CDNA cloning and functional analysis of minipig uridine diphosphate-glucuronosyltransferase 1A1

Yuuka Miyake, Kei Mayumi, Hideto Jinno, Toshiko Tanaka-Kagawa, Shizuo Narimatsu, Nobumitsu Hanioka

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) plays important roles in the glucuronidation of various drugs and endogenous substances. Minipigs have been used as experimental animals in pharmacological and toxicological studies, because many of their physiological characteristics are similar to those of humans. In this study, the similarities and differences in enzymatic properties of UGT1A1 between humans and minipigs were precisely identified. Minipig UGT1A1 (mpUGT1A1) cDNA was firstly cloned by the rapid amplification of cDNA ends (RACE) method, and the corresponding protein as well as human UGT1A1 (hUGT1A1) enzyme was expressed in insect cells. Then the kinetics of estradiol at 3-hydroxy position (E-3OH) and 7-ethyl-10- hydroxycamptothecin (SN-38) glucuronidation by recombinant UGT1A1s as well as human and minipig liver microsomes were analyzed. The homology between mpUGT1A1 and hUGT1A1 at the amino acid level was 80.9%. E-3OH and SN-38 glucuronidation by recombinant hUGT1A1 and mpUGT1A1 showed allosteric sigmoidal kinetics. The CLmax value (29.1 μL/min/mg protein) for E-3OH glucuronidation of mpUGT1A1 was significantly higher (1.4-fold) than that of hUGT1A1, whereas the CLmax value (0.83 μL/min/mg protein) for SN-38 glucuronidation was significantly lower (27%) than that of hUGT1A1; however, the kinetic models and parameter levels for E-3OH and SN-38 glucuronidation by human and minipig liver microsomes did not parallel those in the respective species. These findings suggest that the enzymatic properties of UGT1A1 are considerably different between humans and minipigs. The information on species differences in UGT1A1 function gained in this study should help with in vivo extrapolation of xenobiotic metabolism and toxicity.

Original languageEnglish
Pages (from-to)452-461
Number of pages10
JournalBiological and Pharmaceutical Bulletin
Volume36
Issue number3
DOIs
Publication statusPublished - Mar 2013
Externally publishedYes

Keywords

  • 7-ethyl-10-hydroxycamptothecin
  • Estradiol at 3-hydroxy position
  • Minipig
  • UGT1A1
  • Uridine diphosphate-glucuronosyltransferase (UGT)

ASJC Scopus subject areas

  • Pharmacology
  • Pharmaceutical Science

Fingerprint Dive into the research topics of 'CDNA cloning and functional analysis of minipig uridine diphosphate-glucuronosyltransferase 1A1'. Together they form a unique fingerprint.

Cite this