Protein Sequence Tags (PST®) (gel-free proteomics)
The identification of new targets for drug discovery and new biomarkers for diagnosis and prognosis of disease is a major challenge and requires new technology solutions to deal with the complexities of biological samples. PST® provides
a novel integrated solution particularly suited to the detection of membrane
proteins and other cellular and body fluid proteins which are good diagnostic
and drug targets.
The PST® protein expression profiling technology uses a combination of peptide sampling and LC-MS/MS that allows analysis of complex protein mixtures. The technology is based on a proprietary labelling chemistry that in theory isolates between 8-9 peptides from each protein in a mixture, and is capable of providing >97% coverage of all predicted proteins (depending on the genome).
Each standard PST® analysis can typically identify and measure several hundred proteins (both soluble and membrane). When membrane enrichment is used, typically over 50% of proteins identified are membrane proteins. PST® is also compatible with other separation approaches where increased complexity allows higher numbers of protein identifications.
PST® is suitable for the analysis of all classes of proteins
and specifically provides a sharp focus on the pharmaceutically relevant
membrane and nuclear proteins which may be useful as new diagnostic or
prognostic markers of disease, new therapeutic targets, or markers of drug
efficacy, toxicity and resistance.
Quantitative Protein Sequence Tags (qPST™ )
This approach relies on isotopic labelling methodology and is a further
development of the above PST® procedure. Briefly, the qPST™ process
consists of a chemical sample preparation step, a labelling step using the
light and heavy isotope tags followed by the pooling of the labelled samples.
After purification, the pooled mixture is digested enzymatically and the
labelled peptide mixture is separated into 7 fractions by SCX chromatography
prior to MS analysis. The labelled peptide pairs are quantified in MS mode
by comparing the intensity of their peaks.
The Benefits of PST®/qPST™
- Combined enzymatic cleavage and chemical labelling procedure to reduce sample complexity and the isolation of below 10 peptides per protein.
- LC-MS/MS analysis of sampled peptides labelled with differential isotopic tags for control and disease samples and powerful bioinformatics provides unambiguous identification and relative quantification of proteins present in complex mixtures.
- Identifies and quantifies difficult proteins and is particularly
suitable for nuclear and membrane proteins that are the target
of most drugs.
- Applicable to complex mixtures of proteins from cells, tissues and body fluids.
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Services
Proteome Sciences offers strategic collaborations using
PST® and qPST™ to pharmaceutical, diagnostic and theranostic
partners in biomarker discovery for the identification of differentially
expressed membrane and other proteins as diagnostic and/or drug
targets.
GEL FREE SYSTEMS FOR MEMBRANE AND NUCLEAR PROTEINS
Site last updated: 5th January 2009
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