Figure 1.

Circular dichroism spectra of Aβ40 peptide with or without Cu²⁺ in (a) 5% TFE and (b) 40% TFE. The concentration for both Aβ40 and Cu²⁺ used in measurements was 10 μM. It can be seen that the conformation of Aβ40 in 5% TFE shows a dramatic change in the presence of Cu²⁺, while the conformation of Aβ40 in 40% TFE remains unchanged in the presence or absence of Cu²⁺.