Converts big endothelin-1 to endothelin-1.
Subcellular locations: Cell membrane
All isoforms are expressed in umbilical vein endothelial cells, polynuclear neutrophils, fibroblasts, atrium cardiomyocytes and ventricles. Isoforms A, B and C are also expressed in placenta, lung, heart, adrenal gland and phaeochromocytoma; isoforms A and C in liver, testis and small intestine; isoform B, C and D in endothelial cells and umbilical vein smooth muscle cells; isoforms C and D in saphenous vein cells, and isoform C in kidney.