Figure 5. Coaggregation of Aβ peptides with ultrasmall MoS₂ quantum dots.

(A) Atomic structure of the ultrasmall MoS₂ QD used in our simulations. (B) Distribution of Aβ oligomer size in the absence and presence of ultrasmall MoS₂ QDs. (C) Secondary structure propensities of Aβ after the simulations reached the steady state. (D) Binding frequency of each Aβ residue with ultrasmall MoS₂ QDs. (E) Intra- and inter-peptide contact frequency maps for Aβ peptides. (F) Changes of the contact frequency maps for the system with Aβ:MoS₂=4:8 compared with the control one. (G, H) Two-dimensional potential of mean force (PMF) with respect of the number of inter-peptide hydrogen bond (H-bond) and radius of gyration (R_g) for Aβ peptides (G) and Aβ:MoS₂=4:8 (H). The basins of the PMF (i, ii and iii in panel G and 1, 2 and 3 in panel H) were labeled with the typical snapshots presented on the right. Ultrasmall MoS₂ QDs are shown as sticks and colored by elements. Aβ peptides are shown as cartoons and colored by chains with N-termini indicated by spheres and β-sheet structures highlighted in red.