Conversion of big endothelin-1 to endothelin-1 by two types of metalloproteinases derived from porcine aortic endothelial cells.
Incubation of big endothelin-1 (big ET-1(1-39] with either the cytosolic or membrane fraction obtained from cultured endothelial cells, resulted in an increase in immunoreactive-endothelin (IR-ET), which was markedly inhibited by metal chelators. Phosphoramidon, a metalloproteinase inhibitor, specifically suppressed the membrane fraction-induced increase in IR-ET, whereas the increase in IR-ET observed with the cytosolic fraction was not influenced by phosphoramidon. Reverse-phase (RP)-HPLC of the incubation mixture of big ET-1 with the cytosolic or membrane fraction revealed one major IR-ET component corresponding to the elution position of synthetic ET-1(1-21). Simultaneously, immunoreactivities like the C-terminal fragment (CTF22-39) of big ET-1 were present, as deduced from the RP-HPLC coupled with the radioimmunoassay for CTF. Our results indicate the presence of two types of metalloproteinases, which convert big ET-1 to ET-1 via a single cleavage between Trp21 and Val22, in vascular endothelial cells.
Matsumura
Y
Y
Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Japan.
Ikegawa
R
R
Tsukahara
Y
Y
Takaoka
M
M
Morimoto
S
S
D000818:Animals; D001013:Aorta, Thoracic; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D004492:Edetic Acid / Q000494:pharmacology; D019332:Endothelin-1; D016232:Endothelins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000201:enzymology*; D006020:Glycopeptides / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010446:Peptide Fragments; D010618:Phenanthrolines / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D013552:Swine
D019332:Endothelin-1; D016232:Endothelins; D006020:Glycopeptides; D010446:Peptide Fragments; D010618:Phenanthrolines; D011498:Protein Precursors; D004492:Edetic Acid; D008666:Metalloendopeptidases; C008890:phosphoramidon; C025205:1,10-phenanthroline