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Team:PennState/NHR/introduction
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Diauxie EliminationNHR Biosensors
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Biosensors
What's a biosensor, anyway?A biosensor, in general, is a biological device that is used to sense and report for something. Biosensors can be as small as single molecules and as complex as whole organisms. Our biosensors are genetically modified E. Coli bacteria that contain modified chromosomes in addition to special expression plasmids. Sensing what?Our biosensors will be designed to report for harmful compounds, specifically Phthalates and Bisphenol A, better known as BPA. These are both contaminants in our water supply that are difficult to test for, so we intend to build biosensors to be a quick screen for high concentrations of the compounds in water. Why?Real-world relevance:Recent studies show phthalates cause negative health effects such as damage to the liver and kidneys and birth defects in rodents. Phthalates are introduced into our environment by their use as plasticizers, softeners and lubricants, for materials ranging from polyvinyl chloride (PVC) to nail polish to toddlers' toys. BPA is also found in plastics, used for the synthesis of hard plastics. Once BPA enters the human body it is confused for estrogen and parallels the effects of estrogen after attaching to the ligand binding region of the ER. Analytical detection methods for water contamination are compound specific and very costly. Having a simple and cheap tool to screen for phthalates or BPA as a general class of compounds would eliminate the cost and time involved in detection. We are using two of the natural human nuclear hormone receptor proteins that recognize a large class of ligands, and attempting to express them heterologously in E. coli. The complexity of this mammalian protein makes it difficult to express it in a prokaryote. We have two different strategies to express and use these receptors to detect compounds in E. coli. |
