Enzyme substrates based on FRET (fluorescence resonance energy transfer) are extremely sensitive and reproducible tools used in a variety of applications. They are particularly used as protease substrates in high-throughput inhibitor screening and drug discovery.

A fluorescent donor and an acceptor (quencher) are attached to either end of the peptide sequence containing the cleavage site. When energy transfer occurs in the intact molecule, the acceptor molecule quenches the donor molecule fluorescence. When cleavage of the peptide by the protease occurs, the quencher and fluorophore are separated which leads to an increased fluorescence (refer to the image).

We have catalog FRET substrates and provide custom service for the synthesis of FRET substrate peptides.