The purification and characterization of a prostacyclin dehydrogenase from rabbit kidney.
A highly purified NADP-linked 15-hydroxyprostaglandin (prostacyclin) dehydrogenase has been isolated from rabbit kidney. This enzyme has a molecular weight of 56,000-62,000 and is composed of two subunits which are presumably identical. It is not a flavoprotein. Fluorometric titrations with NADPH revealed that the cofactor was bound to the free enzyme with a dissociation constant of 0.04 microM. The results of kinetic studies were compatible with either a random mechanism or an ordered mechanism with NADP binding first. Although this enzyme oxidizes prostacyclin more rapidly than any other prostaglandin, it reduces 4-nitrobenzaldehyde, phenanthrenequinone, and menadione more rapidly than it oxidizes prostacyclin.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D006911:Hydroxyprostaglandin Dehydrogenases / Q000302:isolation & purification / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009249:NADP; D011485:Protein Binding; D011817:Rabbits; D013050:Spectrometry, Fluorescence
D000596:Amino Acids; D046911:Macromolecular Substances; D009249:NADP; D006911:Hydroxyprostaglandin Dehydrogenases