A model for gain of function in superoxide dismutase

Area of Science:

• Biochemistry
• Molecular Biology
• Neuroscience

Background:

• Misfolded superoxide dismutase [Cu-Zn] (SOD1) proteins exhibit prion-like propagation.
• Wild-type SOD1 (wtSOD1) can be converted by misfolded SOD1 aggregates.
• SOD1 misfolding is linked to neurodegenerative diseases.

Purpose of the Study:

• To investigate the prion-like mechanism of SOD1 misfolding propagation.
• To explore the role of the SOD1 electrostatic loop (ESL) in misfolding and activity.
• To determine if restricting ESL mobility affects SOD1 catalytic and peroxidase activities.

Main Methods:

• Investigated the role of transient SOD1 oligomers in ESL enervation.
• Examined the gain of interaction (GOI) leading to amyloid-like filament formation.
• Assessed the impact of restricted ESL mobility on SOD1 catalytic and peroxidase functions.

Main Results:

• Enervation of the SOD1 ESL by transient oligomers promotes GOI and amyloid-like filament formation.
• Freedom of ESL motion is crucial for SOD1's superoxide dismutase catalytic activity.
• Restricting ESL mobility compromises catalytic activity and enhances peroxidase activity.

Conclusions:

• SOD1 oligomer formation is implicated in both protein misfolding and oxidation.
• ESL mobility is a key factor in regulating SOD1's dual enzymatic functions.
• This study provides insights into the molecular mechanisms underlying SOD1-related pathologies.