A set of BEST triple-resonance experiments for time-optimized protein resonance assignment

A series of sequential, intra-residue, and bi-directional BEST H-N-CA, H-N-CO, and H-N-CB pulse sequences is presented that extends the BEST concept introduced recently for fast multidimensional protein NMR [Schanda et al., J. Am. Chem. Soc. 128 (2006) 9042] to the complete set of experiments required for sequential resonance assignment. We demonstrate for the protein ubiquitin that 3D BEST H-N-C correlation spectra can be recorded on a 600 MHz NMR spectrometer equipped with a cryogenic probe in only a few minutes of acquisition time with sufficient sensitivity to detect all expected cross peaks.