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. May play a role in amyloid-beta processing (By similarity). {ECO:0000250|UniProtKB:B2RQR8, ECO:0000269|PubMed:12560336}. This is the function of ECE2 (endothelin converting enzyme 2, Ensembl gene identifier ENSG00000145194).