Very sensitive and internally quenched fluorescent substrate for endothelin-converting enzyme-1 (ECE-1), a membrane-bound zinc metallopeptidase that is related to neprilysin in amino acid sequence. The kcat/Km value for the hydrolysis by ECE-1 was 1.9 x 10^7 M-1s-1 and 1.7 x 10^6 M-1s-1 for the hydrolysis by neprilysin. For MMP-2, MMP-9 the kcat/Km values are in the range of 10^4 M-1s-1 whereas for MMP-1 there was no hydrolysis observed. This peptide was hydrolyzed rapidly by stromelysin 1 (MMP-3) with kcat/Km=218000 M-1s-1 and very slowly by gelatinase B (MMP-9) (kcat/Km=10100 M-1s-1). There was no hydrolysis by MMP-1 and MMP-2 observed ; Tested Applications: HPLC; Molecular Weight: 1388.5 Da; Purity: Greater than 98 % purifiedConjugation: Unconjugated