Endothelin converting enzymes (ECEs), similar to neprilysin (NEP), belong to the M13 family of zinc metallopeptidases. ECEs (ECE-1/ECE-2) are known as the rate-limiting enzymes in the formation of the vasoconstrictor peptide endothelin-1 (ET-1) from its precursor proendothelin-1. ECE-1 can also degrade amyloid fragments both in vitro and in vivo. Highly homologous and structurally comparable to ECE-1, ECE-2 was shown in homozygous knockout mice to have decreased Abeta degradation and significant elevated Abeta 1-40 and 1-42 in the brain. Some studies indicate that carriers of ECE1 and ECE-2 gene variants may have an increased risk of developing late-onset Alzheimer’s disease (AD). However, the roles of ECE-1 and ECE-2 in AD progression have yet to be fully elucidated.
The SensoLyte® 520 ECEs Activity Assay Kit can be used to detect enzyme activity in biological samples or in purified enzyme preparations. When active ECEs cleave the FRET substrate, it results in an increase of 5-FAM fluorescence, and is monitored at excitation/emission = 490 nm/520 nm. The long wavelength fluorescence of 5-FAM shows less interference from autofluorescence of components in biological samples and test compounds. This assay can detect as low as 15.6 ng/mL active ECE-1 and 62.5 ng/mL active ECE-2.