Supplementary Figure 5: Detailed analysis of an unknown protein complex detected in the pyruvate kinase protein standard.
From: An informatic framework for decoding protein complexes by top-down mass spectrometry
The data and fragment map from the 3-tier tandem MS procedure for the detected complex is shown in panels (a-c), followed by the graphical fragment ion map of the ejected monomer that corresponds to G1U7S4, the uncharacterized protein phosphoglycerate mutase 2, PGAM2, N-terminally acetylated (red), and identified with an E-value of 6 × 10−12 and a C-score of 45. In the MS2 spectrum, a set of satellite peaks ~128 Da lower in mass are consistent with a C-terminal lysine cleavage; the 9+ species is shown in the inset (b). After identification of this complex as PGAM2, addition of the uncleaved monomer to the new CORUM/Proteoform and CORUM/MPC hybrid databases led to the result with a MPC-score of 2,983 shown in (d) which emerged from the Fig. 1 process.
