QconCAT

QconCAT

 

QconCAT is a powerful technique along with AQUA for the absolute quantification of target peptides and thus proteins. A QconCAT protein is expressed in E.coli containing tryptic peptides from the proteins of interest. These peptides are predicted to yield good signal intensity following electrospray ionisation. The QconCAT protein can be expressed heavy and then spiked into samples at known amounts. Comparing the signal between heavy QconCAT peptide and the sample peptide can then be used to determine the absolute quantification of the protein. Its principle is illustrated below.

QconCAT

See also: Carroll KM, Simpson DM, Eyers CE, Knight CG, Brownridge P, Dunn WB, Winder CL, Lanthaler K, Pir P, Malys N, Kell DB, Oliver SG, Gaskell SJ, Beynon RJ. (Dec 2011) Absolute quantification of the glycolytic pathway in yeast: deployment of a complete QconCAT approach. in Mol Cell Proteomics. 10(12):M111.007633.