Fig. 4. Positive charge accelerates nucleation of a minimal Aβ core.

a Effect of N-terminal (top) and C-terminal (bottom) truncations on nucleation (n = 3 biological replicates). Vertical error bars indicate 95% confidence interval of the mean NS. b AA sequences of N-terminal truncations that increase nucleation at FDR = 0.1. AA are colored by class. c Effect of adding a positively or negatively charged residue at the N or C-terminus of the Aβ core (AA 29–42). Nucleation quantified as percentage of colonies in medium lacking adenine vs. medium containing adenine (n > =4 biological replicates/variant). Boxplots represent median values and the lower and upper hinges correspond to the 25th and 75th percentiles, respectively. Whiskers extend from the hinge to the largest value no further than 1.5*interquartile range. One-way ANOVA with Dunnett’s multiple comparisons test (p_Aβ42 = 1.16e−3, p_K-core < 2.2e−16, p_R-core = 6.6e−16). *p < 0.05, **p < 0.01, *** p < 0.001. Source data are provided as a Source data file.