Ratiometric assay of CARM1 activity using a FRET-based fluorescent probe

Bioorg Med Chem Lett. 2019 Nov 15;29(22):126728. doi: 10.1016/j.bmcl.2019.126728. Epub 2019 Oct 4.

Abstract

One of the regulatory mechanisms of epigenetic gene expression is the post-translational methylation of arginine residues, which is catalyzed by protein arginine methyltransferases (PRMTs). Abnormal expression of PRMT4/CARM1, one of the PRMTs, is associated with various diseases, including cancers. Here, we designed and synthesized a Förster resonance energy transfer (FRET)-based probe, FRC, which contains coumarin and fluorescein fluorophores at the N-terminus and C-terminus of a peptide containing an arginine residue within an appropriate amino acid sequence to serve as a substrate of CARM1; the two fluorophores act as a FRET donor and a FRET acceptor, respectively. Since trypsin specifically hydrolyzes the arginine residue, but not a monomethylarginine or dimethylarginine residue, CARM1 activity can be evaluated from the change of the coumarin/fluorescein fluorescence ratio of FRC in the presence of trypsin.

Keywords: Asymmetric dimethylarginine; CARM1; Enzyme assay; Epigenetics; Fluorescent probe.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arginine / genetics
  • Arginine / metabolism
  • Coumarins / chemistry
  • Fluorescein / chemistry
  • Fluorescence Resonance Energy Transfer*
  • Fluorescent Dyes / chemistry*
  • Humans
  • Molecular Structure
  • Protein Processing, Post-Translational
  • Protein-Arginine N-Methyltransferases / metabolism*

Substances

  • Coumarins
  • Fluorescent Dyes
  • Arginine
  • coumarin
  • Protein-Arginine N-Methyltransferases
  • coactivator-associated arginine methyltransferase 1
  • Fluorescein