A role for glutathione in reactions between oxidants and proteins
dc.contributor.advisor | James A. Thomas | |
dc.contributor.author | Mallis, Robert | |
dc.contributor.department | Biochemistry, Biophysics and Molecular Biology | |
dc.date | 2018-08-23T03:01:59.000 | |
dc.date.accessioned | 2020-06-30T07:32:32Z | |
dc.date.available | 2020-06-30T07:32:32Z | |
dc.date.copyright | Sat Jan 01 00:00:00 UTC 2000 | |
dc.date.issued | 2000-01-01 | |
dc.description.abstract | <p>This dissertation examines the role of reduced glutathione (GSH) in the oxidation of proteins. Carbonic anhydrase III is a cytosolic protein which is S-glutathiolated in cells under oxidative stress. The pure protein was found here to be S-glutathiolated by two oxidants, 2,2'-Azobis(2-amidinopropane)dihydrochloride (AAPH) and hydrogen peroxide (H2O2). At physiologically relevant molar ratios of GSH to protein, GSH was found to mediate protection of carbonic anhydrase III from irreversible oxidation via S-glutathiolation. Both oxidants were found to react directly with the protein. S-glutathiolation. appears to result from the formation of an activated protein thiol that reacts with GSH;H-Ras, a low molecular weight G-protein that regulates proliferation and differentiation in cells, may be regulated by oxidative events. For this reason, oxidative modifications of the cysteine residues of H-Ras were studied. The pure protein was modified on multiple thiols when incubated with thiol oxidants. H2O2 + GSH was found to S-glutathiolate H-Ras on at least one cysteine, while either diamide + GSH or glutathione disulfide (GSSG) was found to S-glutathiolate at least two H-Ras cysteines. The NO donor S-nitrosoglutathione caused S-nitrosylation of H-Ras on four cysteine residues;Within NIH/3T3 cells overexpressing H-Ras, H-Ras was S-glutathiolated on multiple thiols by diamide. At least one of the cysteine residues modified in cells by diamide is normally lipidated, suggesting a role for oxidation in regulating the membrane association of H-Ras. In NIH/3T3 cells overexpressing H-Ras, S-nitrosocysteine was found to cause both S-nitrosylation and S-glutathiolation of H-Ras. Thus, oxidative modification of H-Ras can occur simultaneously on multiple thiols and by multiple mechanisms;The effect of S-nitrosocysteine on low molecular weight thiols and soluble proteins in NIH/3T3 cells was also studied. S-nitrosocysteine was found to be an effective S-nitrosating agent, causing S-nitrosylation of glutathione and proteins. S-nitrosocysteine was also found to be an effective oxidant, causing formation of glutathione disulfide, cysteine-glutathione disulfide, cystine, S-glutathiolated and S-cysteylated proteins. The biological effects of S-nitrosocysteine are likely to be mediated not only through nitrosative, but also oxidative events. Thus cellular GSH pools interact significantly with S-nitrosocysteine and may be a factor in cell-specific variations in responses to S-nitrosothiols.</p> | |
dc.format.mimetype | application/pdf | |
dc.identifier | archive/lib.dr.iastate.edu/rtd/13916/ | |
dc.identifier.articleid | 14915 | |
dc.identifier.contextkey | 6950763 | |
dc.identifier.doi | https://doi.org/10.31274/rtd-180813-15270 | |
dc.identifier.s3bucket | isulib-bepress-aws-west | |
dc.identifier.submissionpath | rtd/13916 | |
dc.identifier.uri | https://dr.lib.iastate.edu/handle/20.500.12876/67442 | |
dc.language.iso | en | |
dc.source.bitstream | archive/lib.dr.iastate.edu/rtd/13916/r_9962832.pdf|||Fri Jan 14 20:04:10 UTC 2022 | |
dc.subject.disciplines | Biochemistry | |
dc.subject.keywords | Biochemistry | |
dc.subject.keywords | biophysics | |
dc.subject.keywords | and molecular biology | |
dc.subject.keywords | Biochemistry | |
dc.title | A role for glutathione in reactions between oxidants and proteins | |
dc.type | article | |
dc.type.genre | dissertation | |
dspace.entity.type | Publication | |
relation.isOrgUnitOfPublication | faf0a6cb-16ca-421c-8f48-9fbbd7bc3747 | |
thesis.degree.level | dissertation | |
thesis.degree.name | Doctor of Philosophy |
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