FIGURE 6.
Effect of A2V mutation of Aβ1–40 on the kinetics of 4G8-binding oligomers and on pharyngeal pumping rate in C. elegans. a and b, synthetic Aβ1–40 WT (a) or A2V (b) (100 μm) were incubated at 37 °C, and samples were taken at different times (from 0 to 48 h), diluted to 3 μm in PBS, and injected over immobilized 4G8 for 2 min (bar), followed by 11 min of dissociation. The figure shows the sensorgrams (time course of the SPR signal expressed in resonance units, RU) (black lines) obtained in a representative experiment. Sensorgrams were fitted as described for Fig. 1 and supplemental Fig. S1, dissecting the experimental curve into its quickly and slowly dissociating components (koff: 8.0 ± 0.2 × 10−3 s−1 and 6.0 ± 1.6 × 10−4 s−1, respectively). c, time course of the slowly dissociating components. Each point is the mean ± S.E. of three independent experiments. d, worms were fed for 2 h Aβ1–40, WT, or A2V (50 μm), freshly prepared (t = 0) or preincubated at 37 °C for 8 h. Control worms were fed vehicle alone. The values are the means ± S.E. (n = 20 worms). **, p < 0.01 versus all the other groups (Bonferroni's test after one-way ANOVA).