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dc.contributor.advisorLehotay, Denis C.en_US
dc.creatorAhmed, Mohamed S.en_US
dc.date.accessioned2007-11-26T10:43:15Zen_US
dc.date.accessioned2013-01-04T05:09:13Z
dc.date.available2007-12-12T08:00:00Zen_US
dc.date.available2013-01-04T05:09:13Z
dc.date.created2007-12en_US
dc.date.issued2007-12-12en_US
dc.date.submittedDecember 2007en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-11262007-104315en_US
dc.description.abstractHereditary Hemochromatosis (HH) is an inherited recessive autosomal disorder characterized by accumulation of excess iron. When iron binding proteins become saturated, concentrations of free, or non-transferrin-bound iron (NTBI) rise, a condition thought to be responsible for the adverse effects associated with HH. To investigate that disturbing iron homeostasis plays a role in free radical injury in HH, protein carbonyls were found to be 1-7 times higher in patients with HH than in controls, with the greatest increases being observed in untreated HH patients with high ferritin and >90% transferrin saturation with iron. An Unpaired t test revealed a P value of 0.0278 (P< 0.05), which is considered to be statistically significant. Our data showed a significant positive correlation (linear relationship) between the level of carbonyl content and ferritin concentration in plasma samples from patients with HH. In vitro oxidation of transferrin and ferritin standards with hydrogen peroxide and excess iron, followed by immobilized trypsin digestion (Poroszyme), high-resolution LC-MS/MS analysis (Q-TOF Ultima, Waters) and MS/MS data processing (PEAKS, Bioinformatics Solution), identified several tryptic peptides containing oxidized Met,Trp and His residues. Mapping of the oxidized ferritin residues showed them to be located on the inner face of each sub-unit, the face directed toward the ferritin core where iron is normally stored. Using the same methodology, oxidized residues were subsequently detected in ferritin and transferrin isolated from plasma samples of patients severely affected with HH. Comparing of MS/MS spectra of in vitro oxidized samples that have most fragment ion peaks in common with oxidized peptide MS/MS spectra from samples of patients with HH revealed a significant correlation between the two. These data show that elevated NTBI may be involved in oxidative modification of the iron binding proteins, ferritin and transferrin, and that such modifications may play a significant role in the pathophysiology of HH.en_US
dc.language.isoen_USen_US
dc.subjectTransferrinen_US
dc.subjectMALDI-TOF MSen_US
dc.subjectQ-TOF LC-MS/MSen_US
dc.subjectFerritinen_US
dc.titleDetection of in vitro and in vivo oxidative modifications of ferritin and transferrin by mass spectrometry : hereditary hemochromatosis as a modelen_US
thesis.degree.departmentPathologyen_US
thesis.degree.disciplinePathologyen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US


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