Development of potent reversible selective inhibitors of butyrylcholinesterase as fluorescent probes

J Enzyme Inhib Med Chem. 2020 Dec;35(1):498-505. doi: 10.1080/14756366.2019.1710502.


Brain butyrylcholinesterase (BChE) is an attractive target for drugs designed for the treatment of Alzheimer's disease (AD) in its advanced stages. It also potentially represents a biomarker for progression of this disease. Based on the crystal structure of previously described highly potent, reversible, and selective BChE inhibitors, we have developed the fluorescent probes that are selective towards human BChE. The most promising probes also maintain their inhibition of BChE in the low nanomolar range with high selectivity over acetylcholinesterase. Kinetic studies of probes reveal a reversible mixed inhibition mechanism, with binding of these fluorescent probes to both the free and acylated enzyme. Probes show environment-sensitive emission, and additionally, one of them also shows significant enhancement of fluorescence intensity upon binding to the active site of BChE. Finally, the crystal structures of probes in complex with human BChE are reported, which offer an excellent base for further development of this library of compounds.

Keywords: Butyrylcholinesterase; fluorescence; inhibitor; probe.

MeSH terms

  • Amides / chemical synthesis
  • Amides / chemistry
  • Amides / pharmacology*
  • Animals
  • Butyrylcholinesterase / isolation & purification
  • Butyrylcholinesterase / metabolism*
  • Cholinesterase Inhibitors / chemical synthesis
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / pharmacology*
  • Crystallography, X-Ray
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / pharmacology*
  • Humans
  • Mice
  • Models, Molecular
  • Molecular Structure


  • Amides
  • Cholinesterase Inhibitors
  • Fluorescent Dyes
  • Butyrylcholinesterase

Grants and funding

This work was supported by the Slovenian Research Agency under research core funding P1-0208, and Grants L1-8157 and NC-0009; the French Ministry of Armed Forces (DGA, SSA); the Agence Nationale de la Recherche (ANR) under Grant ANR-12-BS07-0008–01; the France Alzheimer Foundation under Grant FA-AAP-2013–65-101349. We are grateful to the ESRF for beam-time under long-term projects MX1788 and MX1992 (IBS BAG).