Figure 9.

TEM of Aβ(1–40) incubated with Cu²⁺ and ascorbate. Redox cycling of Cu^2+/+ by ascorbate oxidizes Aβ(1–40) and inhibits fibre formation while promoting short curvy-linear protofibrils. Preformed Aβ(1–40) fibres are fragmented into curvy-linear protofibrils by Cu^2+/+ with ascorbate. (a) Aβ (10 µM) with Cu²⁺ (5 µM) and ascorbate (500 µM). (b) 10 µM Ab(1–40) fibres formed with 500 µM ascorbate, but no Cu²⁺ (c) Preformed Aβ(1–40) fibres subsequently incubated with 5 µM Cu²⁺ and 500 µM ascorbate. (d) Quantification of fibre length before and after the addition of Cu²⁺  + Ascorbate. Data is comprised of more than 300 fibres for each condition.