AbstractsBiology & Animal Science

Mass spectrometers may be utilized to generate and detect fragmentation patterns of peptides and proteins to acquire mass spectra that allow for accurate amino acid sequence characterization and localization of post-translational modifications. Conventional activation methods utilize collisions with neutral gas molecules to collisionally activate these ions but have some drawbacks, being dependent on charge state and amino acid sequence characteristics. More recent activation methods include radical transfer as well as ultraviolet photodissociation, the latter of which impart higher energy into target ions providing more extensive fragmentation patterns and more sequence information. In the following research all of these activation methods were explored with peptide and protein cations as well as various combinations of such methods to investigate their benefits and limitations. In summary, ultraviolet photodissociation provides the most diverse fragmentation patterns of all researched. Combining radical transfer and subsequent ultraviolet photodissociation termed “hybrid activation” generated interesting effects such as spectral simplification as well as constructive inclusion of fragment ions lacking in ultraviolet photodissociation. Included in this thesis are those interesting findings. Advisors/Committee Members: Brodbelt, Jennifer S. (advisor), Mullins, Charles B (committee member).