Abstract
Desorption electrospray ionization mass spectrometry was investigated as a method to detect and identify peptides from tryptic digests of cytochrome c and myoglobin separated on ProteoChrom� HPTLC Silica gel 60 F254s plates and ProteoChrom� HPTLC Cellulose sheets. Both full scan mass spectra and data-dependent tandem mass spectra were acquired in separate plate scans and used to identify peptide ions. Peptide distributions along the development lane were mapped for each separated protein digest. Signal levels ranged over several orders of magnitude. In general, highest signal levels were obtained for the peptides with the highest Rf values on a plate, while peptides with very low Rf values were often not detected. Sequence coverages for cytochrome c were 58% for the digest separated on the silica gel plate and 72% for the separation on the cellulose sheet; myoglobin sequence coverages were 62% and 68% on silica gel and cellulose, respectively. Weak correlations between peptide hydrophilicity and Rf values on the silica gel and cellulose plates were found, with more hydrophilic peptides having lower Rf values.
