Concomitant secretion of big endothelin and its C-terminal fragment from human and bovine endothelial cells.
A specific radioimmunoassay (RIA) for the carboxyl-terminal fragment (CTF) of big porcine endothelin (pET), an intermediate form of pET, was established to characterize big ET-like and its CTF-like immunoreactivity (LI) secreted from cultured bovine and human endothelial cells (EC). The antibody used crossreacted equally with big pET(1-39) and its CTF(22-39), but not with pET(1-21). Serial dilution curves of the culture media from bovine and human EC were parallel to that of standard CTF. Reverse-phase HPLC coupled with RIAs for big ET and ET of the culture media from bovine and human EC revealed essentially the same elution profiles: two major CTF-LI components, one corresponding to big pET(1-39) and the other to its CTF(22-39), in addition to one major ET-LI component corresponding to pET(1-21). The amounts of CTF-LI were almost equal to that of ET-LI on a molar basis. These data suggest that big ET is processed by a putative ET converting enzyme to yield its CTF and the mature ET(1-21) in EC.
Emori
T
T
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Hirata
Y
Y
Ohta
K
K
Shichiri
M
M
Shimokado
K
K
Marumo
F
F
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D016232:Endothelins; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D010452:Peptide Biosynthesis; D010455:Peptides / Q000302:isolation & purification; D011863:Radioimmunoassay; D014662:Vasoconstrictor Agents / Q000096:biosynthesis* / Q000302:isolation & purification
D016232:Endothelins; D010455:Peptides; D014662:Vasoconstrictor Agents