Murray State University
Molecular-Based Study of key Roles of Carbon Dioxide and the Superoxide Radical in Atmospheric Chemistry and Oxidative Damage in Biological Systems
Grade Level at Time of Presentation
Sophomore
Major
Chemistry
KY House District #
54
KY Senate District #
12
Faculty Advisor/ Mentor
Wafaa M Fawzy
Department
Chemistry
Abstract
Carbon dioxide (CO2) and reactive oxygen species (ROS), such as the superoxide anion-radical (O2-) and the nitrogen monoxide radical (NO), play major roles in atmospheric and biological processes. Recent studies showed that reactions of NO in presence of the superoxide radical lead to nitration of proteins and oxidative damage. However, the presence of CO2 prevents reactions that propagate oxidative damages in human cells, proteins, and DNA. Mechanisms were speculated to explain the role of CO2 in protecting superoxide dismutase (SODs), where SODs are enzymes that defend against oxidative stress or oxidative damage. Laboratory experiments prepared the CO4- anion-radical from interaction of CO2 and the superoxide radical at low temperatures. This study suggested that CO4- reacts readily with NO in the upper atmosphere and the ionosphere. These conclusions were supported by Rocket flights detection of the CO4- anion-radical in the ionosphere. However, up to date, we do not have answers for the following three fundamental questions: 1) How CO2 acts as an antioxidant against the superoxide radical? 2) What is the molecular structure of CO4- ? How CO4- is formed in the atmosphere and the ionosphere? Answering these questions require quantum mechanical study of interactions between CO2 and O2-. In this abstract we report the first high level quantum computational investigation on interactions between a single CO2 molecule and an individual superoxide radical that lead to formation of the CO2-O2- (CO4-) radical. We determined the molecular structure and the binding energy of CO4-. These new results suggest that CO4- plays a dual role in protecting superoxide dismutase and preventing oxidative damage by 1) Consumption of the superoxide radical, 2) Preventing progression of damaging chain reactions that cause oxidative stress. Furthermore, the relatively high stability of CO4- supports its formation from interaction of CO2 and O2- in the atmosphere and the ionosphere.
Molecular-Based Study of key Roles of Carbon Dioxide and the Superoxide Radical in Atmospheric Chemistry and Oxidative Damage in Biological Systems
Carbon dioxide (CO2) and reactive oxygen species (ROS), such as the superoxide anion-radical (O2-) and the nitrogen monoxide radical (NO), play major roles in atmospheric and biological processes. Recent studies showed that reactions of NO in presence of the superoxide radical lead to nitration of proteins and oxidative damage. However, the presence of CO2 prevents reactions that propagate oxidative damages in human cells, proteins, and DNA. Mechanisms were speculated to explain the role of CO2 in protecting superoxide dismutase (SODs), where SODs are enzymes that defend against oxidative stress or oxidative damage. Laboratory experiments prepared the CO4- anion-radical from interaction of CO2 and the superoxide radical at low temperatures. This study suggested that CO4- reacts readily with NO in the upper atmosphere and the ionosphere. These conclusions were supported by Rocket flights detection of the CO4- anion-radical in the ionosphere. However, up to date, we do not have answers for the following three fundamental questions: 1) How CO2 acts as an antioxidant against the superoxide radical? 2) What is the molecular structure of CO4- ? How CO4- is formed in the atmosphere and the ionosphere? Answering these questions require quantum mechanical study of interactions between CO2 and O2-. In this abstract we report the first high level quantum computational investigation on interactions between a single CO2 molecule and an individual superoxide radical that lead to formation of the CO2-O2- (CO4-) radical. We determined the molecular structure and the binding energy of CO4-. These new results suggest that CO4- plays a dual role in protecting superoxide dismutase and preventing oxidative damage by 1) Consumption of the superoxide radical, 2) Preventing progression of damaging chain reactions that cause oxidative stress. Furthermore, the relatively high stability of CO4- supports its formation from interaction of CO2 and O2- in the atmosphere and the ionosphere.