Purification and Properties of 4-Hydroxybiphenyl UDP-Glucuronyltransferase from Bovine Liver Microsomes

• Published in: Journal of biochemistry (Tokyo) 1992-11, Vol.112 (5), p.578-582
• Main Authors: Kanehara, Hiroyuki, Yokota, Hiroghi, Sato, Masahiko, Yuasa, Akira
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Biphenyl Compounds - metabolism; Catalysis; Cattle; Chromatography, Liquid; Electrophoresis, Polyacrylamide Gel; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Glucuronosyltransferase - isolation & purification; Glucuronosyltransferase - metabolism; Hymecromone - metabolism; Male; Microsomes, Liver - enzymology; Molecular Sequence Data; Naphthols - metabolism; Nitrophenols - metabolism; Sequence Homology, Amino Acid; Substrate Specificity; Transferases
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a123943

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 solobilization with 0.7% sodium cholate followed by three column chromatographic separations using DEAE-Toyopearl 650S, UDP-hexanol-amine 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-nitro-phenol 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-β-N-acetylgluco-saminidase 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-nitro-phenol UDP-glucuronyltransferase.