Extended Data Fig. 3: Characterization of ubiquitin protein by MS and its lack of effect on Aβ40/42 fibrillation.
From: Midkine attenuates amyloid-β fibril assembly and plaque formation
a, Purified Ub protein on a stained SDS gel. b-c, Top-down mass spectrum and deconvoluted results of Ub protein showing different charge states. Similar results were obtained in two independent experiments. d, Bottom-up LC-MS/MS analysis of Ub, covering the full Ub sequence except two short tryptic peptides (in grey). e, ThT fluorescence assay measuring Aβ40 fibril formation at different Ub concentrations (n = 3 replicates, averaged data shown). f, CD spectroscopy of Aβ40 with or without Ub, with ellipticity reported in millidegrees (mdeg). g, Negative stain EM of Aβ40/Ub samples with a scale bar (100 nm). h, ThT fluorescence assay measuring Aβ42 fibril formation at different Ub concentrations (n = 3 replicates, averaged data shown). i. CD spectroscopy of Aβ42 with or without Ub. j, Negative stain EM of Aβ42/Ub samples with a scale bar (100 nm). Similar results were obtained in two independent experiments. Full statistical information is in Source Data Statistics.
