Endothelin-converting enzymes (ECEs) hydrolyze a specific peptide bond of big endothelins to produce active endothelins, some of the most potent vasoconstrictors known. ECE-1 is a member of the M13 zinc metallopeptidase family. Other members of the M13 family include thermolysin, neprilysin, Kell , and ECE-2. M13 metallopeptidases can be distinguished from other metallopeptidases by their sensitivity to inhibition by phosphoramidon. ECE-1 is most highly expressed in the cardiovascular endothelium, but is also expressed in some endocrine tissues. ECE-1 is known to hydrolyze a variety of bioactive pepti des, including bradykinin, neurotensin, angiotensins, and Substance P, with a substrate specificity similar to that of neprilysin. ECE-1 displays pronounced pH dependence in its substrate specificity. The degradation of Substance P by ECE-1 in endosomes regulates beta-arrestin-dependent ERK-2 signaling to prevent cell death in some neuronal cells. Four isoforms of ECE-1 are present in humans and mice, all of which encode a Type II integral membrane protein. The four isoforms share a common extracellular catalytic domain, differing in their N-terminal cytoplasmic tail regions. The recombinant mouse ECE-1 transmembrane and cytoplasmic tail domains were replaced with a signal sequence, resulting in the secretion of the soluble catalytic ectodomain. Recombinant protein corresponding to Gln89-Trp769 of mouse ECE-1 with a N-terminal 6-His tag, expressed in CHO cells. UniProt Accession: Q4PZA2. SDS-PAGE: ~90-130kD, reducing conditions. Biological Activity: Measured by its ability to to cleave the fluorogenic peptide substrate, Mca-RPPGFSAFK(Dnp)-OH. The specific activity is > 2250pmoles/min/ug Storage and Stability: For long-term storage, aliquot and store at -70C. Aliquots are stable for 6 months at -70C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
