Stereoselective carbonyl reductases from rat skin and leukocyte microsomes converting 12-ketoeicosatetraenoic acid to 12(S)-HETE.
Cell-free preparations from rat polymorphonuclear leukocytes and skin were found to catalyze the reduction of 12-keto-5,8,10,14-eicosatetraenoic acid (12-KETE) to 12-hydroxyeicosatetraenoic acid (12-HETE). The reductase activity was associated with the microsomal fraction and showed a marked preference for NADH over NADPH as reducing cofactor. Characterization of the reaction product by chiral phase HPLC of the methyl ester derivative indicated that 12-KETE reduction generated almost exclusively 12(S)-HETE. The results demonstrate that rat skin and leukocyte microsomes possess an NADH-dependent 12-KETE reductase activity that forms 12(S)-HETE as a major product. The identification of stereoselective 12-KETE reductases provides a basis for further defining the role these enzymes may play in the regulation of 12-KETE levels and in the protection against degradation of 12-KETE to the pro-inflammatory 12(R)-HETE by selectively generating 12-HETE of the S configuration.
Merck Frosst Centre for Therapeutic Research, Pointe Claire-Dorval, Québec, Canada.
J P
JP
Falgueyret
Y
Y
Leblanc
D
D
Riendeau
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism*; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D009504:Neutrophils / Q000201:enzymology*; D051381:Rats; D012867:Skin / Q000201:enzymology*; D013379:Substrate Specificity
C054994:12-keto-5,8,11,13-eicosatetraenoic acid; D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000429:Alcohol Oxidoreductases