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Presentation Time: 10:15-10:35
Home University: UNC-Chapel Hill
Research Mentor: Matthew Redinbo, Chemistry
Program: SURF
Research Title: Investigating the Structural and Functional Diversity of Azoreductases Across the Human Intestinal Microbiome

Azo-linked compounds are ubiquitous across foods, textiles, paints, and cosmetics, as well as prodrugs that treat Inflammatory Bowel Disease (IBD). Azoreductases (AzoRs) are a family of enzymes produced by bacteria residing in the human gastrointestinal tract that reductively cleave these azo linkages; however rates of activity differ dramatically depending on the species of origin. Through metagenomic analyses, our lab has identified over 100 putative azoreductases across the human gut microbiome. In this study, we compare two novel azoreductases from Klebsiella pneumoniae (KpAzoR) and Clostridium marseille (CmAzoR) to the well-characterized Escherichia coli azoreductase A (EcAzoRA). We determined the catalytic efficiencies of these enzymes in metabolizing four sterically diverse azo dyes: methyl red, amaranth red, acid orange 7, and brilliant black. Then, we used in silico modeling to compare the structures of these enzymes in the context of their observed activities. We show disparate catalytic efficiencies across our panel of azoreductases and identify key active site differences that may account for the observed differences in activity. In future studies, we aim to characterize more azoreductases and their activities with prodrug substrates to pinpoint the azoreductases integral to the treatment of IBD. Exploring these structural and functional differences can help us better understand how azoreductases differentially activate prodrugs and may enable the manipulation of these differences for targeted therapeutics.