Mca-RPPGFSAFK(Dnp)-OH, also known as Mca-(Ala7,Lys(Dnp)9)-bradykinin is a very sensitive fluorescent substrate for endothelin-converting enzyme-1 (ECE-1), the membrane-bound zinc metallopeptidase that is related to neprilysin. Mca-RPPGFSAFK(Dnp)-OH can also be used for assaying ACE1, ACE2, BACE, cathepsin A, cathepsin X/Z, ECE-1, ECE-2, MMP-2, MMP9, neprilysin, insulinase and thermolysin (TLN), although it is not a substrate for MMP1. Mca-RPPGFSAFK(Dnp)-OH substrate contains a highly fluorescent 7-methoxycoumarin (Mca) group that is efficiently quenched by resonance energy transfer to the 2,4-dinitrophenyl (Dnp) group.
