Fig. 6.

Mirror protease strategy sequenced more long peptides and increased the ion coverage, especially for the N termini of peptides. A, Venn diagram of the correct peptides sequenced using pNovoM, pNovo+ and PEAKS. B, The distributions of the length of the peptides consistently sequenced using all three algorithms and uniquely sequenced using pNovoM. C, Relationship between the ion position and the matched ion ratio of the mirror peptide pairs (length ≤ 30). D, The distributions of the N- and C-terminal-most three-product ions for the 1,930 peptides uniquely sequenced using pNovoM. The blue numbers denote the percentage of the spectra without any ions at the corresponding ion position.