4.3. PMF identification of proteins on PE-UHMW PMF and peptide sequencing after “on-polymer” digestion revealed two major problems:PMF identification based on the oretical peptide assignment is critical and sufficient abundant peptide PSD or CID spectra are-due to the insulating properties of PE-UHMW–difficult to obtain. However,very complex mass spectra including the potential peptides of all enzymatically cleaved proteins from synovia were acquired. After comparing theoretical protein digests to measured m/z values, tentatively protein names, assigned after intact protein MSI experiments, were confirmed. Manual data interpretation of fragmented peptides confirmed those results. Again all detected peptides were found
Preferentially on sharp edges and folded areas.