Figure 2.

Light-induced suppression of Aβ₄₂ self-assembly by MB. (a) CD spectra of Aβ₄₂ aggregates incubated under various conditions. Two characteristic peaks in the CD spectrum presenting the β-sheet structure disappeared in the MB (10 μM)-treated Aβ₄₂ (40 μM) under light illumination. (b) ThT fluorescence assay to measure the formation of amyloid fibrils. Significant decrease in ThT fluorescence indicates that the aggregation of Aβ₄₂ monomers was substantially suppressed. (c) Silver-stained native gel electrophoresis showing that the monomeric contents was highly increased in MB-treated Aβ₄₂ under light illumination. The arrow indicates a 4.5 kDa molecular mass that corresponds to the monomers of Aβ₄₂. (d–g) Representative AFM images of Aβ₄₂ incubated with or without MB under dark and light conditions. Only fragmented fibrils were observed in MB-treated Aβ₄₂ (see insets enlarged from panels).