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Rapid Generation of Amyloid from Native Proteins In vitro
05:48

Rapid Generation of Amyloid from Native Proteins In vitro

Published on: December 5, 2013

Myoglobin forms amyloid fibrils by association of unfolded polypeptide segments

Marcus Fändrich1, Vincent Forge, Katrin Buder

  • 1Institut für Molekulare Biotechnologie, Beutenbergstrasse 11, D-07745 Jena, Germany. fandrich@imb-jena.de

Proceedings of the National Academy of Sciences of the United States of America
|December 11, 2003
PubMed

Insights

Amyloid fibril formation depends on unfolded protein segments, not pre-formed structures. Denaturation conditions favor fibril assembly by promoting disordered polypeptide chains.

Area of Science:

  • Biochemistry
  • Structural Biology
  • Protein Misfolding Diseases

Background:

  • Amyloid fibrils are associated with neurodegenerative diseases.
  • Protein structure and denaturation influence fibril formation.
  • The assembly mechanism of amyloid fibrils remains debated.

Purpose of the Study:

  • To investigate the role of protein structure in amyloid fibril formation.
  • To determine whether fibrils assemble from pre-formed beta-structures or unfolded segments.
  • To explore the influence of denaturation on fibril assembly using apomyoglobin.

Main Methods:

  • Utilized alpha-helical protein apomyoglobin as a model system.
  • Varied denaturation conditions to assess their impact on fibril assembly.
  • Monitored for the presence of monomeric beta-sheet intermediates during fibril formation.

Main Results:

  • Fibril assembly ease correlated with the extent of denaturation.
  • No monomeric beta-sheet intermediates were observed under fibril-forming conditions.
  • Apomyoglobin fibril formation was dependent on disordered segments.

Conclusions:

  • Amyloid fibril formation is favored by conditions that promote unfolded polypeptide segments.
  • The assembly process likely involves disordered segments rather than pre-formed beta-structures.
  • Understanding these mechanisms is crucial for targeting protein misfolding diseases.

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