Creative Proteomics is the leading custom service provider in post-translational modification (PTM)
proteomic analysis. Based on advanced protein/peptide enrichment technology, we can help our global customers to
perform rapid and reliable deep phosphoproteome profiling. Enrichment of specifically isolate phosphoproteins or
phosphopeptides prior to high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis is
essential for successful phosphoproteomics analysis. To accelerate the success of our customers' projects
related to phosphoproteomics analysis, we offer a range of commonly used separation and phosphopeptide enrichment
strategies for customers to choose from, such as strong cation exchange chromatography (SCX), hydrophilic
interaction chromatography (HILIC), immobilized metal affinity chromatography (IMAC), titanium dioxide (TiO2)-based
phosphopeptide enrichment, and so on. Notably, our service is capable of enriching phosphorylated proteins and
peptides derived from a wide range of samples, including cells, tissues, and so on.
The necessity of phosphopeptide enrichment
For phosphoproteomics analysis services, there are two main challenges, namely, the need to optimize experimental
methods and materials to enrich phosphorylated proteins/peptides in samples and the use of quantitative proteomics
MS-based techniques. Typically, a total proteome is very complex, with a wide range of protein abundances. The
abundance of phosphorylated proteins is usually much lower and the occupancy of phosphorylation sites is usually
sub-stoichiometric. Therefore, chromatographic separation of the phosphoproteome, including
phosphoprotein/phosphopeptide enrichment, is essential for successful phosphoproteomics analysis.
Phosphopeptide enrichment service at Creative Proteomics
Due to the low abundance and wide dynamic range of most phosphoproteins, enrichment is usually required prior to
MS-based analysis. We are dedicated to providing multiple enrichment strategies to meet customers' s specific
experimental objectives. The following table lists the principles, characteristics and applications of specific
phosphopeptide enrichment methods. Among them, IMAC and TiO2-based phosphopeptide enrichment are the most
effective and frequently-used methods. Immunoprecipitation using specific phosphoserine- and
phosphothreonine-specific antibodies is primarily applied for the capturing of tyrosine-phosphorylated proteins and
peptides. In addition, we also combine different enrichment methods to obtain higher coverage of phosphoproteins or
phosphopeptides, facilitating comprehensive and reliable phosphoproteomics studies.
Comparison of some phosphopeptide enrichment methods
| Term |
Principles of phosphopeptide enrichment |
Features |
Applications |
| Strong cation exchange chromatography (SCX) |
The negatively charged phosphate groups on phosphopeptides provide a possibility to separate
phosphopeptides by the charge difference between phosphopeptides and non-phosphopeptides. |
High efficiency |
A commonly used mode of peptide separation. Used for pre-fractionation of phosphopeptides and in
combination with other enrichment methods. |
| Metal-oxide affinity chromatography (MOAC) (TiO2-based phosphopeptide
enrichment) |
Based upon the affinity of a phosphate group and metal oxides. |
High selectivity and sensitivity |
Effective and frequently-used method for phosphopeptide enrichment |
| Immobilized metal affinity chromatography (IMAC) |
Using trivalent metal ions immobilized on a stationary phase to selectively chelate negatively
charged phosphate groups of phosphoproteins or phosphopeptides based on the affinity of a phosphate
group and metal ions. |
High selectivity and sensitivity |
Effective and frequently-used method for phosphopeptide enrichment |
| Immunoprecipitation |
Using specific phosphoserine- and phosphothreonine-specific antibodies for separation of
phosphoserine and phosphothreonine peptides. |
High specificity and efficiency |
Capturing of tyrosine-phosphorylated proteins and peptides |
Advantages of our service
- Effective and affordable enrichment methods for phosphoproteins or phosphopeptides.
- Improved methods with high sensitivity are suitable for the treatment of limited samples.
- Customized enrichment strategies according to specific experimental objectives.
- Experienced protein enrichment specialists.
- The best cost-effectiveness on the market.
The comprehensive study of the phosphoproteome is heavily dependent on appropriate enrichment strategies that are
mainly carried out on the peptide level. If you are interested in our services, please contact us for more details. Our clients have direct access to our staff and prompt feedback
on their inquiries.
References
- Leitner, Alexander. "Enrichment strategies in phosphoproteomics." Phospho-Proteomics (2016):
105-121.
- Li, Xiao-Shui, Bi-Feng Yuan, and Yu-Qi Feng. "Recent advances in phosphopeptide enrichment: strategies and
techniques." TRAC Trends in Analytical Chemistry 78 (2016): 70-83.
Our products and services are for research use only.
