Figure 6.

Analyses of hydroxylated proline residues, which stabilize the collagen triple helix. A) Collagenase proteomics reported approximately 8.7% of peptides (46/525 unique peptides) modified by hydroxylated proline. Data is from duplicate LC-MS/MS analyses of tissue sections bracketing the imaging data. B) Comparison of hydroxylated proline residues in collagen peptide data. C) Example MS/MS of hydroxylated proline peptide fragmentation. D) Collagen 3A1 hydroxylated proline peptide matched by accurate mass demonstrates high signature in the tumor region of the lung tissue section. Comparison of the same putative peptide in the imaging data by accurate mass demonstrates the modified COL3A1 peptide present almost exclusively in lung adenocarcinoma patients, not in normal tissue.