Morgan, Joseph William (2005-12). Development of tandem time-of-flight instrumentation for the examination of prompt photodissociation of peptides using 193-nm radiation. Doctoral Dissertation. Thesis uri icon

abstract

  • The design and incorporation of a decelerating/accelerating cell into a reflectron
    time-of-flight mass spectrometer is described for the examination of promptly-formed
    photodissociation products of peptide ions. The analytical utility of prompt 193-nm
    photodissociation was investigated for model peptides that resemble tryptic digest
    products, as well as for two sets of homologous peptides. The first of these sets include
    bradykinin, several bradykinin fragments, and two bradykinin mutants with substituted
    amino acids. Fragment ion spectra of [M + H]+, [M + Na]+, and [M + Cu]+ were
    collected for each of these peptides. The second set of homologous peptides has the
    sequence XVGVAZG, where variable amino acid X was either arginine, histidine, or
    lysine, and amino acid Z was either proline, serine, or glycine. Photofragment ion
    spectra obtained using the new mass spectrometer are compared to results of high energy
    collision induced dissociation (CID) acquired on a high performance commercial
    instrument. The advantages and disadvantages of prompt photodissociation relative to
    CID are discussed, as well as the advantages of photodissociation using the modified
    instrument geometry versus that of the post-source decay focusing method.

publication date

  • December 2005