CHF5074, a γ-secretase modulator, reduces Aβ42/40 secretion (IC50: 3.6/18.4 μM).
GSK-3β activity assay: IC50 of new synthesised compound IM-12 to GSK-3β is determined by a luminometric GSK-3β activity assay. Briefly, compounds are tested in different concentrations diluted in assay buffer containing final concentrations of: 4 mM MOPS pH 7.2; 0.4 mM EDTA; 1 mM EGTA; 2.5 mM β-glycerophosphate; 4 mM MgCl2; 40 μM BSA; 0.05 mM DTT. Four microlitres of diluted compounds are added to 25 μM pGS-2 peptide substrate, 20 ng recombinant GSK-3β and 1 μM ATP to a total assay volume of 40 μl. The enzymatic reaction is stopped after 30 min of incubation at 30 °C by adding 40 μl KinaseGlo. The luminometric signal is allowed to stabilise for 10 min and the measured with a Glomax? 96 Microplate Luminometer.