α-Synuclein Interaction with Lipid Bilayer Discs.

Area of Science:

• Biochemistry
• Neuroscience
• Biophysics

Background:

• Alpha-synuclein (aSyn) is implicated in Parkinson's disease.
• aSyn self-assembles into amyloid fibrils and interacts with lipid membranes.
• Understanding aSyn-lipid interactions is crucial for synaptic function research.

Purpose of the Study:

• To investigate the interaction of alpha-synuclein with model lipid bilayer discs.
• To characterize the structural changes in lipid discs upon aSyn adsorption and desorption.

Main Methods:

• Cryogenic transmission electron microscopy (cryo-TEM).
• Small-angle neutron scattering (SANS).

Main Results:

• aSyn adsorption induces a significant shape transition in lipid bilayer discs.
• aSyn self-assembly into fibrils leads to desorption from the discs.
• Desorption follows an all-or-none mechanism, resulting in binary coexistence of disc shapes.
• Observed coexistence aligns with cooperative aSyn adsorption to anionic lipid bilayers.

Conclusions:

• aSyn adsorption and fibril formation dynamically alter lipid membrane structure.
• The all-or-none desorption mechanism highlights cooperative binding phenomena.
• This study provides insights into the interplay between aSyn, lipids, and disease-associated aggregation.