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Abstract
Isocitrate lyase regulator (IclR) is a transcription factor found in bacterial cells that inhibits the expression of enzymes found in the Glyoxylate Shunt, a metabolic pathway that increases the survival of bacteria. The activity of IclR is directly related to the multimer form of the protein; this multimerization is affected by the small molecules glyoxylate and pyruvate that promote different multimer forms. A Superdex™ 200 Increase Size Exclusion Column has been installed and calibrated locally for use in high pressure liquid chromatography (HPLC) analysis of samples containing isolated bacterial IclR in the presence of pyruvate or glyoxylate. The elution times of proteins with known molecular weight were collected and used to create a standard curve of molecular weight as a function of elution volume. The samples of IclR were then tested to identify multimerization patterns and compared to the results of native gel electrophoresis. HPLC chromatograms recording absorbance at 280 nm displayed multiple peaks that shifted in elution time in the presence of pyruvate or glyoxylate. The peaks appear much later than expected, but the number of peaks is consistent with the number of protein bands that appear in native gel electrophoresis.