Hello, Hanae.

I guess your question is how can you detect your g-secretase is working in your cells. You should set an experiment that involves Notch receptor cloning and fusion with GFP, constructing pNotch-GFP plasmid using pEGFP-N1 vector to the C-terminus of Notch.

Transfect cells with the pNotch-GFP plasmids, divide into four dishes, and activate the Notch receptor by adding recombinant DLL (a soluble delta-like ligand) into 2 dishes (one with inhibitor and the other without inhibitor). The remaining two dishes contain no DLL (one with inhibitor and the other without inhibitor).

This experimental set will give you the answer. You should see the activated and processed NICD (Notch intracellular domain)-GFP in the nuclei of the transfected cells only in the dish containing DLL without inhibitor, whereas You should not see translocated NICD-GFP into the nuclei of the cells containing DLL with the inhibitor. The inhibitor blocked the g-secretase activity, leading to inner surfaces of the plasma membrane labeled with GFP.

Think about the GFP distributions in the rest of dishes.

Hope you find the answer.

Hello

i agree with Sang Ho Lee , and see this link

Article Therapeutic Potential of γ-Secretase Inhibitors and Modulators

Good Luck