Native Mass Spectrometry Based Method for Studying the Interactions between Superoxide Dismutase 1 and Stilbenoids

Area of Science:

• Biochemistry
• Biophysics
• Neuroscience

Background:

• Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease linked to mutations in the copper, zinc-superoxide dismutase (SOD1) gene.
• Abnormal aggregation of SOD1 is a key pathological feature in SOD1-linked ALS.
• Stilbene-based polyphenols are being explored for their therapeutic potential in neurodegenerative diseases.

Purpose of the Study:

• To investigate the interactions between SOD1 and four stilbene-based polyphenols: resveratrol, oxyresveratrol, polydatin, and 2,3,4',5-tetrahydroxystilbene-2-O-β-d-glycoside (THSG).
• To evaluate the potential of these polyphenols as therapeutic agents for SOD1-linked ALS by assessing their binding affinity, effect on SOD1 conformation, and inhibition of protein aggregation.

Main Methods:

• Electrospray ionization mass spectrometry (ESI-MS) coupled with ion mobility (IM) spectrometry was employed to study SOD1-polyphenol complexes.
• Tandem mass spectrometry (MS/MS) was used to analyze the gas-phase stability of these complexes.
• Ion mobility-mass spectrometry (IM-MS) monitored protein unfolding to assess ligand-induced stability changes.
• Fluorescence assays were conducted to evaluate the inhibition of apoSOD1 aggregation by the polyphenols.

Main Results:

• Polydatin and THSG exhibited the strongest binding interactions with SOD1 in the gas phase.
• Both polydatin and THSG demonstrated a stabilizing effect on the SOD1 dimer conformation.
• Fluorescence assays confirmed the ability of the tested polyphenols to inhibit apoSOD1 aggregation.
• Polydatin showed the most potent inhibitory effect on SOD1 aggregation among the tested compounds.

Conclusions:

• Polydatin and THSG are promising candidates for further investigation as therapeutic agents for SOD1-linked ALS due to their strong binding and stabilizing effects on SOD1.
• The developed ESI-MS/IM-MS method provides an effective platform for studying SOD1-ligand interactions and screening potential drug candidates.
• Targeting SOD1 aggregation with specific polyphenols represents a viable therapeutic strategy for ALS.