Figure 4.

Raman spectra of three Aβ_1–23 mutants before and after being incubated for 3 day for aggregation [172]. In the mutants, the Phe_CN residue was used to replace Tyr10 (Aβ_1–23M1), Phe19 (Aβ_1–23M2), and Phe20 (Aβ_1–23M3), respectively. The vertical dashed lines indicate Raman wavenumbers at 2229 and 2237 cm⁻¹, respectively. Reprinted with permission.