Figure 6. Interactions between Aβ-o with a graphene quantum dot.

(A) Initial structure of the simulation systems. A preformed Aβ tetramer was placed near the GQD. (B) Time evolution of the β-sheet content. Aβ-o: a preformed Aβ tetramer. Coaggregation: four Aβ-m with the GQD. (C) Secondary structure propensities of Aβ after the simulations reached the steady state. (D) β-sheet propensity of each Aβ residue in the absence and presence of the GQD. (E) Intra- and inter-peptide contact frequency maps for Aβ peptides. (F) Changes of the contact frequency maps in the presence of GQD compared with the control. (G, H) Two-dimensional potential of mean force (PMF) with respect to the number of β-sheet residues and radius of gyration for Aβ-o (G) and Aβ-o+GQD (H). The basins of the PMFs were labeled with typical snapshots presented on the right. The GQD was represented by sticks and Aβ-o in cartoon with the N-termini indicated by spheres.