Separation, purification and characterization of three isoenzymes of UDP-glucuronyltransferase from rat liver microsomes

Arch Biochem Biophys. 1983 Nov;227(1):248-58. doi: 10.1016/0003-9861(83)90368-5.


Three isoenzymes of UDP-glucuronyltransferase (UDPGT) have been separated and purified from liver microsomes of untreated female rats or female rats pretreated with 3-methylcholanthrene. The UDPGT isoenzymes were purified utilizing Chromatofocusing, column isoelectric focusing, and UDP-hexanolamine Sepharose 4B affinity chromatography. UDPGT activities could also be separated during UDP-hexanolamine affinity chromatography by elution with different UDPGA (UDP-glucuronic acid) concentrations. One isoenzyme exhibits a subunit molecular weight of 56,000 and is capable of conjugating p-nitrophenol, 1-naphthol, and 4-methylumbelliferone. This isoenzyme is inducible by 3-methylcholanthrene treatment and requires high UDPGA concentrations for elution from the UDP-hexanolamine affinity column in contrast to the other UDPGT isoenzymes. A second isoenzyme was purified and displayed a subunit molecular weight of 50,000. This isoenzyme was not induced by 3-methylcholanthrene and was active towards testosterone, the 17-OH position of beta-estradiol, p-nitrophenol, and 1-naphthol. A third isoenzyme was also purified and exhibited a subunit molecular weight of 52,000. This isoenzyme conjugated androsterone and etiocholanolone and was not induced by 3-methylcholanthrene treatment. This study reports the purification of two separate and distinct rat liver UDPGT isoenzymes capable of conjugating p-nitrophenol, only one of which is inducible by 3-methylcholanthrene treatment. Also, this is the first report of the purification of a UDPGT isoenzyme active towards the 3-OH position of androgens.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chemical Phenomena
  • Chemistry
  • Chromatography / methods
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Induction / drug effects
  • Female
  • Glucuronosyltransferase / isolation & purification*
  • Isoelectric Focusing
  • Isoenzymes / classification
  • Isoenzymes / isolation & purification*
  • Methylcholanthrene / pharmacology
  • Microsomes, Liver / enzymology*
  • Rats
  • Rats, Inbred Strains
  • Solubility
  • Substrate Specificity


  • Isoenzymes
  • Methylcholanthrene
  • Glucuronosyltransferase