Kurita Ayumi, Miyauchi Yuu, Ikushiro Shin'ichi, Mackenzie Peter I, Yamada Hideyuki, Ishii Yuji
Laboratory of Molecular Life Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (A.K., Y.M., H.Y., Y.I.), Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, Imizu, Toyama, Japan (S.I.), and Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, SA, Australia (P.I.M.).
Laboratory of Molecular Life Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (A.K., Y.M., H.Y., Y.I.), Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, Imizu, Toyama, Japan (S.I.), and Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, SA, Australia (P.I.M.)
J Pharmacol Exp Ther. 2017 May;361(2):199-208. doi: 10.1124/jpet.117.240382. Epub 2017 Feb 22.
UDP-Glucuronosyltransferases (UGTs) are classified into three subfamilies in mice: Ugt1a, 2b, and 2a. In the subfamily, and appear to correspond to human and The mouse is an important animal for its use in investigations, but the substrate specificities of Ugt isoforms belonging to the 2b subfamily in mice remain largely unknown. To address this issue, we characterized the substrate specificity of all isoforms of the Ugt2b subfamily expressed in the mouse liver. The cDNAs of Ugt1a1, Ugt2a3, and all the Ugt2b isoforms expressed in the liver were reverse-transcribed from the total RNA of male FVB-mouse livers and then amplified. A baculovirus-Sf9 cell system for expressing each Ugt was established. Of all the Ugts examined, Ugt2b34, 2b36, and 2b37 exhibited the ability to glucuronidate morphine with Ugt2b36, the most active in this regard. Ugt1a1, but also Ugt2b34, 2b36, and 2b37 to a lesser extent, preferentially catalyzed the glucuronidation of 17-estradiol on the 3-hydroxyl group (E3G). With these isoforms, E3G formation by Ugt1a1 was efficient; however, Ugt2b5 exhibited a preference for the 17-hydroxyl group (E17G). Ugt2b1 and Ugt2a3 formed comparable levels of E3G and E17G. Ugt2b1 and 2b5 were the only isoforms involved in chloramphenicol glucuronidation. As Ugt2b36 is highly expressed in the liver, it is most likely that Ugt2b36 is a major morphine Ugt in mouse liver. Regarding E3G formation, Ugt1a1, like the human homolog, seems to play an important role in the liver.
尿苷二磷酸葡萄糖醛酸基转移酶（UGTs）在小鼠中分为三个亚家族：Ugt1a、2b和2a。在该亚家族中， 和 似乎分别对应于人类的 和 。小鼠是用于研究的重要动物，但其2b亚家族中Ugt同工型的底物特异性仍基本未知。为解决此问题，我们对小鼠肝脏中表达的Ugt2b亚家族所有同工型的底物特异性进行了表征。从雄性FVB小鼠肝脏的总RNA逆转录出Ugt1a1、Ugt2a3以及肝脏中表达的所有Ugt2b同工型的cDNA，然后进行扩增。建立了用于表达每种Ugt的杆状病毒-Sf9细胞系统。在所有检测的Ugt中，Ugt2b34、2b36和2b37表现出将吗啡葡萄糖醛酸化的能力，其中Ugt2b36在这方面活性最高。Ugt1a1以及在较小程度上Ugt2b34、2b36和2b37优先催化17-β-雌二醇在3-羟基上的葡萄糖醛酸化（E3G）。对于这些同工型，Ugt1a1形成E3G的效率很高；然而，Ugt2b5更倾向于17-羟基（E17G）。Ugt2b1和Ugt2a3形成的E3G和E17G水平相当。Ugt2b1和2b5是参与氯霉素葡萄糖醛酸化的仅有的同工型。由于Ugt2b36在肝脏中高度表达，Ugt2b36很可能是小鼠肝脏中主要的吗啡Ugt。关于E3G的形成，Ugt1a1与人类同源物一样，似乎在肝脏中起重要作用。
