Proteomics
Protein biomarkers
SELDI-TOF MS spectra (click for larger version)
Modern techniques of protein analysis and identification are being used in attempts to discover new protein biomarkers of disease and toxicity. Biomarkers may be used to improve diagnosis, provide earlier detection of disease, and to give an insight into the disease process.
Our projects are based on the use of two main techniques:
SELDI-TOF MS ProteinChip application
SELDI-TOF mass spectrometry is rapid in its ability to produce protein profiles from complex mixtures and provide a means to compare relative levels of protein expression. Proteins of interest are then purified in order to facilitate their identification by fragmentation mass spectroscopy. We have used this technique with some success to identify protein biomarkers from plasma.
Pathway analysis of estrogen-responsive proteins (click for larger version)
Label-free Quantitative Proteomics employs nanoflow liquid chromatography coupled to electrospray ionisation mass spectrometry which provides a means to identify, directly, protein biomarkers from complex samples. We have used this approach successfully in the analysis of estrogen-responsive proteins in breast cancer cells and is currently being applied to the analysis of lung, skin and plasma samples.
Development of a universally-applicable approach for the generation of protein-specific antibodies
Ion Trap mass spectrometer (click for larger version)
Initial validation of proteomic changes can often be supported by immunochemical evdience (e.g. western blotting). To this end, we have developed a novel approach to the efficient production of highly specific antibodies against proteins.
The approach, which is based on targeting a minimal epitope at the C-terminus of proteins, has been shown to have advantages over the use of monoclonal antibodies or polyclonal antibodies raised against purified proteins. Panels of antibodies have been produced in this way to target human and rodent cytochrome P450 enzymes, as well as a number of other enzymes involved in drug metabolism.
We have recently extended this approach to target a variety of proteins expressed by Streptococcus pyogenes to demonstrate its broad utility. Raising antibodies in this way is fast and efficient and thus meets the increasing need for suitable antibodies necessary in follow up studies to support the proteomic identification of proteins of interest.
Expression of 20 proteins by Streptococcus pyogenes
