Purification and properties of prostaglandin D synthetase from rat brain.
The prostaglandin D synthetase system was isolated from rat brain. Prostaglandin endoperoxide synthetase solubilized from a microsomal fraction catalyzed the conversion of arachidonic acid to prostaglandin H2 in the presence of heme and tryptophan. Prostaglandin D synthetase (prostaglandin endoperoxidase-D isomerase) catalyzing the isomerization of prostaglandin H2 to prostaglandin D2 was found predominantly in a cytosol fraction and was purified to apparent homogeneity with a specific activity of 1.7 mumol/min/mg of protein at 24 degrees C. The enzyme also acted upon prostaglandin G2 and produced a compound presumed to be 15-hydroperoxy-prostaglandin D2. Glutathione was not required for the enzyme reaction, but the enzyme was stabilized by thiol compounds including glutathione. The enzyme was inhibited by p-chloromercuribenzoic acid in a reversible manner. The purified enzyme was essentially free of the glutathione S-transferase activity which was found in the cytosol of brain.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002729:Chloromercuribenzoates / Q000494:pharmacology; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology; D008970:Molecular Weight; D011451:Prostaglandin-Endoperoxide Synthases / Q000302:isolation & purification / Q000378:metabolism*; D011457:Prostaglandins D; D011463:Prostaglandins H; D051381:Rats; D012710:Serum Albumin, Bovine
D002729:Chloromercuribenzoates; D011457:Prostaglandins D; D011463:Prostaglandins H; D012710:Serum Albumin, Bovine; D011451:Prostaglandin-Endoperoxide Synthases