Extended Data Fig. 1: Bottom-up MS analysis of recombinant MDK proteins and their effect on Aβ fibrillation.
From: Midkine attenuates amyloid-β fibril assembly and plaque formation
a, Protein sequences of MDK proteins expressed in mammalian 293 or E. coli cells. The N-terminal His-tag was cleaved after expression by TEV protease. b, Workflow of bottom-up LC-MS/MS analysis to characterize the positions of disulfide (S-S) bonds. Proteins were subjected to IAA alkylation, trypsin digestion and LC-MS/MS analysis. Crosslinked peptides containing single or double S-S bonds were identified. c, Relative peak intensities of top five crosslinked peptides (n = 3 replicates). Data are shown as mean ± SEM. d-e, Effect of 293- or E. coli-expressed MDK (10 µM) on Aβ40/42 (5 µM) fibrillation kinetics in ThT fluorescence assays. Results represent the average of 3 replicates. Full statistical information is in Source Data Statistics.
