Macromolecular crowding enhances Tau_244–372 fibrillization.

<p>Filament formation of human Tau fragment Tau_244–372 in the absence and in the presence of Ficoll 70 (A) and dextran 70 (B) respectively, monitored by ThT fluorescence. The crowding agent concentrations were 0 (a), 50 g/l (b), 100 g/l (c), and 200 g/l (d), respectively. Filament formation of Tau_244–372 in the absence and in the presence of Ficoll 70 (C) and dextran 70 (D) respectively, monitored by turbidity. The crowding agent concentrations were 0 (open square), 50 g/l (solid circle), 100 g/l (solid triangle), and 200 g/l (inverted solid triangle), respectively. The empirical Hill equation was fitted to the data and the solid lines represented the best fit. The final concentration of human Tau fragment was 12 µM. E and F: filament formation of Tau_244–372 at different concentrations in absence (a, c, and d) and in the presence of 100 g/l PEG 2000 (b, e, and f), represented by ThT fluorescence intensity at plateau. The data with error bars are expressed as the mean ± S.D. (<i>n</i> = 3). The assays were carried out at 37°C.