Gallic acid oxidation products alter the formation pathway of insulin amyloid fibrils.

Abstract

Amyloidogenic protein assembly into insoluble fibrillar aggregates is linked with several neurodegenerative disorders, such as Alzheimer's or Parkinson's disease, affecting millions of people worldwide. The search for a potential anti-amyloid drug has led to the discovery of hundreds of compounds, none of which have passed all clinical trials. Gallic acid has been shown to both modulate factors leading to the onset of neurodegenerative disorders, as well as directly inhibit amyloid formation. However, the conditions under which this effect is seen could lead to oxidation of this polyphenol, likely changing its properties. Here we examine the effect of gallic acid and its oxidised form on the aggregation of a model amyloidogenic protein-insulin at low pH conditions. We show a vastly higher inhibitory potential of the oxidised form, as well as an alteration in the aggregation pathway, leading to the formation of a specific fibril conformation.

• Authors: Andrius Sakalauskas, Mantas Ziaunys, Vytautas Smirnovas
• Journal: Scientific reports (Sci Rep) Vol. 10 Issue 1 Pg. 14466 (09 02 2020) ISSN: 2045-2322 [Electronic] England
• PMID: 32879381 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amyloid
• Amyloid beta-Peptides
• Amyloidogenic Proteins
• Insulin
• Gallic Acid

Topics

• Alzheimer Disease (genetics, metabolism, pathology)
• Amyloid (metabolism, ultrastructure)
• Amyloid beta-Peptides (metabolism)
• Amyloidogenic Proteins (metabolism, ultrastructure)
• Gallic Acid (metabolism)
• Humans
• Insulin (genetics, metabolism)
• Metabolic Networks and Pathways (genetics)
• Microscopy, Atomic Force
• Neurodegenerative Diseases (genetics, metabolism, pathology)
• Oxidation-Reduction
• Parkinson Disease (genetics, metabolism, pathology)
• Protein Aggregation, Pathological (genetics, metabolism)