PTM & Phosphoproteomics
Cellular Signaling Dynamics & Kinase Mapping
Yatiri Bio's B2B PTM & Phosphoproteomics Service isolates and quantifies post-translational modifications, focusing on phosphorylated peptides via Immobilized Metal Affinity Chromatography (IMAC). By measuring modified residues rather than absolute protein abundance, we construct active kinase signaling network maps to identify drug target interactions and resolve cellular escape paths responsible for resistance.
Why Measure modifications Over Abundance?
While global proteomics defines absolute protein concentrations, it does not represent protein activation states. In signal transduction, proteins are rapidly turned on or off through enzymatic addition of chemical modifications—predominantly phosphorylation.
In cancer, hyperactive kinase networks drive rapid cellular proliferation and escape mechanisms. Measuring phosphoproteins allows drug discovery researchers to monitor exactly which signaling cascades are active, mapping the functional efficacy of tyrosine kinase inhibitors (TKIs) and other molecular targeted therapeutics.
Scientific Workflow: IMAC Peptide Enrichment
Because phosphorylated peptides exist at low abundance relative to the total cellular proteome, they must be chemically enriched prior to mass spectrometry injection.
Yatiri Bio incorporates high-selectivity Fe-NTA or Ti-Reagent Immobilized Metal Affinity Chromatography (IMAC) columns to isolate negatively charged phosphate groups on serine (Ser), threonine (Thr), and tyrosine (Tyr) residues. This protocol achieves enrichment purity levels exceeding 90%, allowing deep coverage of the intracellular signaling landscape.
Workflow Execution Phases
- Cell Lysis & Protein Extraction: Addition of phosphatase inhibitors to freeze active phosphorylation states.
- Trypsin Digestion: Digestion of proteins into peptide fragments.
- IMAC Enrichment: Separation and collection of phosphorylated peptides using metal affinity columns.
- LC-MS/MS Runs: Injecting enriched fractions into high-resolution tandem mass spectrometers.
- Kinase Activity Profiling: Bioinformatic reconstruction of active upstream kinases using database scoring engines.
Phosphoproteomics Buyer Questions
When is phosphoproteomics better than abundance profiling?
Use phosphoproteomics when the program needs active signaling, kinase activity, or bypass pathway data rather than total protein abundance alone.
How does it connect to patient selection?
Phosphorylation patterns can identify pathway activation states that separate sensitive and resistant models, supporting biomarker hypotheses for trial enrichment.
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PTM analyses are structured around input quality, required enrichment depth, and quantitative labeling (such as TMT vs LFQ).