Publications

• Kinetic analysis of bile acid sulfation by stably expressed human sulfotransferase 2A1 (SULT2A1).

  Huang J., Bathena S.P., Tong J., Roth M., Hagenbuch B., Alnouti Y.

  Human sulfotransferase 2A1 (SULT2A1) is a member of the hydroxysteroid sulfotransferase (SULT2) family that mediates sulfo-conjugation of a variety of endogenous molecules including dehydroepiandrosterone (DHEA) and bile acids. In this study, we have constructed a stable cell line expressing SULT2 ... >> More

  Human sulfotransferase 2A1 (SULT2A1) is a member of the hydroxysteroid sulfotransferase (SULT2) family that mediates sulfo-conjugation of a variety of endogenous molecules including dehydroepiandrosterone (DHEA) and bile acids. In this study, we have constructed a stable cell line expressing SULT2A1 by transfection into HEK293 cells. The expression system was used to characterize and compare the sulfation kinetics of DHEA and 15 human bile acids by SULT2A1. Formation of DHEA sulfate demonstrated Michaelis-Menten kinetics with apparent K(m) and V(max) values of 3.8 muM and 130.8 pmol min(-1) mg(-1) protein, respectively. Sulfation kinetics of bile acids also demonstrated Michaelis-Menten kinetics with a marked variation in apparent K(m) and V(max) values between individual bile acids. Sulfation affinity was inversely proportional to the number of hydroxyl groups of bile acids. The monohydroxy- and most toxic bile acid (lithocholic acid) had the highest affinity, whereas the trihydroxy- and least toxic bile acid (cholic acid) had the lowest affinity to sulfation by SULT2A1. Intrinsic clearance (CL(int)) of ursodeoxycholic acid (UDCA) was approximately 1.5- and 9.0-fold higher than that of deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA), respectively, despite the fact that all three are dihydroxy bile acids. << Less

  Xenobiotica 40:184-194(2010) [PubMed] [EuropePMC]

  This publication is cited by 12 other entries.

• Structural and chemical profiling of the human cytosolic sulfotransferases.

  Allali-Hassani A., Pan P.W., Dombrovski L., Najmanovich R., Tempel W., Dong A., Loppnau P., Martin F., Thornton J., Edwards A.M., Bochkarev A., Plotnikov A.N., Vedadi M., Arrowsmith C.H.

  The human cytosolic sulfotransfases (hSULTs) comprise a family of 12 phase II enzymes involved in the metabolism of drugs and hormones, the bioactivation of carcinogens, and the detoxification of xenobiotics. Knowledge of the structural and mechanistic basis of substrate specificity and activity i ... >> More

  The human cytosolic sulfotransfases (hSULTs) comprise a family of 12 phase II enzymes involved in the metabolism of drugs and hormones, the bioactivation of carcinogens, and the detoxification of xenobiotics. Knowledge of the structural and mechanistic basis of substrate specificity and activity is crucial for understanding steroid and hormone metabolism, drug sensitivity, pharmacogenomics, and response to environmental toxins. We have determined the crystal structures of five hSULTs for which structural information was lacking, and screened nine of the 12 hSULTs for binding and activity toward a panel of potential substrates and inhibitors, revealing unique "chemical fingerprints" for each protein. The family-wide analysis of the screening and structural data provides a comprehensive, high-level view of the determinants of substrate binding, the mechanisms of inhibition by substrates and environmental toxins, and the functions of the orphan family members SULT1C3 and SULT4A1. Evidence is provided for structural "priming" of the enzyme active site by cofactor binding, which influences the spectrum of small molecules that can bind to each enzyme. The data help explain substrate promiscuity in this family and, at the same time, reveal new similarities between hSULT family members that were previously unrecognized by sequence or structure comparison alone. << Less

  PLoS Biol. 5:E97-E97(2007) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.