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

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

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

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 MichaelisMenten kinetics with apparent Km and Vmax values of 3.8μM and 130.8 pmol min-1 mg-1 protein, respectively. Sulfation kinetics of bile acids also demonstrated MichaelisMenten kinetics with a marked variation in apparent Km and Vmax 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 (CLint) 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.

Original languageEnglish (US)
Pages (from-to)184-194
Number of pages11
JournalXenobiotica
Volume40
Issue number3
DOIs
StatePublished - Mar 1 2010

Keywords

  • Bile acids
  • Dehydroepiandrosterone
  • Kinetics
  • SULT2A1
  • Sulfation

ASJC Scopus subject areas

  • Biochemistry
  • Toxicology
  • Pharmacology
  • Health, Toxicology and Mutagenesis

Fingerprint Dive into the research topics of 'Kinetic analysis of bile acid sulfation by stably expressed human sulfotransferase 2A1 (SULT2A1)'. Together they form a unique fingerprint.

  • Cite this