PhosphoScout™


PhosphoScout™ is a global, quantitative phospho-proteomics service developed to investigate cellular signal transduction pathways and their response to drug treatment. State-of-the-art quantitative mass spectrometry is used as an elegant, unbiased way to comprehensively analyze proteome-wide in vivo phosphorylation patterns.

PhosphoScout™ allows annotation and quantification of regulated phosphorylation sites in living cells, animal models and patient samples. Since the majority of targeted cancer drugs influence a cell’s signal transduction pathways, quantification of phosphorylation patterns in relation to drug administration delivers detailed insights into a compound’s cellular mode of action.

PhosphoScout™ service combines high-end quantitative mass spectrometry techniques with unrivaled software applications to:

  • Perform mode of action analysis of your targeted drug
    Use system-wide modeling of signaling events and investigate your drug’s influence on cellular phosphorylation patterns to significantly decrease development times in drug discovery
  • Predict therapeutic outcome
    Investigate the effects of cross-talk on your drug’s efficiency and unveil potential mechanisms of cellular resistance. Use PhosphoScout™ to overcome the fundamental problem of non-responsiveness to a multitude of compounds or to reveal additional therapeutic applications
  • Discover novel biomarkers
    Apply PhosphoScout™ as a valuable tool to discover predictive biomarkers that foretell the therapeutic outcome in a patient, which in turn allows a personalized therapy approach
  • Validate your target and identify new drug targets
    Investigate your target’s downstream effect in relevant disease models like knock-out or knock-in cells or identify new druggable proteins

PhosphoScout™ does not require phospho-specific antibodies but delivers global, unbiased analysis of the phospho-proteome by measuring the relative quantity of more than 15,000 phosphorylation sites in a single experiment.

Although an estimated one-third of all cellular proteins are thought to be reversibly phosphorylated at some point, only a small subset of in vivo phosphorylation sites has been discovered so far. Furthermore, phospho-specific antibodies are available for only a minor fraction of these described phosphorylation sites, which means comprehensive, detailed analysis of global cellular phosphorylation patterns based on antibody-dependent approaches is nearly impossible.

PhosphoScout™ Technology

To detect differences in abundance between different samples, proteins must be labeled using various isotopes that can be differentiated due to their mass using mass spectrometry. PhosphoScout™ can be performed on any given cell line or tissue. For a proteome-wide analysis of phosphorylation signals, phospho-peptides are enriched prior to mass spectrometry using strong cationic exchange chromatography in combination with IMAC (Immobilized Metal Affinity Chromatography) or TiO2.

The excellent analytical performance of quantitative phospho-proteomics using LC-MS/MS combines highly sensitive measurements with the exceptional mass accuracy necessary to identify phospho-peptides. The resulting mass spectrometric data is analyzed using MaxQuant – a quantitative proteomics software (developed at the Max Planck Institute of Biochemistry in Martinsried) designed for analyzing high resolution MS data.


Labeled protein extracts from untreated and drug treated cells or tissues are enzymatically cleaved. Strong cationic exchange chromatography is used in combination with IMAC or TiO2 to enrich the phospho-peptides from the respective cell or tissue. Subsequent mass spectrometry and bioinformatic analyses allow relative quantification and comparison of phospho-peptide patterns between different samples.

KINAXO has applied its PhosphoScout™ technology in projects for pharmaceutical partners. PhosphoScout™ is also being used in an extensive drug efficiency study.


Further reading:

Olsen JV et al., 2006, Cell, 127(3), 635-648  abstract
Cox J & Mann M, 2008, Nature Biotechnology 26, 1367-1372  abstract
Cox J & Mann M, 2007, Cell, 130(3), 395-398  abstract
Krüger M et al., 2008, Cell 134(2), 353-364  abstract