Fluorescence polarization-based assays for detecting compounds binding to inactive c-Jun N-terminal kinase 3 and p38α mitogen-activated protein kinase

Anal Biochem. 2016 Jun 15:503:28-40. doi: 10.1016/j.ab.2016.02.018. Epub 2016 Mar 5.

Abstract

Two fluorescein-labeled pyridinylimidazoles were synthesized and evaluated as probes for the binding affinity determination of potential kinase inhibitors to the c-Jun N-terminal kinase 3 (JNK3) and p38α mitogen-activated protein kinase (MAPK). Fluorescence polarization (FP)-based competition binding assays were developed for both enzymes using 1-(3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthen]-5-yl)-3-(4-((4-(4-(4-fluorophenyl)-2-(methylthio)-1H-imidazol-5-yl)pyridin-2-yl)amino)phenyl)thiourea (5) as an FP probe (JNK3: Kd = 3.0 nM; p38α MAPK: Kd = 5.7 nM). The validation of the assays with known inhibitors of JNK3 and p38α MAPK revealed that both FP assays correlate very well with inhibition data received by the activity assays. This, in addition to the viability of both FP-based binding assays for the high-throughput screening procedure, makes the assays suitable as inexpensive prescreening protocols for JNK3 and p38α MAPK inhibitors.

Keywords: Binding assay; Fluorescence polarization; c-Jun N-terminal kinase 3; p38α MAP kinase.

MeSH terms

  • Binding Sites / drug effects
  • Dose-Response Relationship, Drug
  • Fluorescence Polarization*
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Humans
  • Imidazoles / chemical synthesis
  • Imidazoles / chemistry*
  • Mitogen-Activated Protein Kinase 10 / antagonists & inhibitors*
  • Mitogen-Activated Protein Kinase 10 / chemistry
  • Mitogen-Activated Protein Kinase 10 / metabolism
  • Mitogen-Activated Protein Kinase 14 / antagonists & inhibitors*
  • Mitogen-Activated Protein Kinase 14 / chemistry
  • Mitogen-Activated Protein Kinase 14 / metabolism
  • Molecular Structure
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology*
  • Structure-Activity Relationship

Substances

  • Fluorescent Dyes
  • Imidazoles
  • Protein Kinase Inhibitors
  • Mitogen-Activated Protein Kinase 10
  • Mitogen-Activated Protein Kinase 14