Thiolate is a highly reactive species critical to the function of many enzymes. We attempted to model the chemistry of two of these enzymes with cysteine in solution at a high pH. To study cysteine proteases, we increased the pH of a cysteine and 4- nitrophenylacetate solution to create a visible color change when thiolyzed that was monitored through UV-Vis spectroscopy to determine rate constants. To study transferases, we attempted to model two reactions. The first was a methyl transfer from guanine to cysteine which mimicked O6-alkylguanine-DNA alkyltransferase. The second was activation of halogenated hydrocarbons by a mechanism similar to glutathione Stransferase. Samples were analyzed by NMR spectroscopy. Results showed change in rate constants with the addition of cysteine in the protease reactions and possible formation of products in the activation of halogenated hydrocarbons. Attempts to model methyl transfer were not successful.
Advisor(s) or Committee Chair
Dr. Kevin Williams
Physical Sciences and Mathematics
Turner, Emily Michelle, "Modeling Thip;ate Enzyme Chemistry with Cysteine at a High pH" (2009). Mahurin Honors College Capstone Experience/Thesis Projects. Paper 268.