Establishment of the experimental procedure for prediction of conjugation capacity in mutant UGT1A1

PLoS One. 2019 Nov 15;14(11):e0225244. doi: 10.1371/journal.pone.0225244. eCollection 2019.

Abstract

UDP-glucuronosyltransferase 1A1 (UGT1A1) is an enzyme that is found in the endoplasmic reticulum membrane and can reportedly have a large number of amino acid substitutions that result in the reduction of glucuronidation capacity. For example, adverse drug reactions when patients receive CPT-11 (irinotecan) such as in cancer chemotherapy are caused by amino acid substitutions in UGT1A1. We previously found that the extent of the docking when the hydroxyl residue of bilirubin was oriented toward UDP-glucuronic acid correlated with in vitro conjugation capacity. In this study, we analyzed the conformation of mutant UGT1A1s by means of structural optimization with water and lipid bilayers instead of the optimization in vacuo that we used in our previous study. We then derived a mathematical model that can predict the conjugation capacities of mutant UGT1A1s by using results of substrate docking in silico and results of in vitro analysis of glucuronidation of acetaminophen and 17β-estradiol by UGT1A1s. This experimental procedure showed that the in silico conjugation capacities of other mutant UGT1A1s with bilirubin or SN-38 were similar to reported in vitro conjugation capacities. Our results suggest that this experimental procedure described herein can correctly predict the conjugation capacities of mutant UGT1A1s and any substrate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / chemistry
  • Algorithms
  • Estradiol / chemistry
  • Glucuronosyltransferase / chemistry*
  • Glucuronosyltransferase / genetics
  • Glucuronosyltransferase / metabolism
  • Humans
  • Models, Molecular
  • Models, Theoretical
  • Molecular Conformation
  • Mutant Proteins*
  • Protein Binding
  • Protein Processing, Post-Translational
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Mutant Proteins
  • Acetaminophen
  • Estradiol
  • UGT1A1 enzyme
  • Glucuronosyltransferase

Associated data

  • figshare/10.6084/m9.figshare.10252772.v1

Grants and funding

This research was partially supported by Grants-in-Aid from Japanese Ministry of Education, Culture, Sports, Science and Technology (https://www.jsps.go.jp/english/index.html) No. 18K07414 (to Y.T.), No. 19K12202 (to A.S.), and No. 19K07867 (to M.O.), and Grants-in-Aid from Hyogo Science and Technology Association (http://hyogosta.jp) No. 27004 (to Y.T.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.