Efficient hit-finding approaches for histone methyltransferases: the key parameters

J Biomol Screen. 2012 Jan;17(1):85-98. doi: 10.1177/1087057111422823. Epub 2011 Oct 11.

Abstract

For many novel epigenetics targets the chemical ligand space and structural information were limited until recently and are still largely unknown for some targets. Hit-finding campaigns are therefore dependent on large and chemically diverse libraries. In the specific case of the histone methyltransferase G9a, the authors have been able to apply an efficient process of intelligent selection of compounds for primary screening, rather than screening the full diverse deck of 900 000 compounds to identify hit compounds. A number of different virtual screening methods have been applied for the compound selection, and the results have been analyzed in the context of their individual success rates. For the primary screening of 2112 compounds, a FlashPlate assay format and full-length histone H3.1 substrate were employed. Validation of hit compounds was performed using the orthogonal fluorescence lifetime technology. Rated by purity and IC(50) value, 18 compounds (0.9% of compound screening deck) were finally considered validated primary G9a hits. The hit-finding approach has led to novel chemotypes being identified, which can facilitate hit-to-lead projects. This study demonstrates the power of virtual screening technologies for novel, therapeutically relevant epigenetics protein targets.

MeSH terms

  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical / methods*
  • Enzyme Inhibitors / pharmacology
  • Epigenesis, Genetic / drug effects
  • Fluorescence
  • High-Throughput Screening Assays / methods*
  • Histocompatibility Antigens
  • Histone Methyltransferases
  • Histone-Lysine N-Methyltransferase / antagonists & inhibitors*
  • Histones / metabolism
  • Inhibitory Concentration 50
  • Ligands
  • Radiometry / methods
  • Reproducibility of Results
  • Small Molecule Libraries

Substances

  • Enzyme Inhibitors
  • Histocompatibility Antigens
  • Histones
  • Ligands
  • Small Molecule Libraries
  • Histone Methyltransferases
  • EHMT2 protein, human
  • Histone-Lysine N-Methyltransferase