The TACE (tumor necrosis factor-α-converting enzyme), also called ADAM metallopeptidase domain 17 (ADAM17), is a 70-kDa enzyme that belongs to the ADAM protein family of disintegrins and metalloproteases. TACE is believed to be involved in the processing of tumor necrosis factor alpha (TNF-α) at the surface of the cell, and from within the intracellular membranes of the trans-Golgi network. This process, which is also known as "shedding", involves the cleavage and release of a soluble ectodomain from membrane-bound pro-proteins (such as pro-TNF-α), and is of known physiological importance. In ADAM17 Inhibitor Screening Assay Kit, TACE hydrolyzes the specific FRET substrate to release the quenched fluorescent group, which can be detected fluorometrically at Ex/Em = 318/449 nm. In the presence of the potent TACE inhibitor, the hydrolyzation of substrate will be impeded. The kit provides a rapid, simple, sensitive and reliable test suitable for high-throughput screening of TACE inhibitors and can be modified to check the relative TACE activity.