Fig. 1

L-isoAsp in Aβ^20–34 accelerates fiber formation and can seed native segment. a Sequence of human Aβ including known early-onset hereditary mutations and posttranslational modifications (pyrE pyroglutamate, P phosphorylation, NO nitration, Y:Y dityrosine crosslink, HexNAc glycosylation, MetO oxidation). b ZipperDB²² amyloid propensity profile for the human Aβ sequence with the Aβ^20–34 sequence highlighted in light blue. c 1.6 mM of Aβ^20–34, Aβ^{20–34, Asp23Asn}, and Aβ^{20–34, isoAsp23} peptide aggregation was monitored by turbidity at 340 nm. Each data point is shown as a round symbol, the solid line represents the mean value, and error bars represent SD of three replicates. Transmission electron micrographs of aggregates are shown at the top left of the graph, scale bars represent 0.5 μm in each image. d Aggregation of 3.2 mM Aβ^20–34 in 50 mM Tris, pH 7.5, 150 mM NaCl, and 1% dimethyl sulfoxide was monitored by turbidity at 340 nm alone (black lines) or with 10 µM pre-aggregated seeds of Aβ^20–34 (yellow), Aβ^{20–34, isoAsp23} (blue), and Aβ^{20–34, Asp23Asn} (red). Each line represents a replicate well. Transmission electron micrographs of aggregates are shown at the top left of the graph; scale bars shown at the lower left represent 0.5 μm in each image. Source data are provided as a Source Data file