Nextgen QconCATs - MEERCAT!

Takemori N, Takemori A, Tanaka Y, Endo Y, Hurst JL, Gómez-Baena G, Harman VM, Beynon RJ. (2017) MEERCAT: Multiplexed Efficient Cell Free Expression of Recombinant QconCATs For Large Scale Absolute Proteome Quantification. Mol Cell Proteomics. 2017 Dec;16(12):2169-2183. doi: 10.1074/mcp.RA117.000284. Epub 2017 Oct 20. PubMed PMID: 29055021; PubMed Central PMCID: PMC5724179.

A major challenge in proteomics is the absolute accurate quantification of large numbers of proteins. QconCATs, artificial proteins that are concatenations ofmultiple standard peptides, are well established as an efficient means to generate standards for proteome quantification. Previously, QconCATs have been expressed in bacteria, but we now describe QconCAT expression in a robust,cell-free system. The new expression approach rescues QconCATs that previously were unable to be expressed in bacteria and can reduce the incidence of proteolytic damage to QconCATs. Moreover, it is possible to cosynthesize QconCATs in a highly-multiplexed translation reaction, coexpressing tens or hundreds ofQconCATs simultaneously. By obviating bacterial culture and through the gain of high level multiplexing, it is now possible to generate tens of thousands of standard peptides in a matter of weeks, rendering absolute quantification of a complex proteome highly achievable in a reproducible, broadly deployable system.