Membrane order and ionic strength modulation of the inhibition of the membrane-bound acetylcholinesterase by epigallocatechin‑3‑gallate

Biochim Biophys Acta Biomembr. 2019 Jan;1861(1):170-177. doi: 10.1016/j.bbamem.2018.08.002. Epub 2018 Aug 11.

Abstract

In the present work, we analyzed how external factors can modulate the efficiency of epigallocatechin‑3‑O‑gallate (EGCG) inhibition of a membrane-bound isoform of the acetylcholinesterase. Increasing the ionic strength but not the osmolarity of the bulk medium proved to be an important factor. In addition, we verified a clear correlation between the inhibitory activity with the order degree of the membranes by using cholesterol-partially depleted red blood cell ghosts. These two factors i.e. high salt concentration in the bulk medium and less viscous membranes, allow a deeper insertion of the EGCG into the lipid bilayer, thus leading to a greater inhibition of AChE. As a corollary, we propose that any treatment or process that leads to a slight decrease in cholesterol content in the membranes can efficiently enhance the inhibitory activity of EGCG, which can have important consequences in all the pathologies where the inhibition of AChE is recommended.

Keywords: Cholesterol; Ionic strength; Membrane interaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / metabolism*
  • Catechin / analogs & derivatives*
  • Catechin / chemistry
  • Cholesterol / chemistry
  • Cholinesterase Inhibitors / chemistry*
  • Erythrocyte Membrane / metabolism*
  • Humans
  • Ions
  • Kinetics
  • Lipid Bilayers / chemistry*
  • Osmolar Concentration*
  • Salts / chemistry
  • Solubility
  • Spectrometry, Fluorescence
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Cholinesterase Inhibitors
  • Ions
  • Lipid Bilayers
  • Salts
  • Catechin
  • Cholesterol
  • epigallocatechin gallate
  • Acetylcholinesterase