(a) Folded (F) to unfolded (U) conversion for the peptides in the presence of Vps4, color coded as in the Vps24 structural model shown in the inset. (b-d) Mass spectra of selected peptides from helices α1 (b), α2 (c), and α4 (d) of Vps24-2 monomers (left), filaments (middle), or filament plus Vps4 (right). Controls and time points are indicated. Arrows above the spectra indicate regions of the spectrum representing EX2 and EX1 behavior. (e-g) Peak-width analysis of the selected peptides at 5, 10, 20, 30, 40, 60 s and full deuteration (TD) for selected peptides from helices α1 (e), α2 (f), and α4 (g). Open circles, Vps24-2 monomers; filled squares, Vps24-2 filaments; triangles, Vps24-2 filaments plus Vps4. The grey bar denotes the 2 Da peak-width band for peptides undergoing EX2 kinetics 41. (h) SDS-PAGE gel and quantification bar chart of Vps4WT-mediated disassembly of Vps24-2 filaments as analyzed by sedimentation. Pellet (P) and supernatant (S) fractions were analyzed by SDS-PAGE. Error bars are the s. d. of three experiments. WT, wild-type.