Structural Basis for Dityrosine-Mediated Inhibition of α-Synuclein Fibrillization

Area of Science:

• Biochemistry
• Neuroscience
• Structural Biology

Background:

• Alpha-synuclein (α-Syn) aggregation into plaques is a hallmark of Parkinson's disease.
• Oxidative stress is known to affect α-Syn structure and aggregation, but the mechanisms are unclear.

Purpose of the Study:

• To investigate the chemical and physical effects of mild oxidation on monomeric α-Syn.
• To understand how oxidation influences α-Syn self-assembly and amyloid formation.

Main Methods:

• Biophysical techniques
• Small-angle X-ray scattering (SAXS)
• Native ion mobility mass spectrometry (IM-MS)

Main Results:

• Mild oxidation induces intramolecular dityrosine cross-linkages in α-Syn.
• Oxidation causes a significant compaction of the α-Syn monomer (by a factor of √2).
• Oxidation-induced compaction inhibits ordered self-assembly and amyloid formation via steric hindrance.

Conclusions:

• Mild oxidation plays a crucial role in preventing α-Syn amyloid formation.
• The findings provide insights into the protective mechanisms against Parkinson's disease pathology.