Comparative Analysis of the Relative Fragmentation Stabilities of Polymorphic Alpha-Synuclein Amyloid Fibrils

Area of Science:

• Biochemistry
• Neuroscience
• Structural Biology

Background:

• Amyloid fibril fragmentation is crucial for the spread of neurodegenerative diseases, including Parkinson's disease.
• The relative fragmentation stabilities of different amyloid fibril types and polymorphs are not well quantified.
• Understanding fibril fragmentation is key to comprehending amyloid propagation and disease phenotypes.

Purpose of the Study:

• To quantify the relative fragmentation stabilities of different alpha-synuclein fibril structures.
• To establish a method for rapid comparative assessment of fibril fragmentation stability.
• To investigate the influence of specific mutations (A30P, A53T) on fibril fragmentation.

Main Methods:

• Utilized controlled sonication as a mechanical perturbation for assessing fibril fragmentation.
• Applied the sonication method to compare fragmentation stabilities of wild-type (WT) alpha-synuclein fibrils and two familial mutant variants (A30P, A53T).
• Analyzed the length-dependent fragmentation behavior of different alpha-synuclein fibril polymorphs.

Main Results:

• Fibril fragmentation stabilities were found to be distinct and highly length-dependent across different alpha-synuclein polymorphs.
• Mutant A30P and A53T alpha-synuclein fibrils exhibited greater resistance to sonication-induced fragmentation compared to WT alpha-synuclein fibrils.
• Demonstrated significant differences in fragmentation resistance among morphologically distinct fibril structures.

Conclusions:

• Fragmentation stabilities of different amyloid fibril polymorphs are diverse.
• The developed sonication-based approach provides a rapid method for comparing fibril fragmentation stabilities.
• Findings suggest that fibril structure and specific mutations influence resistance to fragmentation, impacting disease progression.