Burst Phase Analysis of the Aggregation Prone α-synuclein Amyloid Protein

Area of Science:

• Biochemistry
• Protein Dynamics
• Spectroscopy

Background:

• Protein refolding studies using stopped-flow spectrometry aim to identify folding intermediates.
• Contradictory findings exist regarding the validity of burst phase folding intermediates, with some suggesting solvent-dependent modifications.

Purpose of the Study:

• To investigate the burst phase dynamics of alpha-synuclein (Syn) amyloid protein using stopped-flow spectrometry.
• To explore solvent-dependent modifications and the formation of folding intermediates in Syn.

Main Methods:

• Stopped-flow spectrometry was employed to analyze the burst phase of alpha-synuclein.
• Control experiments were performed using N-alpha-acetyl-L-tyrosinamide (NAYA) and monomeric ubiquitin.

Main Results:

• Solvent-dependent modifications were observed for NAYA and ubiquitin.
• Alpha-synuclein exhibited aggregation at pH 7 and pH 2, but appeared monomeric at pH 3.
• At pH 3, Syn underwent hydrophobic collapse, forming a potential folded intermediate, followed by expansion due to solvent effects.

Conclusions:

• Both solvent-dependent modifications and the formation of a folded intermediate are likely occurring during the burst phase of alpha-synuclein.
• These findings contribute to understanding the complex dynamics of amyloid protein folding.