Degree Name

MS (Master of Science)

Program

Chemistry

Date of Award

12-2014

Committee Chair or Co-Chairs

Marina Roginskaya

Committee Members

Scott Kirkby, David Close

Abstract

The carbonate radical anion (CO3•-, CR) is an important reactive oxygen species produced in vivo by one-electron oxidation of CO2 or bicarbonate, constituents of the major physiological buffer. It was demonstrated for the first time by using an HPLC-based analysis of low-molecular products of DNA damage that CRs react with DNA 2΄-deoxyribose by the hydrogen abstraction mechanism. CRs exhibit a ~ 800-fold preference for one-electron oxidation of guanine over hydrogen abstraction from DNA sugar, in sharp contrast with •OH. CRs also have, as compared to •OH, an increased preference for the H1΄ abstraction, which is the most thermodynamically favorable due to the highest stability of the respective deoxyribosyl radical but kinetically the slowest due to low solvent accessibility, by the expense of the decreased preference for the H5΄ abstraction. All these findings are in agreement with the characteristics of CR as a potent oxidant and selective hydrogen abstractor.

Document Type

Thesis - Open Access

Copyright

Copyright by the authors.

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