Figure 3.

Amyloid formation of β2m at varying concentrations of Na₂SO₄, H₂SO₄, TCA, or formic acid under ultrasonication.A and C, maximum values of ThT fluorescence at a neutral pH (blue) and LS (red), and CD ellipticities at 220 nm (black) at varying concentrations of Na₂SO₄ (A) and H₂SO₄ (C) in the presence of 10 mM HCl. ThT fluorescence was measured under neutral pH conditions. Open symbols indicate the average values and small closed symbols indicate the observed data; when only one data point was available, they are overlapped. B and D, CD spectra obtained after amyloid formation at varying concentrations of Na₂SO₄ (B) and H₂SO₄ (D). The CD spectrum at 0 mM H₂SO₄ (D) was taken from that at 0 mM Na₂SO₄ (B). E and G, maximum values of ThT fluorescence at a neutral pH (blue) and LS (red), and CD ellipticities at 220 nm (black) at varying concentrations of TCA (E) and formic acid (G) in the presence of 10 mM HCl. F and H, CD spectra obtained after amyloid formation at varying concentrations of TCA (F) and formic acid (H). TCA has large absorption in the far-UV region. The regions including noise were removed from the CD spectra. I, maximum values of ThT fluorescence against the concentrations of salts or acids. The HCl concentration does not include the contribution of 10 mM HCl. Kinetics of amyloid formation at varying concentrations of Na₂SO₄, H₂SO₄, TCA, and formic acid were shown in Figure S7.