Comparison of the efficacy of BACE2 relative to other well-established AßDPs in vitro and in cultured cells. A, Degradation of Aß in vitro by equivalent nominal concentrations (5 nM) of recombinant BACE2, IDE, NEP and plasmin. Note that BACE2 degrades Aß at a faster rate than NEP and plasmin, but not IDE. B,C, Effects on Aß40 (A) and Aß42 (C) levels following cotransfection of CHO cells with APP together with equivalent quantities of cDNAs encoding BACE2, ECE1b and IDE. In good agreement with the results in vitro (A), BACE2 lowers the levels of both Aß species to an extent exceeding NEP and ECE1b, but comparable to IDE. Data are mean ± SEM of 4 replications, normalized to controls cotransfected with empty vector (Vo).