Fig. 3.

β-Secretase-dependent cleavage of the APP A673T fragment. An APP751 fragment (633–685) fused with FLAG tag (APP633–686-FLAG) was incubated with β-secretase. The E50 antibody was used to visualize the equal amounts of Aβ33-FLAG that were produced by β-secretase from the WT of the APP633–686-FLAG substrate and its A673T mutant substrate. The reaction solution of the WT substrate was loaded onto a gel, as indicated by standard curve. Data are expressed as means ± SD of three independent experiments. An unpaired t-test detected no significant differences between substrates