Amyloid β peptides aggregation in a mixed membrane bilayer: a molecular dynamics study

Area of Science:

• Biochemistry
• Neuroscience
• Computational Biology

Background:

• Alzheimer's disease is linked to amyloid beta (Aβ) peptide aggregation into neurotoxic oligomers.
• The self-assembly mechanism of Aβ peptides within lipid bilayers remains poorly understood.

Purpose of the Study:

• To investigate the self-assembly of full-length amyloid beta peptides in a mixed lipid bilayer using molecular dynamics simulations.
• To elucidate the role of lipid-aqueous interface and cholesterol in Aβ peptide aggregation.

Main Methods:

• 1000 ns molecular dynamics simulations.
• Studied three full-length amyloid beta peptides within a zwitterionic dipalmitoylphosphatidylcholine and cholesterol mixed lipid bilayer.

Main Results:

• Residues 1-27 of Aβ peptides preferentially interacted with the lipid-aqueous interface.
• Residues 28-42 showed an inclination to remain within the bilayer's hydrophobic core.
• Cholesterol's interaction with Aβ peptides was inversely correlated with peptide-peptide interactions, and initial stages of β-sheet formation were observed.

Conclusions:

• Simulations provide insights into the complex Aβ peptide oligomerization process within lipid bilayers.
• Cholesterol plays a significant role in modulating Aβ peptide aggregation dynamics.
• Further experimental and theoretical studies are needed for a complete understanding.