SensoLyte 520 TACE (a -Secretase) Activity Assay Kit Fluorimetric, (1 kit) TACE (tumor necrosis factor-alpha converting enzyme), a -secretase, or ADAM17 is a member of the ADAM family of proteases that contain both disintegrin and metalloprotease (catalytic) domains. This enzyme is involved in sperm-egg binding and fusion, muscle cell fusion, neurogenesis, modulation of Notch receptor and ligand processing, and processing of the pro-inflammatory cytokine, TNFa . TACE is currently being explored as a target for anti-inflammatory drugs. This Kit uses a 5-FAM (fluorophore) and QXL 520 (quencher) labeled FRET peptide substrate for continuous measurement of enzyme activity. In the intact FRET peptide, the fluorescence of 5-FAM is quenched by QXL 520. Upon cleavage of the FRET peptide by the active enzyme, the fluorescence of 5-FAM is recovered, and can be continuously monitored at excitation/emission = 490 nm/520 nm.