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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

Amyloid formation modulates the biological activity of a bacterial protein

Sylvain Bieler1, Lisbell Estrada, Rosalba Lagos

  • 1Department of Neurology, University of Texas Medical Branch, Galveston, Texas 77555, USA.

The Journal of Biological Chemistry
|May 27, 2005
PubMed

Insights

Microcin E492, a bacterial peptide, forms amyloid-like fibrils in vitro and in vivo. This suggests protein aggregation into amyloid fibrils is an evolutionarily conserved property used by bacteria for physiological needs.

Area of Science:

  • Biochemistry
  • Microbiology
  • Structural Biology

Background:

  • Protein aggregation into amyloid fibrils is linked to neurodegenerative diseases like Alzheimer's and Parkinson's.
  • Microcin E492 is a peptide produced by Klebsiella pneumoniae that forms pores in bacterial membranes, exhibiting toxicity.

Purpose of the Study:

  • To investigate the in vitro and in vivo amyloid fibril formation of microcin E492.
  • To compare the properties of microcin E492 amyloid fibrils with those found in human diseases.
  • To explore the physiological role of amyloid formation in bacteria.

Main Methods:

  • In vitro assembly of microcin E492 into amyloid-like fibrils.
  • Characterization of fibril properties (structural, morphological, tinctorial, biochemical).
  • In vivo studies of microcin E492 aggregation and toxicity.

Main Results:

  • Microcin E492 self-assembles into amyloid-like fibrils in vitro with properties similar to disease-associated aggregates.
  • Amyloid formation of microcin E492 was also observed in vivo.
  • In vivo amyloid formation correlated with a loss of microcin E492's toxicity.

Conclusions:

  • Protein aggregation into amyloid fibrils is an evolutionarily conserved mechanism.
  • Bacteria can utilize amyloid formation for specific physiological functions, as exemplified by microcin E492.
  • The study provides insights into the dual nature of protein aggregation, relevant to both disease and bacterial physiology.

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