Sodium Oligomannate Electrostatically Binds to Aβ and Blocks Its Aggregation.

Area of Science:

• Biochemistry
• Biophysics
• Neuroscience

Background:

• GV-971 (sodium oligomannate) is approved in China for Alzheimer's disease treatment.
• GV-971 has demonstrated inhibition of amyloid-beta (Aβ) fibril formation in vitro and in vivo.
• Understanding the precise molecular mechanisms of GV-971's action on Aβ aggregation is crucial.

Purpose of the Study:

• To elucidate the molecular mechanisms by which GV-971 modulates Aβ40 and Aβ42 aggregation.
• To investigate the role of electrostatic interactions and dynamics in the GV-971-Aβ binding.
• To provide a detailed biochemical and biophysical characterization of the Aβ40/Aβ42:GV-971 system.

Main Methods:

• Systematic biochemical and biophysical analysis of Aβ40/Aβ42:GV-971 systems.
• Integration of previously published data with new experimental results.
• Analysis of electrostatic interactions and conformational flexibility.

Main Results:

• Multisite electrostatic interactions between GV-971's carboxylic groups and Aβ's histidine residues are key to GV-971 binding.
• GV-971 binding likely protects Aβ from aggregation by disrupting histidine-mediated inter-Aβ electrostatic interactions.
• A minor role for dynamics alteration in GV-971's modulation of Aβ aggregation was observed.

Conclusions:

• GV-971's primary mechanism involves electrostatic interactions with Aβ histidines, preventing aggregation.
• The drug's effect on Aβ dynamics plays a secondary role in its anti-aggregation activity.
• These findings enhance the understanding of GV-971's therapeutic potential for Alzheimer's disease.