title: A miniaturized 1536-well format gamma-secretase assay.
abstract: gamma-Secretase is an aspartyl protease that cleaves multiple substrates including the amyloid precursor protein (APP) and the Notch proteins. Abnormal proteolysis of APP is involved in the pathogenesis of Alzheimer's disease (AD) and overactive Notch signaling plays an oncogenic role in a variety of cancers. gamma-Secretase has emerged as a promising target for drug development in the treatment of AD and cancer. Assays with increased capacity for high-throughput screening would allow for quicker screening of chemical libraries and facilitate inhibitor development. We have developed a homogeneous time-resolved fluorescence (HTRF)-based assay that makes use of a novel biotinylated recombinant APP substrate and solubilized membrane preparation as the source of the gamma-secretase enzyme. The assay was miniaturized to a 1536-well format and validated in a pilot screen against a library of approximately 3,000 compounds. The overall assay performance was robust due to a calculated Z' factor of 0.74 and its demonstrated ability to identify known gamma-secretase inhibitors such as pepstatin A. This validated assay can readily be used for primary screening against large chemical libraries searching for novel inhibitors of gamma-secretase activity that may represent potential therapeutics for AD and a variety of neoplasms.
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Shelton
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: David
authors.initials: D
authors.lastname: Shum
authors.forename: Constantin
authors.initials: C
authors.lastname: Radu
authors.forename: Hakim
authors.initials: H
authors.lastname: Djaballah
authors.forename: Yue-Ming
authors.initials: YM
authors.lastname: Li
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000032:analysis* / Q000378:metabolism; D001331:Automation; D003362:Cost-Benefit Analysis; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation* / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D007202:Indicators and Reagents; D049449:Luminescence; D008904:Miniaturization
chemical_list: D007202:Indicators and Reagents; D053829:Amyloid Precursor Protein Secretases