Multiplexed absolute quantification in proteomics using artificial QCAT proteins of concatenated signature peptides

Nat Methods. 2005 Aug;2(8):587-9. doi: 10.1038/nmeth774.


Absolute quantification in proteomics usually involves simultaneous determination of representative proteolytic peptides and stable isotope-labeled analogs. The principal limitation to widespread implementation of this approach is the availability of standard signature peptides in accurately known amounts. We report the successful design and construction of an artificial gene encoding a concatenation of tryptic peptides (QCAT protein) from several chick (Gallus gallus) skeletal muscle proteins and features for quantification and purification.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens
  • Gene Expression Profiling / methods*
  • Muscle Proteins / analysis*
  • Muscle Proteins / metabolism
  • Peptide Mapping / methods*
  • Peptides / analysis
  • Peptides / metabolism
  • Proteome / analysis*
  • Proteome / metabolism
  • Proteomics / methods*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Staining and Labeling / methods


  • Muscle Proteins
  • Peptides
  • Proteome