Gas-phase chemistry of biological and metal-containing ions

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Explosive and significant advances in proteomics have been made possible by innovative technological breakthroughs and conceptual developments in biological mass spectrometry (MS). Two key technological areas that are the foundations of protein identification in MS are ion generation and collision-induced dissociation (CID) of peptides. Our proposed research continues to aim at better understanding the fundamentals of these reactions and processes, as well as the structures and energetics of the resulting ions. This knowledge is important for eventually more accurate and efficient protein sequencing and identification, especially in applications to discover and identify disease biomarkers. In particular, our objectives are to explore the structures, energetics, formation, and fragmentation chemistries of (i) molecular radical cations of oligopeptides; these ions differ from the neutral peptides by having one fewer electron, have structures and properties that are different from their protonated counterparts, and provide unique information when subject to CID-induced gas-phase microsequencing; and (ii) metalated peptides and ternary complexes; metalation imparts unique and interesting structures and chemistries to the peptides. The proposed investigations will be carried out by means of a combination of experiments, including tandem MS, threshold CID measurements, infrared multiple photon dissociation (IRMPD) spectroscopy, and DFT calculations. Tandem MS experiments will be conducted on prototype and/or commercially available mass spectrometers, including triple-quadrupole, linear ion trap, and three-dimensional ion trap. Threshold CID measurements will be conducted on a triple-quadrupole mass spectrometer fitted with a ring ion guide as q2. All of the above hardware is available in the applicant's laboratory at York University. IRMPD spectroscopic experiments will be performed in the Free Electron Laser for Infrared Experiments (FELIX) facility at the FOM-Institute for Plasma Physics "Rijnhuizen" in Nieuwegein, the Netherlands.