Purity >95%. Gamma-Secretase is a multi-subunit aspartyl protease that cleaves amyloid precursor protein (APP) and many other type 1 transmembrane proteins, including Notch, E-cadherin, and ErbB4. The proteolysis of APP by secretases produces beta amyloid (ABeta), a 39- to 42-amino acid peptide which forms the amyloid plaques that are characteristic of Alzheimer's disease. DAPT is an inhibitor of Gamma-secretase, blocking the production of total ABeta in human primary neuronal cultures with an IC50 value of 115 nM and ABeta42 with an IC50 value of 200 nM. DAPT is also effective in vivo, reducing brain levels of ABeta when given orally to mice that are transgenic for human APPV717F or to rats. Through its effects on Gamma-secretase, DAPT indirectly inhibits Notch, affecting cell signaling and cell differentiation.