Investigation of Quinone Reductase and Nitroreductase Activities with the AzoC Enzyme

The AzoC enzyme found in Clostridium perfringens is a known azoreductase.  The ability to reduce azo dyes is particularly useful as azo dyes are widely used in textiles, yet can prove harmful to the environment and living organisms.  Interestingly, another azoreductase, AzoR from Escherichia coli, has been shown to reduce quinone compounds, as well as azo dyes.  Quinone compounds are derived from aromatic compounds such as benzene and naphthalene and some can also serve as dyes.  Previous mixed enzyme studies have also indicated that Clostridium perfringens possesses nitroreductase properties.  Our hypothesis is that AzoC possesses broad activities that include azo, quinone, and nitroreduction.  To support our hypothesis, spectrophotometric methods will be used to determine quinone reductase activity using menadione (2-methylnaphthalene-1,4-dione), lawsone (2-hydroxy-1,4-naphthoquinone), anthraquinone-2,6-disulfonate, anthraquinone-2-sulfonate, and 2-methyl-1,4-benzoquinone; and nitroreductase activity using 4-nitrobenzoic acid, 2,4,6-trinitrotoluene, and 1-amino-7-nitrofluorine.  Due to similar studies with the AzoR enzyme and previous studies with Clostridium perfringens, it is predicted that AzoC will also possess quinone reductase and nitroreductase properties. The conclusion of the study will enhance our understanding of the role of Clostridium perfringens in the human intestine.