Skip to main content
. Author manuscript; available in PMC: 2017 Sep 8.
Published in final edited form as: J Proteome Res. 2013 Mar 8;12(4):1560–1568. doi: 10.1021/pr300453t

Figure 8.

Figure 8

(A) Estimating the score distribution for PSMs formed by the cyclic peptide Tyrocidine A (single-stage MS). Solid line shows the distribution of scores of 109 peptides that are randomly generated. The dots show the MS-DPR p-values. (B) Similar results for the MultiStage score defined in the multistage de novo sequencing paper, 4 for 107 peptides. Red dashed lines represent the scores of the correct peptide. The figure shows that MS-DPR p-values and empirical p-values are well correlated. Moreover, the p-value of the correct peptide is lower for multi-stage score (5e – 13) single-stage score (5e – 07), illustrating the advantage of multi-stage mass spectrometry. MS-DPR enables comparisons between arbitrary scoring functions. (C) Similar results for the score distribution for PSMs formed by the branch-cyclic peptide A21978C2 (single-stage MS).