Abstract 1577 A Human Gut Microbial Sulfotransferase Modulates Concentrations of Acetaminophen Sulfate and Other Phenolic Sulfates

Sulfation is one of the two main phase II detoxification pathways in eukaryotes that transform non-polar compounds into hydrophilic metabolites. This process is catalyzed by sulfotransferases. Mammalian sulfotransferases use only 3'-phosphoadenosine 5' phosphosulfate (PAPS) as a sulfate donor. Less understood are microbial sulfotransferases which catalyze similar reactions but can utilize sulfate donors other than PAPS. Recent literature shows that enzymes from the gut microbes can transform human metabolites and other chemicals/ xenobiotics that interact with the GI tract and can modulate concentrations of several host metabolites.[DS1] [DS2] Our aim is to understand the role of gut microbial sulfotransferases in the possible modulation of physiologically relevant phenolic and phenolic sulfate metabolites. In this study, we characterized a sulfotransferase from the prevalent gut microbe Bacteroides vulgatus using steady state kinetics, colorimetric and fluorometric enzyme assays, high performance liquid chromatography, and mass spectrometry. Most microbial sulfotransferases studied so far have been characterized with artificial or non-physiological sulfate donors. Here we show that unlike mammalian sulfotransferases, BvST accepts many physiologically relevant molecules as sulfate donors. Some of these are acetaminophen-sulfate, dopamine-sulfate, and para-cresol-sulfate. Additionally, with intact protein mass spectrometry, we demonstrate that the enzyme gets transiently sulfated during catalysis and we identify the possible site of sulfation via trypsin digestion and LC-MS. We also found that many biologically relevant molecules including para-coumaric acid, acetaminophen, dopamine, 4-ethyl phenol, and para cresol act as sulfate acceptors for BvST. This study shows that an enzyme from an abundant gut microbe is able to modulate concentrations of xenobiotics, host derived metabolites, and molecules produced by the human gut microbes. These results imply that such gut microbial enzymes might affect host level detoxification of molecules like acetaminophen which were previously thought to be solely detoxified via human sulfotransferases. [DS1]We are not yet doing that. [DS2]Change this to the version I am adding We thank the New College of Interdisciplinary Arts and Sciences (NCIAS) at Arizona State University and the Biodesign Center for Health Through Microbiomes at Arizona State University for their funding support.