EGCG redirects amyloidogenic polypeptides into unstructured, off-pathway oligomers

Nat Struct Mol Biol. 2008 Jun;15(6):558-66. doi: 10.1038/nsmb.1437. Epub 2008 May 30.

Abstract

The accumulation of beta-sheet-rich amyloid fibrils or aggregates is a complex, multistep process that is associated with cellular toxicity in a number of human protein misfolding disorders, including Parkinson's and Alzheimer's diseases. It involves the formation of various transient and intransient, on- and off-pathway aggregate species, whose structure, size and cellular toxicity are largely unclear. Here we demonstrate redirection of amyloid fibril formation through the action of a small molecule, resulting in off-pathway, highly stable oligomers. The polyphenol (-)-epigallocatechin gallate efficiently inhibits the fibrillogenesis of both alpha-synuclein and amyloid-beta by directly binding to the natively unfolded polypeptides and preventing their conversion into toxic, on-pathway aggregation intermediates. Instead of beta-sheet-rich amyloid, the formation of unstructured, nontoxic alpha-synuclein and amyloid-beta oligomers of a new type is promoted, suggesting a generic effect on aggregation pathways in neurodegenerative diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / chemistry
  • Amyloid / drug effects*
  • Amyloid Neuropathies / drug therapy
  • Amyloid Neuropathies / prevention & control*
  • Amyloid beta-Peptides / chemistry
  • Catechin / analogs & derivatives*
  • Catechin / chemistry
  • Catechin / pharmacology
  • Humans
  • Peptide Fragments / chemistry
  • Plaque, Amyloid / chemistry
  • Plaque, Amyloid / drug effects*
  • Protein Binding
  • alpha-Synuclein / chemistry

Substances

  • Amyloid
  • Amyloid beta-Peptides
  • Peptide Fragments
  • alpha-Synuclein
  • amyloid beta-protein (1-34)
  • Catechin
  • epigallocatechin gallate