Fig. 2.

Mass spectrometry-based cryptide discovery and quantitation work flow: Cryptomics work flow for the high throughput discovery of cryptides would start with fractionation of tissue to enrich for low molecular weight proteome. A variety of mass spectrometry approaches can be used to identify the enriched cryptides. In most cases, the identified peptides can be mapped to the precursor proteins. Putative cryptides are tested for their bioactivities using either biochemical or cell-based assays. After the validation of bioactivity, the cryptides can be quantitated using a variety of approaches. The advantage of using mass spectrometry-based proteomic tools for quantitation is that large numbers of cryptides can be accurately quantitated in a single experiment. This information can be utilized for building higher order models of the functions of the cryptides. LC liquid chromatography, MS mass spectrometry, MALDI matrix-assisted laser desorption ionization, ESI electrospray ionization, iTRAQ isobaric tag for absolute and relative quantitation, TMT tandem mass tag, ICAT isotope coded affinity tags, MuDPIT multi-dimensional protein identification technology, TOF time of flight, MRM multiple reaction monitoring