A multimeric quinacrine conjugate as a potential inhibitor of Alzheimer's beta-amyloid fibril formation

Chembiochem. 2008 Apr 14;9(6):952-63. doi: 10.1002/cbic.200700602.

Abstract

Amyloid formation and accumulation of the amyloid beta-peptide (Abeta) in the brain is associated with Alzheimer's disease (AD) pathogenesis. Therefore, among the therapeutic approaches in development to fight the disease, the direct inhibition of the Abeta self-assembly process is currently widely investigated and is one of the most promising approaches. In this study we investigated the potential of a multimeric display of quinacrine derivatives, as compared to the monomer quinacrine, as a design principal for a novel class of inhibitors against Abeta fibril formation. The presented multimeric conjugate exhibits a cluster of four quinacrine derivatives on a rigid cyclopeptidic scaffold. Herein is reported the synthesis of the conjugate, together with the in vitro inhibitory evaluation of Abeta(1-40) fibrils using the thioflavin T fluorescence assay, and imaging with atomic force microscopy. Our data show that the multimeric compound inhibits Abeta(1-40) fibril formation with an IC(50) value of 20+/-10 microM, which contrasts with the nonactive monomeric analogue. This work suggests that assembling multiple copies of acridine moieties to a central scaffold, for multiple interactions, is a promising strategy for the engineering of inhibitors against Abeta fibril formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism*
  • Amyloid beta-Peptides / chemistry*
  • Amyloid beta-Peptides / metabolism*
  • Benzothiazoles
  • Dose-Response Relationship, Drug
  • Drug Design
  • Microscopy, Atomic Force
  • Protein Binding / drug effects
  • Quinacrine / analogs & derivatives
  • Quinacrine / chemical synthesis*
  • Quinacrine / chemistry
  • Quinacrine / pharmacology*
  • Spectrometry, Fluorescence
  • Thiazoles / chemistry

Substances

  • Amyloid beta-Peptides
  • Benzothiazoles
  • Thiazoles
  • thioflavin T
  • Quinacrine