Label-Free Quantitation and Mapping of the ErbB2 Tumor Receptor by Multiple Protease Digestion with Data-Dependent (MS1) and Data-Independent (MS2) Acquisitions

Figure 6

Coverage map of ErbB2 peptides that can significantly detect a twofold change between conditions by high resolution proteomics. ErbB2 has an N-terminal extracellular domain (1-652) which includes a dimerization (dimer) and herceptin binding (HB) domain. In addition, ErbB2 has a transmembrane domain (TM) as well as a C-terminal cytoplasmic domain which contains its kinase domain. Sites of ErbB2 phosphorylation (purple rectangles) and acetylation (green triangles) identified in this study are indicated. The 291 peptides estimated to be able to detect a significant twofold change between conditions (%CV ≤ 27 by MS1 Filtering) from all four digestion conditions were ordered beginning by amino acid to demonstrate the coverage of ErbB2 quantifiable by high resolution proteomics. The peptide coverage for each individual digestion condition is also indicated.