Metabolism of endothelin-1 and big endothelin-1 by recombinant neutral endopeptidase EC.3.4.24.11.
1. Inhibitors of neutral endopeptidase EC.3.4.24.11 (NEP) have been shown to attenuate the hypertensive effect of big-endothelin-1 (BET-1) in rats. To determine whether NEP converts BET-1 to endothelin-1 (ET-1), the effect of a recombinant NEP (rNEP) on BET-1 and on ET-1 was assessed in vitro. 2. Incubation of [125I]-ET-1 with 1 microgram ml-1 of rNEP resulted in degradation of the peptide within minutes. Increase in the amount of rNEP to 10 micrograms ml-1 led to total cleavage of [125I]-ET-1 within seconds. 3. Phosphoramidon (10 microM) or SQ-28,603 (100 microM) totally suppressed the degradation of [125I]-ET-1 by rNEP. 4. The degradation of [125I]-BET-1 by either 1 or 10 micrograms ml-1 of rNEP was much slower than that of [125I]-ET-1. Again, both phosphoramidon and SQ 28,603 protected the peptide from degradation. 5. Intact [125I]-ET-1 was not observed when [125I]-BET-1 was incubated with rNEP. 6. These data show that neutral endopeptidase EC.3.4.24.11 is not an endothelin converting enzyme.
Abassi
Z A
ZA
Hypertension-Endocrine Branch, National Heart, Lung & Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Golomb
E
E
Bridenbaugh
R
R
Keiser
H R
HR
D000409:Alanine / Q000031:analogs & derivatives*; D002851:Chromatography, High Pressure Liquid; D018076:DNA, Complementary / Q000378:metabolism; D019332:Endothelin-1; D016232:Endothelins / Q000378:metabolism*; D006020:Glycopeptides / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D015260:Neprilysin / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D018076:DNA, Complementary; D019332:Endothelin-1; D016232:Endothelins; D006020:Glycopeptides; D007457:Iodine Radioisotopes; D011498:Protein Precursors; D011994:Recombinant Proteins; C065359:SQ 28603; D015260:Neprilysin; D000409:Alanine; C008890:phosphoramidon