Fig. 4.

Effect of rh Bri2 BRICHOS on the nucleation mechanism of Aβ42. a Aβ42 in the absence (black) and presence of 0.9 µM Bri2 BRICHOS monomers (red), dimer (green) and oligomer (blue) exhibit a very similar dependence of the aggregation half time, τ _1/2, on the initial peptide monomer concentration, described by the γ-exponent. b A global fit analysis from the data set in a revealed a dominate effect in $k_{+}{k}_2$, related to secondary nucleation and fibril-end elongation, where the Bri2 BRICHOS dimer is the most efficient species. c Estimation of the elongation rates from highly pre-seeded aggregation kinetics. d Estimated effect on the individual rate constants k ₊ and k ₂ from b and c by the different Bri2 BRICHOS species. The data in a and c are presented as means ± standard deviations of 3–6 replicates of experiments that have been repeated at least five times with qualitatively similar results. The errors of the γ-exponent in a and errors presented in b refer to the fitting errors. The errors in d are derived from the errors presented in b and c