Phosphoramidon-sensitive endothelin converting enzyme in cultured vascular smooth muscle cells converts big endothelin-3 to endothelin-3.
Incubation of big endothelin-3 (big ET-3, 1-41) with the membrane fraction obtained from cultured vascular smooth muscle cells (VSMCs) resulted in time-dependent increases in immunoreactive-ET (IR-ET), which were suppressed by phosphoramidon. Analysis of the incubation mixture by reverse-phase high performance liquid chromatography (RP-HPLC) confirmed that the IR-ET was due to the mature ET-3 (1-21). ET-1 (1-21) generated during incubation of big ET-1 (1-39) with the membrane fraction was markedly suppressed by the addition of big ET-3 into the incubation mixture. When the cultured VSMCs were incubated with big ET-3, a conversion to the mature ET-3 was observed. This ET-3 generation from exogenously applied big ET-3 was also suppressed by phosphoramidon. We conclude that the phosphoramidon-sensitive ET converting enzyme in VSMCs converts big ET-1 and big ET-3 to their mature form.
Tsukahara
Y
Y
Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Japan.
Matsumura
Y
Y
Kuninobu
K
K
Kojima
T
T
Takaoka
M
M
Morimoto
S
S
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D019334:Endothelin-3; D000072396:Endothelin-Converting Enzymes; D016232:Endothelins / Q000378:metabolism*; D006020:Glycopeptides / Q000494:pharmacology; D008666:Metalloendopeptidases; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology*; D011498:Protein Precursors / Q000378:metabolism*; D011863:Radioimmunoassay; D013552:Swine
D019334:Endothelin-3; D016232:Endothelins; D006020:Glycopeptides; D011498:Protein Precursors; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes; C008890:phosphoramidon