Development of an HTRF Assay for the Detection and Characterization of Inhibitors of Catechol-O-Methyltransferase

J Biomol Screen. 2016 Jun;21(5):490-5. doi: 10.1177/1087057115616793. Epub 2015 Nov 18.


Catechol-O-methyltransferase (COMT) plays an important role in the deactivation of catecholamine neurotransmitters and hormones. Inhibitors of COMT, such as tolcapone and entacapone, are used clinically in the treatment of Parkinson's disease. Discovery of novel inhibitors has been hampered by a lack of suitable assays for high-throughput screening (HTS). Although assays using esculetin have been developed, these are affected by fluorescence, a common property of catechol-type compounds. We have therefore evaluated a new homogenous time-resolved fluorescence (HTRF)-based assay from CisBio (Codolet, France), which measures the production of S-adenosyl-L-homocysteine (SAH). The assay has been run in both HTS and medium-throughput screening (MTS) modes. The assay was established using membranes expressing human membrane-bound COMT and was optimized for protein and time to give an acceptable signal window, good potency for tolcapone, and a high degree of translation between data in fluorescence ratio and data in terms of [SAH] produced. pIC50 values for the hits from the HTS mode were determined in the MTS mode. The assay also proved suitable for kinetic studies such as Km,app determination.

Keywords: COMT; HTRF; catechol-O-methyltransferase.

MeSH terms

  • Benzophenones / therapeutic use
  • Catechol O-Methyltransferase / chemistry*
  • Catechol O-Methyltransferase / drug effects
  • Catechol O-Methyltransferase Inhibitors / chemistry
  • Catechol O-Methyltransferase Inhibitors / isolation & purification*
  • Catechol O-Methyltransferase Inhibitors / therapeutic use
  • Catechols / therapeutic use
  • High-Throughput Screening Assays / methods*
  • Humans
  • Kinetics
  • Nitrophenols / therapeutic use
  • Parkinson Disease / drug therapy
  • S-Adenosylhomocysteine / chemistry
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / isolation & purification*
  • Small Molecule Libraries / therapeutic use
  • Tolcapone


  • Benzophenones
  • Catechol O-Methyltransferase Inhibitors
  • Catechols
  • Nitrophenols
  • Small Molecule Libraries
  • S-Adenosylhomocysteine
  • Tolcapone
  • Catechol O-Methyltransferase
  • catechol