Purification and properties of 4-hydroxybiphenyl UDP-glucuronyltransferase from bovine liver microsomes.
A UDP-glucuronyltransferase isoform glucuronizes phenolic xenobiotics such as 4-nitrophenol, and an isoform glucuronizing 4-hydroxybiphenyl has also been found in rat liver. We purified a UDP-glucuronyltransferase isoform glucuronizing 4-hydroxybiphenyl from bovine liver microsomes by solubilization with 0.7% sodium cholate followed by three column chromatographic separations using DEAE-Toyopearl 650S, UDP-hexanolamine Sepharose 4B, and hydroxyapatite. The purified bovine liver 4-hydroxybiphenyl UDP-glucuronyltransferase (named Bovine 4HBGT) had glucuronidation activities toward 4-hydroxybiphenyl and 4-methylumbelliferone but had little activity toward 4-nitrophenol and 1-naphthol. The apparent molecular mass of Bovine 4HBGT was 54,000 Da on SDS-PAGE, and this was decreased to 50,000 Da by digestion with endo-beta-N-acetylglucosaminidase H. These data suggest that Bovine 4HBGT consists of a 50,000 Da polypeptide and a high mannose type oligosaccharide chain(s) of about 4,000 Da. The NH2-terminal sequence of GT-3 was GKVLVWPVDFSXWINI. These properties of Bovine 4HBGT were very similar to those of rat UDP-glucuronyltransferase glucuronizing xenobiotics. However, the NH2-terminal sequence of Bovine 4HBGT had higher homology with that of rat liver 4-hydroxybiphenyl UDP-glucuronyltransferase than with that of rat liver 4-nitrophenol UDP-glucuronyltransferase.
Kanehara
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H
Department of Veterinary Biochemistry, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido.
Yokota
H
H
Sato
M
M
Yuasa
A
A
D000595:Amino Acid Sequence; D000818:Animals; D001713:Biphenyl Compounds / Q000378:metabolism; D002384:Catalysis; D002417:Cattle; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D014453:Glucuronosyltransferase / Q000302:isolation & purification* / Q000378:metabolism; D006923:Hymecromone / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009284:Naphthols / Q000378:metabolism; D009596:Nitrophenols / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D001713:Biphenyl Compounds; D009284:Naphthols; D009596:Nitrophenols; C029350:1-naphthol; D006923:Hymecromone; C019046:4-phenylphenol; D014453:Glucuronosyltransferase; C024836:4-nitrophenol