2023 6 B1

FRET-based vitamin B6 biosensor in E coli cells

By: Livia Chung, Ike Johnson, Ahmadu Barrie

Department: Biology

Faculty Advisor: Dr. Zachary He

The presence of the bio-active form of Vitamin B6, Pyridoxal-5’-phosphate (PLP), is necessary for various physiological processes, but it can become cytotoxic if it remains unattached and accumulates without any sequestration. How cells regulate PLP homeostasis is currently not well understood. PLP biosensors can be used efficiently and conveniently to study the cell's PLP dynamics. One type of biosensor is the Fluorescence Resonance Energy Transfer (FRET). FRET works by measuring the transfer of energy between two fluorescent molecules, which are attached to a biological molecule of interest. When the biological molecule binds to its target, PLP, for example, the molecule will change its shape. This change may result in a change in the distance between the two fluorescent molecules, causing a change in the energy transfer and a change in the fluorescence signal that can be measured. The fluorescence signal can detect the target molecule's presence or concentration in a sample. We aim to use a PLP binding protein called Aspartate Aminotransferase 2 (ASP2) to engineer a FRET system in E. coli cells to test whether the FRET signals can be Detected. The FRET-based biosensor is being established. We plan to use it to monitor PLP dynamics when cells are grown at different conditions (temp, concentrations) with or without the presence of vitB6.