Bock K W, Josting D, Lilienblum W, Pfeil H
Eur J Biochem. 1979 Jul;98(1):19-26. doi: 10.1111/j.1432-1033.1979.tb13155.x.
Glucuronidation reactions catalysed by rat liver microsomal UDP-glucuronyltransferase are differentially inducible by 3-methylcholanthrene and phenobarbital. To elucidate the molecular basis of this functional heterogeneity the enzyme was purified from livers of rats pretreated with the inducing agents. Using cholate solubilization, chromatography on Bio-Gel A-1.5m and on DEAE-cellulose in the presence of the nonionic detergent Brij 58, two enzyme forms could be separated. Both forms were subsequently purified to apparent homogeneity by affinity chromatography on UDP-hexanolamine Sepharose 4B, 3-Methylcholanthrene-inducible enzyme activity towards 1-naphthol, 4-nitrophenol, 3-hydroxybenzo(a)pyrene and N-hydroxy-2-naphthylamine copurified with one enzyme form (enzyme 1). In contrast phenobarbital-inducible enzyme activity towards morphine, chloramphenicol and 4-hydroxybiphenyl was associated with the other enzyme fraction (enzyme 2). Sodium dodecylsulfate/polyacrylamide gels showed similar molecular weights of 54000 for enzyme 1 and 56000 for enzyme 2. The results suggest the presence of at least two forms of UDP-glucuronyltransferase in rat liver. Factors affecting enzyme activity in purified and membrane-bound states are discussed.
大鼠肝脏微粒体UDP - 葡萄糖醛酸基转移酶催化的葡萄糖醛酸化反应可被3 - 甲基胆蒽和苯巴比妥差异诱导。为阐明这种功能异质性的分子基础，从经诱导剂预处理的大鼠肝脏中纯化该酶。利用胆酸盐增溶、在非离子去污剂Brij 58存在下于Bio - Gel A - 1.5m和DEAE - 纤维素上进行层析，可分离出两种酶形式。随后通过在UDP - 己醇胺琼脂糖4B上进行亲和层析将两种形式均纯化至表观均一。对1 - 萘酚、4 - 硝基苯酚、3 - 羟基苯并(a)芘和N - 羟基 - 2 - 萘胺具有3 - 甲基胆蒽诱导酶活性的部分与一种酶形式（酶1）共纯化。相反，对吗啡、氯霉素和4 - 羟基联苯具有苯巴比妥诱导酶活性的部分与另一种酶组分（酶2）相关。十二烷基硫酸钠/聚丙烯酰胺凝胶显示酶1的分子量为54000，酶2的分子量为56000，二者相似。结果表明大鼠肝脏中至少存在两种形式的UDP - 葡萄糖醛酸基转移酶。文中讨论了影响纯化状态和膜结合状态下酶活性的因素。
