposed by Pintacuda and co-workers is widely used . They used the CANH and CAcoNH experiments to identify the Cα chemical shifts, and caCBcaNH and caC-BcacoNH to identify the Cβ chemical shifts, where the atom name with a lower case designates the one to which the coherence is transferred, but the chemical shift is not encoded. Despite fully functional, this protocol entails two limitations: the caCBcaNH and caCBcacoNH experiments require long spinechoes. The Cβ chemical shifts are encoded by convering an inphase operator, Cα ! , to an anti-phase operator, 2Cα " Cβ # , which is then reconverted back into the in-phase state before detection. Assumign 𝐽 $%$& is ~35 Hz, this interconversion requires ~29 ms (= 1/𝐽 $%$& ) of the transverse evolution. This strongly limits its application to non-crystalline samples, e.g. membrane proteins in liposomes, with relatively short T2', suffering from the sensitivity drop. Another problem is that since the resonances are matched up using the H-N resonances for sequential signal assignment, degeneracy of the H-N resonances exponentially increases the complexity of the assignment process. Four-dimensional (4D) spectra, such as 4D-caCBCANH and caC-BCAcoNH, would help reducing such complexity with a price of the lower sensitivity and increasing measurement time. Nonuniform sampling (NUS) and projection spectroscopy are of limited use for the low-sensitivity, peak-degenerated data often encountered in MAS NMR of solid proteins. Thus, methods that provide amino acid type information without implementing the 4D evolution is strongly preferable.