LABELED UBIQUITIN STANDARDS for NMR spectroscopy Ubiquitin, the 76-residue protein is found both as free monomer in eukaryotic cells, and covalently attached to itself and other proteins. The C-terminus of ubiquitin forms an isopeptide bond with the amino group of a lysine side chain in a target protein. In this way proteins can be covalently modified by the addition of ubiquitin that alters the target protein's function. If a chain of multiple copies of ubiquitin is atached to a target proteins this appears to target the protein for degradation by the large intacellular protease, the 26S proteasome. However, recent evidence suggests that ubiquitination can target proteins for other fates besides degradation by the proteasome. We offer the ubiquitin in three variants each at different variations of labeling by stable isotopes 15N and 13C with 98% of incorporation and 2D, with 80 and 98% of deuteration, by your choice.
Human ubiquitin gene was RT-PCR amplified and cloned with (His)6 encoded tag at C-terminus. The protein is expressed in E.coli grown in isotopically enriched media with following isolation from soluble fraction on Ni-NTA resin, eluted by imidazole and subsequently purified to 98-99% homogeneity by size exclusion chromatography.
We use WILMAD 535-PP-7 and other NMR tubes. The tube is filled by argon sealed and the cap is placed on the sealed end. The sealed end is labeled by sticker. For transport, the bottom of the tube is protected by another cap. Please remove this cap from the opposite end before use. For safest delivery, the tube is packed into the original metal container.
The spectra were recorded using Varian Unity Inova 600 MHz spectrometer (data is kindly provided by Dr. Perrtu Permi, Institute of Biotechnology, University of Helsinki, Finland). Click to the spectra to see the full size image.
The protein is demonstrated to participate in the stress response into the endoplasmic reticulum of eucaryotic cells.
C domain of ERp29 gene is expressed with (His)6 tag at N-terminus, in E.coli grown in corresponding isotopically enriched media with following isolation from soluble fraction on Ni-NTA resin, eluted by imidazole and subsequently purified to 98-99% homogeneity by ion exchange chromatography followed by heparin sepharose chromatography.