Fig. 4

Structures of Aβ40 filaments from leptomeninges extracted using a water-based method. a Cross-sections of Aβ40 filaments from case 1 perpendicular to the helical axis, with a projected thickness of approximately one rung. Percentages of filaments are shown on the top right. The resolutions of the cryo-EM maps are indicated on the bottom left. Filaments were made of one, two or three pairs of protofilaments. Scale bar, 1 nm. b Cryo-EM density maps (transparent grey) and atomic model (pink) of type 2 Aβ40 filaments with two pairs of protofilaments. c Superposition of the structures of type 2 Aβ40 filaments that were extracted using either sarkosyl (cyan) or an aqueous solution (pink)