III-31-C is a (hydroxyethyl)urea γ-secretase inhibitor th at binds to γ-secretase at the substrate docking site. DAPT, also a γ-secretase inhibitor binds to the substrate docking site as well. III-31-C is useful for the affinity isolation and characterization of the protease complex and for testing other ihhibitors th at affect the γ-secretase active site. The γ-secretase complex is composed of presenilin as a catalytic component and three integral membrane proteins, nicastrin, Aph-1 and Pen-2.
