Figure 5.

H₂O₂ generation assay for Aβ40 in (a) random coiled state (5% TFE) and (b) stable helical state (40% TFE). In (a), instead of generating free radicals, Aβ40 shows to inhibit the generation of free radical. (▲) 30 μM Cu²⁺ alone and (●) titration of Aβ40 with 30 μM Cu²⁺. On the other hand, in stable helical structure (b), Aβ40 produces free radical with copper, in (▲) 30 μM Cu²⁺ alone, (■) Aβ40 alone, (●) titration of Aβ40 with 30 μM Cu²⁺, and (⋄) Aβ40 with 30 μM Cu²⁺ and 1 mM Catalase. All measurements were incubated at 37°C for 1 hour.