With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Giovanni Gadda from Georgia State University to elucidate the enzymology of nitronate monooxygenase, a flavin-dependent enzyme that oxidizes propionate 3-nitronate to malonic semialdehyde, nitrite and nitrate. Oxidative catalysis, speeding up reactions that involve the transfer of electrons, is fundamental to life as it is at the core of the processes involved in the extraction of useful energy from fuel, such as carbohydrates and fats. Organisms then use the extracted energy to do work, to move, and to make the various molecules of life. The involvement of flavosemiquinones in oxidative catalysis has not been studied until now. This research project focuses on nitronate monooxygenase, flavosemiquinone-dependent enzyme. This pursuit will foster the integration of experiments with the education and training of undergraduate, graduate and postdoctoral students in a variety of techniques in a multidisciplinary research environment. This will equip future generations of scientists with tools that are in high demand to fill the gap that exists between a wealth of information at the genome level and knowledge at the protein structure and function level. Educational and outreach activities beyond the laboratory will include the annual Southeast Enzyme Conference in Atlanta, the Chemistry Graduate Program and the Annual Chemistry Department Poster Day at Georgia State University.
This project will provide an opportunity to investigate the oxidation of catalytically relevant flavosemiquinones in the active sites of enzymes. The involvement of flavosemiquinones in oxidative catalysis has not been studied until now. This research project will investigate the properties of nitronate monooxygenase, an enzyme that uses flavosemiquinones in catalysis. The experimental approaches will combine steady-state and rapid kinetics, pH effects, mutagenesis and crystallography. The results will contribute to an understanding of the enzymology of nitronate monooxygenase and the reactivity of flavosemiquinones with oxygen in the active sites of enzymes. The project will also elucidate the chemical mechanism of catalysis for a member of Class H of the flavin-dependent monooxygenases, an enzymatic class that uses flavosemiquinones instead of using C4a-hydroperoxy-flavin intermediates.
