Abstract
The processing and metabolism of big endothelin-1 (big ET-1) and endothelin-1 (ET-1) by a membrane fraction from pig lung was examined. The principal activity in this membrane fraction hydrolyzing ET-1 was identified as endopeptidase-24.11 (EC 3.4.24.11) by inhibitory and immunological criteria. More than 90% of this endopeptidase-24.11 activity could be removed by immunoadsorption. ET-converting activity was partially purified from the solubilized membrane fraction by lectin chromatography on a Ricinus communis agglutinin-120-agarose column followed by immunodepletion of endopeptidase- 24.11. The production of the C-terminal fragment of big ET-1 could be detected in this partially purified preparation and was inhibited by phosphoramidon (10 μM) but not by thiorphan (10 μM). The fluorogenic substrate succinyl-Ile-Ile-Trp-7-amido-4-methylcoumarin was hydrolyzed by pig lung membranes, but this activity was insensitive to phosphoramidon, suggesting that neither endopeptidase-24.11 nor endothelin-converting enzyme hydrolyze this substrate. Purified endopeptidase-24.11 also failed to hydrolyze the fluorogenic peptide.
| Original language | English |
|---|---|
| Pages (from-to) | S94-S97 |
| Number of pages | 4 |
| Journal | Journal of Cardiovascular Pharmacology |
| Volume | 22 |
| Issue number | SUPPL. 8 |
| DOIs | |
| Publication status | Published - 1993 |
| Externally published | Yes |
| Event | 3rd International Conference on Endothelain - Houston, United States Duration: 15 Feb 1993 → 17 Feb 1993 Conference number: 3 |