Figure 6.

Ensemble observables from simulations of Aβ40 (red) and Aβ42 (blue). (A–C) Probability densities for peptide radii of gyration (R_g), end-to-end distances (R_ee), and FRET efficiencies (E), showing nearly overlapping distributions and ensemble averages (shown as vertical lines and as text annotations) for both isoforms. The major difference is the low end-to-end distance probability shoulder observed only for Aβ42, denoted by a blue star in (B). (D) J couplings from simulation (dashed lines and circles), compared with those derived from experiment (solid thick lines and squares, data from (32)), showing good agreement, as demonstrated by the low values of 〈χ²〉, where the average is taken over all residues. To see this figure in color, go online.