Howland R D
Biochem J. 1978 Sep 15;174(3):1007-9. doi: 10.1042/bj1741007.
The glucuronidation of o-aminophenol is unaffected by p-nitrophenyl gluronide when native microsomal fractions are the source of UDP-glucuronyltransferase. When microsomal fractions treated with Lubrol detergent are the source of the enzyme, however, p-nitrophenyl glucuronide exhibits competitive inhibition of o-aminophenol glucuronidation. In addition, the apparent K1 for p-nitrophenyl glucuronide is the same whether o-aminophenol or p-nitrophenol is the acceptor substrate. The data suggest that UDP-glucuronyltransferase has one binding site for the two phenols and that the absence of inhibition observed in native microsomal fractions is dependent on an intact microsomal membrane.
当天然微粒体部分作为尿苷二磷酸葡萄糖醛酸基转移酶的来源时，对氨基苯酚的葡萄糖醛酸化不受对硝基苯基葡萄糖醛酸的影响。然而，当用Lubrol去污剂处理的微粒体部分作为该酶的来源时，对硝基苯基葡萄糖醛酸对氨基苯酚的葡萄糖醛酸化表现出竞争性抑制作用。此外，无论对氨基苯酚还是对硝基苯酚作为受体底物，对硝基苯基葡萄糖醛酸的表观K1都是相同的。这些数据表明，尿苷二磷酸葡萄糖醛酸基转移酶对这两种酚类有一个结合位点，并且在天然微粒体部分中未观察到抑制作用取决于完整的微粒体膜。
