Figure 2

BACE2 degrades Aß in vitro. A, Percent Aß remaining following incubation with different concentrations of recombinant BACE2 for various lengths of time. Data are mean ± SEM of 4 replicates, normalized to protease-free controls. B, Comparison the relative Aß-degrading ability of recombinant BACE2 vs. BACE1. Note that 24 h incubation with BACE1 was required to achieve approximately the same extent of degradation as effected by BACE2 in 10 min. Data are mean ± SEM of 3 replicates, normalized to protease-free controls. C, BACE2 activity is pH dependent. Percent Aß degradation catalyzed by equivalent amounts of BACE2 at different pH values. Data are mean ± SEM of 4 replicates. D, BACE2 does not degrade fibrillar Aß. Lack of effect of BACE2 (10 nM) on preformed Aß42 fibrils following incubation at 37°C for 5 d, as determined by thioflavin T fluorescence. Data are mean ± SEM of 3 replicates.