2018 Volume 3 Issue 1 Pages 23-30
Chemically synthesized peptides labeled with stable isotopes are currently used as internal standards in mass spectrometry for protein quantitation. Although the use of inexpensive and crude peptides for the relative quantification of proteome dynamics has seen an increase in recent years, the synthesis of high quality internal standard peptides for measuring the absolute amount of a target protein remains expensive, making it difficult to achieve absolute protein quantification using synthetic peptides on a proteome-wide scale. Instead, a quantitative strategy using a peptide conjugate called QconCAT has been proposed as an alternative approach for absolute quantification of multiple target proteins; however, the establishment of a stable QconCAT biosynthesis system is required for its widespread use. This review focuses on the multiplexed co-synthesis approach for QconCATs using a wheat germ cell-free system with a robust translation machinery. Ultra-throughput QconCAT production in the cell-free system allows rapid construction of large-scale standard peptide libraries and accelerates attempts to quantify global proteome dynamics in various biological processes.
