Figure 8

Anti-amyloidogenic property of E22ΔAβ peptides in mixtures of different Aβ peptide variants. (a and b) Co-aggregation of E22Δ Aβ42 with wild-type (wt) Aβ42 (a) or E22Δ Aβ40 with wild-type Aβ40 (b) leads to a significant extension of the lag phase and a delay of the growth phase in comparison with the aggregation of the respective Aβ peptide variants alone (see Figure 7) (total monomer concentrations for each peptide variant: 2.5 μM). In contrast, co-aggregation of 2.5 μM E22G (Arctic) Aβ42 with 2.5 μM wild-type Aβ42 (a) results in a similar aggregation curve as with 2.5 or 5 μM E22G Aβ42 alone (see Figure 7). Co-aggregation of E22G Aβ40 with wild-type Aβ40 (b) only slightly delays β-sheet formation in comparison with E22G Aβ40 alone. (c) Co-aggregation of E22Δ Aβ40 with E22Δ Aβ42 in a physiological 9:1 ratio (total monomer end concentration in solution: 2.5 μM) leads to a strong inhibition of E22Δ Aβ40 aggregation. Note the dramatic delay of the growth phase and remarkable loss of absolute thioflavin T fluorescence in comparison to E22Δ Aβ40 alone (Figure 7). In contrast, 9:1 mixtures of E22G Aβ40 and E22G Aβ42 result in an aggregation curve very similar to E22G Aβ40 alone. Average curves of three independent experiments are shown (±s.e.m.).