The formation of bioactive amyloid species by prion proteins in vitro and in cells

Neurosci Lett. 2006 Oct 9;406(3):200-4. doi: 10.1016/j.neulet.2006.07.047. Epub 2006 Aug 17.


Amyloid proteins are a group of proteins that can polymerize into cross beta-sheeted amyloid species. We have found that enhancing cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) formazan exocytosis is a common property of bioactive amyloid species formed from all of the amyloid proteins tested to date. In this report, we show that the infectious amyloid species of the prion protein HET-s of the filamentous fungus Podospora anserina, like other amyloidogenic proteins, also enhances MTT formazan exocytosis. More strikingly, cellular MTT formazan exocytosis revealed the formation of bioactive amyloid species in prion-infected mouse N2a neuroblastoma cells. These findings suggest that cellular MTT formazan exocytosis can be useful for studying the roles of bioactive amyloid species in prion infectivity and prion-induced neurodegeneration.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Blotting, Western / methods
  • Cell Line, Tumor
  • Drug Interactions
  • Formazans
  • Fungal Proteins / pharmacology
  • In Vitro Techniques
  • Mice
  • Neuroblastoma
  • Peptide Fragments / pharmacology
  • Podospora
  • Prions / pharmacology*
  • Protein Conformation / drug effects
  • Rats
  • Tetrazolium Salts
  • Time Factors


  • Amyloid beta-Peptides
  • Formazans
  • Fungal Proteins
  • HET-S protein, Podospora anserina
  • Peptide Fragments
  • Prions
  • Tetrazolium Salts
  • MTT formazan