Use this URL to cite or link to this record in EThOS:
Title: The radical ion chemistry of electron capture dissociation mass spectrometry of modified peptides
Author: Jones, Andrew
ISNI:       0000 0004 2720 0918
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2012
Availability of Full Text:
Access from EThOS:
Access from Institution:
The introduction of electron capture dissociation mass spectrometry in 1998 has provided a unique technique for the analysis of peptides and proteins, especially for the identification and localisation of posttranslational modifications. Despite many successes debate continues on the radical-based mechanism of ECD. This thesis explores ECD behaviour in a wide range of PTMs with the intention of furthering our knowledge of the radical-based mechanism. Studies were undertaken on the effect of 3-nitrotyrosine, which is an electron withdrawing group, on ECD. The presence of nitration dramatically decreases peptide backbone sequence coverage but results in the presence of abundant small neutral losses. The key finding is the insight provided into the hierarchy of the various proposed ECD mechanisms. ECD of cysteine bound modifications is shown to result in the fragmentation of the sulfur-modification bond and backbone sequence coverage is highly diminished when analysing S-nitrosopeptides. ECD behaviour of hydrogen-deficient radical peptides is highly dependent on gas-phase peptide structure, with electron capture typically resulting in an increase in charge-reduced precursor intensity. Comparisons of the intermolecular phospho-guanidinium bond strengths between phospho-serine, -threonine and -tyrosine were undertaken. ECD of these complexes results in the retention of the noncovalent bond allowing backbone sequence coverage.
Supervisor: Not available Sponsor: EPSRC
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QD Chemistry ; QH301 Biology ; QM Human anatomy