Inhibition of recombinant human BACE2 extracellular domain expressed in baculovirus using Q-C(HS03)-lle-Asp-Leu-Ala-Val-Leu-Asp-HN-CH2-CH2-Mca as substrate incubated for 1 hr measured every 1 min for 15 mins by fluorescence assay
Inhibition of recombinant human BACE1 extracellular domain expressed in baculovirus using Q-C(HS03)-lle-Asp-Leu-Ala-Val-Leu-Asp-HN-CH2-CH2-Mca as substrate incubated for 1 hr measured every 1 min for 15 mins by fluorescence assay
Inhibition Assay: Recombinant BACE-1 (extracellular domain, expressed in baculovirus and purified using standard methods) at 0.1 to 1 nM concentrations is incubated with the test compound at various concentrations for 1 hour at room temperature in 100 mM acetate buffer, pH 4.5, containing 0.1% CHAPS. Activity was measured using a final concentration of 3 μM of the fluorescence-quenched substrate Q-C(HSO3)-Ile-Asp-Leu-Ala-Val-Leu-Asp-HN-CH2-CH2-Mca, where Q=2-nitro-5-amino benzoic acid and Mca=7-methoxy-4-coumarinyl acetic acid. Catalytic turnover was monitored in a Spectramax Gemini fluorescence plate reader (Molecular Devices) in black 96-well microplates using excitation/emission wavelength of 325 nm and 400 nm, respectively. Fluorescence increase was followed for 15 min, in 1 minute's intervals. The fluorescence/time slopes were calculated from duplicate wells and from wells without inhibitor and the IC50 values were calculated using a logistic 4-parameter model.
Inhibition Assay: Recombinant BACE-2 (extracellular domain, expressed in baculovirus and purified using standard methods) at 0.1 to 1 nM concentrations is incubated with the test compound at various concentrations for 1 hour at room temperature in 100 mM acetate buffer, pH 4.5, containing 0.1% CHAPS. Activity was measured using a final concentration of 3 μM of the fluorescence-quenched substrate Q-C(HSO3)-Ile-Asp-Leu-Ala-Val-Leu-Asp-HN-CH2-CH2-Mca, where Q=2-nitro-5-amino benzoic acid and Mca=7-methoxy-4-coumarinyl acetic acid. Catalytic turnover was monitored in a Spectramax Gemini fluorescence plate reader (Molecular Devices) in black 96-well microplates using excitation/emission wavelength of 325 nm and 400 nm, respectively. Fluorescence increase was followed for 15 min, in 1 minute's intervals. The fluorescence/time slopes were calculated from duplicate wells and from wells without inhibitor and the IC50 values were calculated using a logistic 4-parameter model.
Inhibition Assay: Chinese hamster ovary cells are transfected with the human gene for amyloid precursor protein. The cells are plated at a density of 8000 cells/well into 96-well microtiter plates and cultivated for 24 hours in DMEM cell culture medium containing 10% FCS. The test compound is added to the cells at various concentrations, and the cells are cultivated for 24 hours in the presence of the test compound. The supernatants are collected, and the concentration of amyloid peptide 1-40 is determined using state of the art immunoassay techniques, for example sandwich ELISA, homogenous time-resolved fluorescence (HTRF) immunoassay, or electro-chemiluminescence immunoassay. The potency of the compound is calculated from the percentage of inhibition of amyloid peptide release as a function of the test compound concentration.