Use of Composite Protein Database including Search Result Sequences for Mass Spectrometric Analysis of Cell Secretome
Fig 3
Distribution of posterior error probability (PEP) and Xcorr values for PSMs of Calu-1 secretome fractionated by OFFGEL fractionator.
(A) -logPEP values are compared between each pair of peptide-spectrum matches (PSMs). The region where |Δ(-logPEP)| < 0.7 between HuDB and HFDB search results is marked grey. Spectra in blue area have PSMs in the HFDB, but not in HuDB search result. Spectra in red area have higher -logPEP value (more than 0.7) for the PSMs of HFDB than for HuDB search results. The reverse is true for the spectra in green area. (B) Distribution of XCorr values for HFDB vs. HuDB search results.