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You searched for +publisher:"Georgia Tech" +contributor:("Bridgette A. Barry"). Showing records 1 – 3 of 3 total matches.

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Georgia Tech

1. Offenbacher, Adam R. Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds.

Degree: PhD, Chemistry and Biochemistry, 2011, Georgia Tech

Tyrosyl radicals can facilitate proton-coupled electron transfer (PCET) reactions that are linked to catalysis in many biological systems. One such protein system is ribonucleotide reductase (RNR). This enzyme is responsible for the conversion of ribonucleotides to deoxyribonucleotides. The beta2 subunit of class Ia RNRs contains a diiron cluster and a stable tyrosyl radical (Y122*). Reduction of ribonucleotides is dependent on reversible, long-distance PCET reactions involving Y122* located 35 Å from the active site. Protein conformational dynamics are postulated to precede diiron cluster assembly and PCET reactions in RNR. Using UV resonance Raman spectroscopy, we identified structural changes to histidine, tyrosine, and tryptophan residues with metal cluster assembly in beta2. With a reaction-induced infrared spectroscopic technique, local amide bond structural changes, which are associated with the reduction of Y122*, were observed. Moreover, infrared spectroscopy of tyrosine-containing pentapeptide model compounds supported the hypothesis that local amide bonds are perturbed with tyrosyl radical formation. These findings demonstrate the importance of the amino acid primary sequence and amide bonds on tyrosyl radical redox changes. We also investigated the function of a unique tyrosine-histidine cross-link, which is found in the active site of cytochrome c oxidase (CcO). Spectrophotometric titrations of model compounds that mimic the cross-link were consistent with a proton transfer role in CcO. Infrared spectroscopic data support the formation of tyrosyl radicals in these model compounds. Collectively, the effect of the local structure and the corresponding protein dynamics involved in tyrosyl radical-mediated PCET reactions are illustrated in this work. Advisors/Committee Members: Bridgette A. Barry (Committee Chair), Jake D. Soper (Committee Member), Jim Spain (Committee Member), Nils Kroger (Committee Member), Paul H. Wine (Committee Member).

Subjects/Keywords: Cytochrome c oxidase; Escherichia coli; UV resonance Raman spectroscopy; FT-IR spectroscopy; Infrared spectroscopy; Proton-coupled electron transfer; Oxidation-reduction reaction; Protein engineering; Tyrosine

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Offenbacher, A. R. (2011). Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/39473

Chicago Manual of Style (16th Edition):

Offenbacher, Adam R. “Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds.” 2011. Doctoral Dissertation, Georgia Tech. Accessed September 18, 2020. http://hdl.handle.net/1853/39473.

MLA Handbook (7th Edition):

Offenbacher, Adam R. “Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds.” 2011. Web. 18 Sep 2020.

Vancouver:

Offenbacher AR. Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2020 Sep 18]. Available from: http://hdl.handle.net/1853/39473.

Council of Science Editors:

Offenbacher AR. Protein structural changes and tyrosyl radical-mediated electron transfer reactions in ribonucleotide reductase and model compounds. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/39473

2. Kasson, Tina Michelle Dreaden. High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair.

Degree: PhD, Chemistry and Biochemistry, 2012, Georgia Tech

Oxidative stress is a natural consequence of photosynthetic oxygen evolution and redox enzyme processes. Trp oxidation to N-formylkynurenine (NFK) is a specific, reactive oxygen species (ROS)-mediated reaction. This thesis work describes the identification and functional characterization of NFK in oxygen evolving Photosystem II (PSII). Although proteomics studies have confirmed NFK modifications in many types of proteins, limited knowledge on the biochemical significance exists. In vitro studies in thylakoids and PSII membranes were used to establish a correlation between oxidative stress, NFK formation, and photoinhibition. The in vivo effect of preventing Trp oxidation to NFK was assessed by site-directed mutation in the cyanobacteria Synechocystis sp. PCC 6803. This work provides insight into the role of NFK in photosynthetic oxygen evolution and photoinhibition. Based on the current knowledge of NFK, ROS, and repair, a new model is described. In this modified model for photoinhibition and repair, NFK plays a role in signaling for turnover of damaged proteins. NFK may play a similar role in replacement of damaged proteins in other systems. Advisors/Committee Members: Bridgette A. Barry (Committee Chair), David Collard (Committee Member), Ingeborg Schmidt-Krey (Committee Member), Wendy Kelly (Committee Member), Yomi Oyelere (Committee Member).

Subjects/Keywords: Tryptophan; Reactive oxygen species; Photosynthesis; Photosystem II; N-formylkynurenine; Synechocystis 6803; Amino acids; Plants Effect of light on

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kasson, T. M. D. (2012). High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/45759

Chicago Manual of Style (16th Edition):

Kasson, Tina Michelle Dreaden. “High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair.” 2012. Doctoral Dissertation, Georgia Tech. Accessed September 18, 2020. http://hdl.handle.net/1853/45759.

MLA Handbook (7th Edition):

Kasson, Tina Michelle Dreaden. “High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair.” 2012. Web. 18 Sep 2020.

Vancouver:

Kasson TMD. High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair. [Internet] [Doctoral dissertation]. Georgia Tech; 2012. [cited 2020 Sep 18]. Available from: http://hdl.handle.net/1853/45759.

Council of Science Editors:

Kasson TMD. High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair. [Doctoral Dissertation]. Georgia Tech; 2012. Available from: http://hdl.handle.net/1853/45759

3. Keough, James M. Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions.

Degree: PhD, Chemistry and Biochemistry, 2013, Georgia Tech

Proton coupled electron transfer reactions often involve tyrosine residues, because when oxidized, the phenolic side chain deprotonates. Tyrosine Z (YZ) is responsible for extracting electrons in a stepwise fashion from the oxygen evolving-complex in order to build enough potential to oxidize water. This process requires that each step YZ must deprotonate and reprotonate in order to maintain the high midpoint potential that is necessary to oxidize the oxygen-evolving complex, which makes YZ highly involved in proton coupled electron transfer reactions. In this thesis YZ has been studied within oxygen-evolving photosystem II utilizing electron paramagnetic resonance spectroscopy to monitor the tyrosyl radical that is formed upon light excitation. Kinetic analysis of YZ has shed light on the factors that are important for PSII to carry out water oxidation at the oxygen-evolving complex. Most notably the strong hydrogen-bonding network and the midpoint potential of YZ have been shown to be integral aspects of the water splitting reactions of PSII. By studying YZ within oxygen-evolving PSII, conclusions are readily applied to the native system. Advisors/Committee Members: Bridgette A. Barry (Committee Chair), Adegboyega K. Oyelere (Committee Member), Facundo Fernandez (Committee Member), Ingeborg Schmidt-Krey (Committee Member), Mostafa El-Sayed (Committee Member).

Subjects/Keywords: Photosystem II; Proton coupled electron transfer reactions; Tyrosine Z; Tyrosine D; YZ; YD; Water oxidation; Photosynthesis; Power resources Research; Photosynthetic reaction centers

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Keough, J. M. (2013). Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/47738

Chicago Manual of Style (16th Edition):

Keough, James M. “Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions.” 2013. Doctoral Dissertation, Georgia Tech. Accessed September 18, 2020. http://hdl.handle.net/1853/47738.

MLA Handbook (7th Edition):

Keough, James M. “Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions.” 2013. Web. 18 Sep 2020.

Vancouver:

Keough JM. Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2020 Sep 18]. Available from: http://hdl.handle.net/1853/47738.

Council of Science Editors:

Keough JM. Redox active tyrosines in photosystem II: role in proton coupled electron transfer reactions. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/47738

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