Synthesis and biological evaluation of clicked curcumin and clicked KLVFFA conjugates as inhibitors of beta-amyloid fibril formation

Bioconjug Chem. 2009 Nov;20(11):2123-32. doi: 10.1021/bc900281b.

Abstract

Abnormal aggregation of beta-amyloid (Abeta) peptides into toxic aggregates has been identified as a key event in Alzheimer's disease (AD). Inhibition of this process has thus emerged as a major therapeutic track against AD. The present work describes the synthesis and in vitro study of a novel class of inhibitors. Two copies of Abeta-binding motifs (either curcumin or the KLVFFA peptide) are clicked via copper(I)-mediated azide-alkyne cycloaddition on a constrained cyclopeptide scaffold designed to interfere with Abeta aggregation. Our conjugates strongly inhibit amyloid fibril formation from Abeta(40) at low inhibitor to Abeta molar ratios (e.g., 0.02:1 in the case of the KLVFFA conjugate) at which Abeta-binding motifs alone are fully inactive (thioflavin T assays and atomic force microscopy observation). This work highlights the value of combining Abeta-recognition domains with a steric hindrance-inducing scaffold for preventing amyloid fibril formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / drug therapy
  • Alzheimer Disease / prevention & control
  • Amino Acid Sequence
  • Amyloid beta-Peptides / antagonists & inhibitors*
  • Amyloid beta-Peptides / chemistry
  • Curcumin / chemistry*
  • Drug Design
  • Humans
  • Peptide Fragments / chemistry*

Substances

  • Amyloid beta-Peptides
  • Peptide Fragments
  • amyloid beta-protein (16-20)
  • Curcumin