A cytosolic endothelin converting activity in guinea-pig lung: purification of a novel metalloprotease.
A proteinous fraction that produces endothelin-1 (ET-1) from big ET-1 in guinea-pig lung cytosol is described. An active protein has been successfully purified to homogeneity by combinations of sequential column chromatographies. The purified enzyme was a metalloenzyme based upon its sensitivity to chelating agent, and a molecular mass of the enzyme was 38 kDa estimated by gel filtration and SDS-PAGE. Further investigations revealed that the enzyme activity was abolished by sulfhydryl modifier such as N-ethylmaleimide, but inhibited neither by phosphoramidon, by thiorphan nor by captopril. The enzyme actually produced ET-1 with the Km value of 14.5 microM for big ET-1. These results indicate that this enzyme seems to be a novel metalloprotease that converts big ET-1 to ET-1.
Shima
H
H
Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co. Ltd., Osaka, Japan.
Yamanouchi
M
M
Omori
K
K
Sugiura
M
M
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D016232:Endothelins / Q000378:metabolism*; D006168:Guinea Pigs; D008168:Lung / Q000378:metabolism*; D008297:Male; D008666:Metalloendopeptidases / Q000302:isolation & purification*
D016232:Endothelins; D008666:Metalloendopeptidases