Converts big endothelin-1 to endothelin-1. Also involved in the processing of various neuroendocrine peptides, including neurotensin, angiotensin I, substance P, proenkephalin-derived peptides, and prodynorphin-derived peptides (By similarity). May play a role in amyloid-beta processing (By similarity). Hydrolysis of the 21-Trp-|-Val-22 bond in big endothelin to form endothelin 1. Binds 1 zinc ion per subunit. Isoform ECE2-1 and isoform ECE2-2 are expressed in brain and adrenal gland. Belongs to the peptidase M13 family.