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The function of the electron transfer chain in Escherichia coli succinate dehydrogenase
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- Author / Creator
- Tran, Quang
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Complex II, or succinate dehydrogenase, is a vital component of aerobic life. Its function is critical for both the tricarboxylic acid cycle and the mitochondrial respiratory chain since it catalyzes the oxidation of succinate to fumarate, liberating two electrons that feed into the lipid-soluble quinone pool. Despite over 50 years of research, and the fact that it is the simplest of all the mitochondrial respiratory chain complexes, there is still much to learn regarding the catalytic mechanism of complex II. In recent years, there has been a renewed interest in this enzyme, due to its central role in a subset of human cancers, hereditary paraganglioma and pheochromocytoma. For my research, I chose Escherichia coli succinate dehydrogenase as the model system due to its innumerable similarities to mitochondrial complex II. In chapter two, I examine key residues that enable succinate dehydrogenase to interact with its quinone substrate. Chapters three and four focus on the function of the single b-type heme in the enzyme, and its potential role, or lack thereof, in enzyme catalysis and suppression of reactive oxygen species production. In chapter five, microsecond freeze-hyperquench experiments are utiilized to empirically quantify electron transfer rates through the succinate dehydrogenase iron-sulfur cluster relay, and examine the control that endergonic electron tunneling steps exert on those rates.
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- Graduation date
- Fall 2011
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.