A soluble protease identified from rat kidney degrades endothelin-1 but not proendothelin-1
| Autor: | Louis L. Martin, Arco Y. Jeng, Dominick DelGrande, Yilun Deng |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
Metabolic Clearance Rate medicine.medical_treatment Peptide Carboxypeptidases Kidney Biochemistry Rats Sprague-Dawley Endopeptidases medicine Animals Protein Precursors Molecular Biology chemistry.chemical_classification Protease biology Angiotensin II Endothelins Hydrolysis Proteolytic enzymes General Medicine Smooth muscle contraction Endothelin 1 Carboxypeptidase Rats Enzyme chemistry Solubility biology.protein Rabbits Atrial Natriuretic Factor |
| Zdroj: | Journal of biochemistry. 112(1) |
| ISSN: | 0021-924X |
| Popis: | Endothelin-1 (ET-1) is a potent peptidic vasoconstrictor. This peptide has been shown to be cleared rapidly by the kidney. The purpose of the present study was to assess the involvement of renal proteolytic enzymes in the clearance/degradation of ET-1. Incubation of ET-1 with the cytosolic fraction of rat kidney homogenate resulted in a decrease of contractile activity on rabbit aortic rings when compared to the untreated ET-1. This cytosolic fraction was chromatographed by anion-exchange and concanavalin A columns. The partially purified enzyme cleaved off the C-terminal tryptophan of ET-1 rapidly, resulting in a peptide which is three orders of magnitude weaker in potency than ET-1 in causing smooth muscle contraction. In contrast, proendothelin-1 was not degraded by this endothelin degradation enzyme (EDE). The effects of EDE on other vasoactive peptides were also examined. The C-terminal tyrosine of atrial natriuretic peptide was cleaved by EDE, but the biological activity of the resulting peptide was not significantly changed. Angiotensin II was not a substrate for EDE. The EDE was shown to be different from both carboxypeptidases A and B based on the HPLC analysis of the degradation products of ET-1 produced by these enzymes. In addition, these enzymes displayed different sensitivities toward a carboxypeptidase inhibitor from potato tuber. These results suggest that this previously unidentified enzyme inactivates ET-1 effectively and that it may play a role in modulating the levels of ET-1 in the kidney. |
| Databáze: | OpenAIRE |
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