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Updated: Mar 6, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
Published on: March 21, 2025
The role of histidines in amyloid β fibril assembly
Kristoffer Brännström1, Tohidul Islam1, Linda Sandblad2
1Department of Medical Biochemistry and Biophysics, Umeå University, Sweden.
Abstract:
Low pH has a strong stabilising effect on the fibrillar assembly of amyloid β, which is associated with Alzheimer's disease. The stabilising effect is already pronounced at pH 6.0, suggesting that protonation of histidines might mediate this effect. Through the systematic substitution of the three native histidines in Aβ for alanines, we have evaluated their role in fibril stability. Using surface plasmon resonance, we show that at neutral pH the fibrillar forms of all His-Ala variants are destabilised by a factor of 4-12 compared to wild-type Aβ. However, none of the His-Ala Aβ variants impair the stabilising effect of the fibril at low pH.
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