Date of Award

Spring 5-2019

Degree Type

Honors College Thesis

Department

Chemistry and Biochemistry

First Advisor

Faqing Huang

Advisor Department

Chemistry and Biochemistry

Abstract

Coenzyme A (CoA) is an important enzyme cofactor involved in acyl transfer reactions. Recently, CoA and its various thioesters were found to exist at the 5’ end of RNA molecules. Although the function of these molecules is still unknown due to difficulties in their isolation, their existence at the 5’ RNA end reveals potentially novel biological roles of RNA. We are exploiting the broad substrate tolerance of the medium chain fatty acid-coenzyme A ligase (FadK), hypothesizing that this enzyme will accept biotinylated medium chain fatty acid substrates, creating biotin-tagged CoA-RNA. This modified CoA-RNA can later be captured using streptavidin affinity chromatography, allowing for the analysis and eventual determination of the sequence of CoA-RNA in bacterial cells. The focus of this project is to adequately clone, express, and purify the enzyme, followed by subsequent analysis of enzymatic activities, including the substrate spectrum and enzyme kinetics. Using recombinant DNA technology, we have successfully cloned, expressed, and purified FadK. Although there is no direct and simple way to analyze the activity of the purified enzyme, we hypothesize that AMP deaminase (AMPD) could be used to convert adenosine monophosphate (AMP) released during the thioesterification reaction to inosine monophosphate (IMP), which would cause UV absorbance changes that are easily monitored by UV spectrophotometry. When fully developed, this technique could be used to analyze and quantitate AMP, and therefore may have broad applications in analyzing enzyme-catalyzed reactions involving carboxyl group activation such as amino acid activation and fatty acid metabolism.

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Included in

Biochemistry Commons

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