Fig. 3

The structural properties of polyQ helices are tract length dependent. a Residue-specific helicity obtained for peptides L₄Q₄ to L₄Q₂₀ before (molecular dynamics (MD)) and after reweighting (rwMD) the trajectories obtained by MD on the basis of the backbone chemical shifts. b Comparison of the difference between the experimental and back-calculated Cα and C′ chemical shifts with those back-calculated from the reweighted MD trajectories obtained for peptides L₄Q₄ to L₄Q₂₀. c Representative structures for peptides L₄Q₄ to L₄Q₂₀, defined as the frame of each trajectory with residue-specific helicity most similar to the ensemble-averaged counterpart. Residues are colored as a function of their average helicity (in the reweighted ensemble) and the Cα atoms of Gln residues are shown as spheres