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Amyloid-beta peptide (25-35) triggers a reorganization of lipid membranes driven by temperature changes

Oleksandr Ivankov1,2, Tatiana N Murugova3, Elena V Ermakova3

  • 1Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980, Dubna, Russia. ivankov@jinr.ru.

Scientific Reports
|November 10, 2021
PubMed

Insights

Alzheimer's disease (AD) research shows amyloid-beta (Aβ) peptide oligomers damage cell membranes. Temperature-induced lipid phase transitions cause Aβ peptides to alter membrane structure, forming new shapes and thinning the membrane.

Area of Science:

  • Biophysics
  • Neuroscience
  • Materials Science

Background:

  • Amyloid-beta (Aβ) peptide is implicated in Alzheimer's disease (AD).
  • Recent focus shifts to the role of small Aβ oligomers interacting with cell membranes, rather than extracellular fibrils.
  • Understanding Aβ interactions with lipid bilayers is crucial for AD pathogenesis.

Purpose of the Study:

  • To investigate the effect of temperature on the structural characteristics of phosphatidylcholine (PC) membranes containing Aβ25-35 peptide.
  • To elucidate the mechanism of Aβ-induced membrane damage and reorganization.

Main Methods:

  • Small Angle Neutron Scattering (SANS) was used to analyze membrane structure.
  • Zwitterionic phosphatidylcholine (PC) membranes with incorporated Aβ25-35 peptide were studied.
  • Experiments were conducted across different temperatures to observe lipid phase transitions.

Main Results:

  • Aβ25-35 induced spontaneous reformation of extruded unilamellar vesicles (EULVs) into discoidal bicelle-like structures (BLSs) and small unilamellar vesicles (SULVs).
  • These structural changes occurred specifically during lipid thermodynamic phase transitions and in the presence of the peptide.
  • Significant changes in membrane shape and thickness were observed, indicating peptide-triggered damage.

Conclusions:

  • Aβ25-35 peptides, not large fibrils, likely cause membrane damage by altering lipid self-organization.
  • The findings suggest a mechanism for Aβ-induced neurotoxicity at the membrane level.
  • Temperature-dependent lipid phase transitions can modulate Aβ peptide's interaction with and damage to cell membranes.

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