Assay Method Information

Assay Name:  In Vitro Enzymatic BACE1 and BACE2 FRET (Fluorescence Resonance Energy Transfer) Assays
Description:  The cDNAs for both human recombinant BACE1 and 2 with C-terminal 6-His Tags were cloned into transient protein expression vectors, which were subsequently transfected into mammalian cell lines. These recombinant proteins were further purified using Ni-NTA affinity chromatography (Qiagen). The assay buffer used in these screens was 0.05 M acetate, pH 4.5, 8% DMSO final, 100 μM genapol (which is a nonionic detergent, below its Critical Micelle Concentration). The β-secretase enzyme (0.02 nM for BACE1 and 0.64 nM for BACE2), which was pre-incubated for one hour with the test compound, typically in about 1 uL of DMSO according to a serial dilution, was added thereto. The assay was effectively started by the addition of FRET substrate (50 nM) and the combination was incubated for one hour. The FRET assay was terminated by the addition of tris buffer, which raised the pH to neutrality, and the fluorescence was determined. The FRET substrate was a peptide with commercially available fluorophore and quencher, on opposite sides of the BACE cleavage site. The specific FRET substrate used in this assay was made by Amgen in-house. Commercially available FRET substrates, for example, the FRET substrate offered with the BACE1 FRET Assay Kit sold by ThermoFisher Scientific (Catalog Number P2985), may be used in this assay with the appropriate modifications, which are within the purview of the ability of a person with ordinary skill in the art. Proteolytic cleavage of the FRET substrate released quenching of fluorescence (excitation 488 nm and emission 590 nm).
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail