Figure 1.

Detection of collagen I-driven β₂m amyloid formation. (A) ELISA probing dose-dependent adhesion of β₂m (10–80 μg/mL) to collagen I (10 μg/mL) or casein (10 μg/mL, used as a negative control), at pH 7.4. The average absorbance at 450 nm from triplicates within the same plate are reported with the standard deviation given as error bars. (B) ThT fluorescence curves of 85 μM β₂m (black), 85 μM β₂m + 3.4 mg/mL (8.5 μM) collagen I (blue), or 3.4 mg/mL collagen I alone (orange) over 650 h in 10 mM sodium phosphate buffer, pH 7.4, shaking at 600 rpm at 37 °C. Three representative curves are given for each condition. The inset shows a zoom-in of the baseline of the ThT fluorescence curves to highlight the lack of fluorescence enhancement for both β₂m (black) and collagen I (orange) alone. (C–E) Representative amplitude-modulated AFM images of (C) β₂m coincubated with collagen I fibrils, (D) collagen I fibrils alone, and (E) β₂m alone after incubation for 96 h at 37 °C with shaking.