AFM-IR spectra (top) of WT, A30P, and A53T α-syn aggregates formed in the lipid-free environment (PS-free), as well as in the presence of POPS, DOPS, DMPS, and DSPS with corresponding bar graphs (bottom) showing the amount of parallel β-sheet (gray), α-helix and random coil (yellow), β-turn (blue), and antiparallel β-sheet (light gray) in these aggregates. One-way ANOVA with Tukey’s honestly significant difference post hoc was performed to reveal statistical significance between all groups. ∗p ≤ 0.05, ∗∗p ≤ 0.01, ∗∗∗p ≤ 0.001, and ∗∗∗∗p ≤ 0.0001. For the ∗P, comparing with lipid-free environment in blue; comparing with WT in red; comparing with A30P in green. α-syn, α-synuclein; AFM, atomic force microscopy; DMPS, 1,2-dimyristoyl-sn-glycero-3-phospho-Lserine; DOPS, 1,2-dioleoyl-sn-glycero-3-phospho-L-serine; DSPS, 1,2-distearyl-sn-glycero-3-phospho-L-serine; NS, nonsignificant difference; POPS, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine; PS, phosphatidylserine.