A reappraisal of the 6-O-desmethylnaproxen-sulfating activity of the human cytosolic sulfotransferases.
In this study, we aimed to obtain a comprehensive account of the human cytosolic sulfotransferases (SULTs) that are capable of sulfating 6-O-desmethylnaproxen (O-DMN), a major metabolite of naproxen. Of the 13 known human SULTs tested, 7 (SULT1A1, SULT1A2, SULT1A3, SULT1B1, SULT1C2, SULT1C4, and SULT1E1) displayed O-DMN-sulfating activity, when analyzed using an elevated substrate concentration (500 μmol·L-1) together with 14 μmol·L-1of the sulfate donor, 3'-phosphoadenosine-5'-phosphosulfate (PAPS). At 10 μmol·L-1O-DMN concentration, however, only SULT1A1 and SULT1A3 displayed detectable activity, with the former being nearly 2 orders of magnitude more active than the latter. A pH-dependence study indicated that SULT1A1 exhibited a broad pH optimum spanning pH 5.5-7. Kinetic parameters of the sulfation of O-DMN by SULT1A1 were determined. The production and release of sulfated O-DMN was demonstrated using cultured human HepG2 hepatoma cells and Caco-2 colon carcinoma cells. Moreover, assays using human organ specimens revealed that the O-DMN-sulfating activities present in the cytosols of liver and small intestine (at 502.5 and 497.2 pmol·min-1·(mg protein)-1, respectively) were much higher than those detected for the cytosols of lung and kidney. Taken together, these results provided relevant information concerning the sulfation of O-DMN both in vitro and in vivo.
a Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Science Campus, Toledo, OH 43614, USA.
Fatemah A
FA
Alherz
a Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Science Campus, Toledo, OH 43614, USA.
Daniyah A
DA
Almarghalani
a Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Science Campus, Toledo, OH 43614, USA.
Noor A
NA
Hussein
a Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Science Campus, Toledo, OH 43614, USA.|b Department of Biochemistry and Applied Biosciences, University of Miyazaki, Miyazaki 889-2192, Japan.
Katsuhisa
K
Kurogi
a Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Science Campus, Toledo, OH 43614, USA.
Ming-Cheh
MC
Liu
D018938:Caco-2 Cells; D003600:Cytosol / Q000201:enzymology*; D057075:Enzyme Assays; D056945:Hep G2 Cells; D006801:Humans; D007700:Kinetics; D009288:Naproxen / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D013431:Sulfates / Q000737:chemistry*; D015238:Sulfotransferases / Q000378:metabolism*
D013431:Sulfates; D009288:Naproxen; D015238:Sulfotransferases; C034451:desmethylnaproxen
6-O-desmethylnaproxen; 6-O-déméthyle naproxène; SULT; SULTs; cytosolic sulfotransferase; naproxen; naproxène; sulfatation; sulfation; sulfotransférase cytosolique