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Show 72 Tiffanie D. Hales college of science N-Methyl-D-Aspartate receptors (NMDARs) are found in the brain and have many functions, most notably, memory formation and learning. If over-stimulated the NMDAR-expressing neurons may die, which can lead to debilitating disease-states like Alzheimer's, Parkinsons's, and Multiple Sclerosis. NMDARs consist of several important parts, such as an ion-conducting transmembrane part, a C-terminal intracellular part, and especially important for my project an extracellular ligand-binding S1/S2 part. The S1/S2 part binds glycine or glutamate and is also thought to bind snail toxins called conantokins. These conantokins inhibit NMDA receptors, which may provide hope of alternative treatments for neurodegenerative diseases. My project is attempting to determine the structure of the NMDARs when bound with the conantokins. Cloning procedures were performed in E. coli to create a protein expression vector that produces NMDAR S1/S2 protein with six histidine residues at the N-terminus. Cloned DNA was transformed into Origami B E. coli and initial experiments showed that protein was obtained. However, a large fraction of the protein was insoluble. It is necessary to obtain soluble protein in order to gain an accurate molecular picture of the NMDAR S1/S2 protein bound with conantokin. Optimal growth conditions for protein expression are being developed, by varying induction temperature, time, and concentrations of IPTG, the chemical inducer of gene expression for my system. Also, a series of different solutions have been tested in order to determine optimal extraction conditions for soluble protein; by varying pH, ionic strength, and additives such as gly-cine and glutamate, we hope to be able to increase soluble protein yield. Currently, nickle charged beads are being used to bind the six histidine residues present at the N-terminus of the S1/S2 protein. This ap-proach has helped to increase our ability to detect more precisely even small amounts of soluble protein. Once larger amounts of soluble protein are obtained, X-ray crystallography will be used to determine the exact structure of the S1/S2 portion of the NMDA receptor and its interaction with conantokins. This molecular structure will help us to make educated guesses for designing new drugs to treat patients with neurodegenerative diseases. TOWARDS A MOLECULAR PICTURE FOR A NEURORECEPTOR-SNAIL VENOM TOXIN COMPLEX WITH POTENTIAL FOR TREATMENT OF NEURODEGENERATIVE DISEASES Tiffanie D. Hales (Martin P. Horvath) Department of Biology University of Utah UNDERGRADUATE RESEARCH ABSTRACTS Martin P. Horvath |