Figure 5

BACE inhibitor reduces pro-peptide cleavage of ASP-2 at pH 5 Pro-peptide cleavage of ASP-2 results in two peaks of 1094.4 and 1352.3 not present in the sample incubated with the BACE inhibitor (Mw = 1651 g/mol). These peaks are present when ASP-2 was incubated with EDTA. Samples of pure ASP-2 were prepared as described. Titration to ph 5 was carried out at 4°C and immediately EDTA (5 mM) or BACE inhibitor (20 μM, according to the protocol in Hussain et al. 2001) were added. Control ASP-2 at ph 5 contained no inhibitor. The peak of 1750 seen in the BACE inhibitor sample is also present in the inhibitor profile (not shown) and in agreement with its molecular weight is the inhibitor itself; additional larger bands are also present the inhibitor control sample. Following incubation samples were analysed by mass spectrometry as described in the methods.