Introduction
Ubiquitination is an important post-translational modification, which has a central function in protein regulation
and mediates various cellular processes such as DNA repair, cell cycle control, apoptosis, inflammatory responses
and antigen presentation. Protein ubiquitination, a stepwise biological event, is mainly mediated by the
ubiquitin-proteasome system, which is involved in 80% to 85% of protein degradation in eukaryotes. It is initiated
by the ubiquitin-activating enzyme E1, whose cysteine residue binds to the C-terminal glycine residue of ubiquitin
in an ATP-dependent manner. Then, the ubiquitin-conjugating enzyme E2 catalyzes the transfer of activated ubiquitin
from E1 to the cysteine residue of E2. Finally, the ubiquitin ligase E3 catalyzes the transfer of ubiquitin by
forming an isopeptide bond between the lysine ε-amino group of the substrate and the C-terminal glycine of
ubiquitin. Notably, E3 determines the substrate specificity during ubiquitination and can specifically recognize
protein substrates, which also determines that ubiquitination analysis is a key biochemical technique for developing
new drugs and new targets.
Fig. 1. Schematic diagram of ubiquitination.
(Liu J, et al., 2021)
Our Services
Creative Proteomics is pleased to introduce a professional ubiquitinated protein analysis platform
to help you solve your ubiquitination identification and quantification problems.
At Creative Proteomics, we use HPLC to pre-separate samples and enrich for ubiquitinated peptides
using antibodies against specific residue structures. Specifically, an anti-K-ε-GG antibody was used to identify and
enrich the K-ε-GG group, which is the residue of two glycines generated at the modification site of lysine by
trypsin digestion of ubiquitinated proteins (K-GG). In addition to this, 2-3 different enzymes are used to digest,
thus ensuring full coverage of the ubiquitin peptide site.
With cutting-edge equipment and expertise in protein sequencing and mass spectrometry, we provide one-stop
ubiquitinated protein analysis service. You only need to tell us the purpose of your experiment and send your
samples to us, we will take care of all the follow-up matters of the project.
The simple process of our service includes:
- Protein extraction.
- In-gel or in-solution enzymatic digestion.
- Ubiquitinated peptide enrichment.
- Peptide separation.
- Mass spectrometry analysis.
- Ubiquitination site data analysis.
What Can We Offer You?
- Identify ubiquitinated specific proteins.
- Identify specific sites that ubiquitinate specific proteins.
- Identify specific lysine residues of ubiquitinated proteins.
- Identify specific sites of ubiquitination modification to recognize lysine residues.
Advantages of Our Services
Our analytical services strictly follow ICH Q6B guidelines with the following attractive features.
- High-throughput: Identify and quantify up to thousands of proteins at once.
- High precision and accuracy: The modified peptide segment and its modification site can be accurately
determined.
- 100% coverage: Specific antibodie and 2-3 enzymes are used to enrich ubiquitinated peptides and digest
interested protein, thus ensuring full coverage.
- Analysis of multiple modification types: Different types of polyubiquitination can be analyzed.
- Fast turnaround time: A complete report you received in 5-7 days.
- Customized service: Analysis protocols will be tailored according to your project and sample type.
Sample Requirements
- Tissue samples: Plant tissue samples > 200 mg, blood samples > 1 mL (with EDTA for anticoagulation of
plasma), serum > 0.5 mL, urine> 2 mL, animal tissue samples >1 g, cell samples > 5X107
cells, microorganisms > 200 mg (dry weigh).
- Protein samples > 1 mg.
Thanks to our powerful mass spectrometry sequencing platform, Creative Proteomics provides a
one-stop ubiquitinated protein analysis service. Our experienced scientists work with you to develop tailor-made
analytical solutions. Please feel free to contact us with any questions
regarding ubiquitinated protein analysis.
References
- Liu J, Cheng Y, Zheng M, et al. (2021) Targeting the ubiquitination/deubiquitination process to
regulate immune checkpoint pathways. Signal Transduct Target Ther. 6(1):28.
- Lee K A, Hammerle L P, Andrews P S, et al. (2011) Ubiquitin ligase substrate identification through
quantitative proteomics at both the protein and peptide levels. J Biol Chem. 286(48):41530-41538.
