Is antagonism of E/Z-guggulsterone at the farnesoid X receptor mediated by a noncanonical binding site? A molecular modeling study

J Med Chem. 2005 Nov 3;48(22):6948-55. doi: 10.1021/jm0505056.

Abstract

Guggulsterone 1, the active principle of guggulipid, has been used in ethnic medicine for thousands of years for its antinflammatory and antilipidemic activities. The activities of 1 are apparently mediated by its interaction with an array of nuclear receptors, including endocrine steroid receptors and metabolic lipid receptors. Although relatively weak, the activity at the metabolic farnesoid X receptor (FXR) is particularly intriguing, as 1 is, so far, the only antagonist known for this receptor, with a peculiar ability of gene selective modulation. We report here a systematic study aimed at identifying the potential binding pocket of 1 at FXR. Although 1 could be docked into the canonical binding site, we identified a novel, so far undescribed binding pocket, localized near the loop region between helix 1 and helix 2. This novel binding pocket may explain some of the peculiar characteristics of 1 when acting at FXR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Commiphora
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / chemistry*
  • Ligands
  • Models, Molecular*
  • Pregnenediones / chemistry*
  • Protein Conformation
  • Receptors, Cytoplasmic and Nuclear
  • Stereoisomerism
  • Transcription Factors / antagonists & inhibitors
  • Transcription Factors / chemistry*

Substances

  • DNA-Binding Proteins
  • Ligands
  • Pregnenediones
  • Receptors, Cytoplasmic and Nuclear
  • Transcription Factors
  • farnesoid X-activated receptor
  • pregna-4,17-diene-3,16-dione