Characterization of Recombinant Human Liver Dehydroepiandrosterone Sulfotransferase with Minoxidil as the Substrate

The study revealed that human liver dehydroepiandrosterone sulfotransferase (DHEA ST), a hydroxysteroid sulfotransferase, catalyzed the sulfate conjugation of minoxidil, an antihypertensive agent and hair growth stimulator. This was a new finding, as previously only phenol sulfotransferases were thought to catalyze this reaction. Using COS-1 cells to express DHEA ST, the researchers determined the apparent Km values for minoxidil and [35S]3′-phosphoadenosine-5′-phosphosulfate to be 3.9 mM and 0.13 μM, respectively. The enzyme's thermal stability and response to inhibitors were similar when assayed with DHEA or minoxidil. The study suggested that DHEA ST activity in the human gut and liver contributed to the overall sulfate conjugation of orally administered minoxidil, indicating its importance in understanding tissue sulfotransferase contributions to minoxidil sulfation.