Fig. 1
From: The plasma peptidome
The human endogenous tryptic peptides and/or phosphopeptides where precursor intensity is greater than E4 (10,000) arbitrary detector counts after selecting the best fit of MS/MS spectra from 2+ or 3+ ions and selecting the single best peptide fit for each MS/MS fragmentation spectrum (Filter 2). a the SEQUEST algorithm; b the X!TANDEM algorithm