Development of an Enzyme Sensor for Reactive Oxygen Species

Undergraduate: Heta Desai

Faculty Advisor: Eric Brustad
Department: Chemistry

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All cells rely on oxidation-reduction reactions. These redox reactions generate a variety of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). ROS also have important implications in health and treating disease, as unbalanced levels of ROS in cells are linked to certain diseases. Current biological ROS sensors have high limits of detection and are restricted to specific species. ROS exist in cells for short bursts, making them difficult to measure. We were able to engineer a mutant enzyme that reacts with hydrogen peroxide to produce a detectable colorimetric signal. The unnatural amino acid p-boronophenylalanine (BoF) was incorporated into the active site of ¿¿-galactosidase to act as a molecular ¿¿¿switch¿¿¿ to activate the enzyme in the presence of ROS. ¿¿-galactosidase then catalyzes a reaction resulting in a fluorescent or colorimetric signal. While only qualitative data has been gathered, more quantitative kinetic analyses will be done in the future.