Endothelin-converting enzyme activity in human serum lipoprotein fraction.
Endothelin-1 (ET-1)-converting enzyme (ECE) activity in the human serum lipoprotein fraction was studied using a sensitive enzyme immunoassay and reverse-phase high performance liquid chromatography. The ECE activity of cleaving synthetic human big ET-1 into ET-1 by the serum lipoprotein fraction was about 14-times greater than that by whole serum, and the activity was closely associated with lipoprotein itself. The lipoprotein ECE activity, which was optimal at pH 7.0, was inhibited by EDTA, o-phenanthroline, phosphoramidon, thiorphan, phenylmethanesulfonyl fluoride and chymostatin, but not by cysteine or aspartic proteinase inhibitors, suggesting metalloproteinase- and chymotrypsin-like properties. These results suggest that the serum lipoprotein ECE may be involved in the processing of big ET-1 to ET-1 in the circulatory system.
Ohwaki
T
T
Pharmaceutical Research Center, Nisshin Flour Milling Co. Ltd., Saitama, Japan.
Sakai
H
H
Hirata
Y
Y
D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors / Q000097:blood* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D019332:Endothelin-1; D000072396:Endothelin-Converting Enzymes; D016232:Endothelins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008074:Lipoproteins / Q000097:blood*; D008666:Metalloendopeptidases; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000378:metabolism
D019332:Endothelin-1; D016232:Endothelins; D008074:Lipoproteins; D011498:Protein Precursors; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes