Recombinant Human Ubiquitin (genbank accession number 229532), with a C-terminal extension (HS UBI-SHHHHHH), is expressed in E.coli using our cell growth medium. The protein is purified by non-denaturing methods to homogeneity as determined by SDS-PAGE. Purified protein is lyophilized under conditions preventing deleterious pH changes and packaged under vacuum. Performance is ensured for each batch by nuclear magnetic resonance (NMR) testing.

(Storage: Lyophilized protein in unopened containers may be stored for extended periods at -20°C. Once solubilized, the protein should be stored at 4°C and aseptic conditions should be maintained.)

¹H¹⁵N-HSQC NMR spectrum of uniformly ¹⁵N,¹³C,²H-labeled Ubiquitin. Sample concentration was 0.7 mM in 50 mM phosphate buffer in 90% H₂O/10% D₂O at pH=6 with 1mM NaN₃. NMR measurements were performed at 30ºC on a 500 MHz system. The spectrum was recorded with 128 msec acquisition time in the proton dimension and 75 msec acquisition time in the nitrogen dimension. All characteristic cross-peaks were observed and chemical shifts are in excellent agreement with published literature data (Wang et al., “Journal of Biomolecular NMR.” 1995, (376-382).