Publications

• Enzymatic inactivation of leukotriene B4 by a novel enzyme found in the porcine kidney. Purification and properties of leukotriene B4 12-hydroxydehydrogenase.

  Yokomizo T., Izumi T., Takahashi T., Kasama T., Kobayashi Y., Sato F., Taketani Y., Shimizu T.

  Leukotriene B4 (LTB4) 12-hydroxydehydrogenase was purified to apparent homogeneity from the cytosol fraction of the porcine kidney. The N-terminal amino acid sequence analysis revealed that this enzyme is a novel protein with a molecular weight of 35,000. Although the enzyme is ubiquitously distri ... >> More

  Leukotriene B4 (LTB4) 12-hydroxydehydrogenase was purified to apparent homogeneity from the cytosol fraction of the porcine kidney. The N-terminal amino acid sequence analysis revealed that this enzyme is a novel protein with a molecular weight of 35,000. Although the enzyme is ubiquitously distributed in various tissues and leukocytes of porcine, the kidney and liver had the highest enzyme activities. In the presence of NADP+ as a cofactor, the enzyme catalyzes the conversion of LTB4 to 12-oxo-LTB4, the structure identified by gas chromatography/mass spectrometry. 12-Oxo-LTB4 was further converted by other enzymes to 10,11,14,15-tetrahydro-12-oxo-LTB4, which was determined by proton NMR and gas chromatography/mass spectrometry. 12-Oxo-LTB4 was 100-fold less potent than LTB4 in increasing intracellular calcium concentrations of human leukocytes. 6-trans-LTB4 and LTB4 proved to be the best substrates of the enzyme, whereas various types of monohydroxyeicosatetraenoic acids, 5(S),12(S)-dihydroxyeicosatetraenoic acid, prostaglandins, cortisol, or pregnenolone could not serve as a substrate. These results suggest that the enzyme acts specifically on the 12(R)-hydroxy group of leukotriene B4 and is involved in the metabolic inactivation of LTB4 in the porcine kidney. << Less

  J. Biol. Chem. 268:18128-18135(1993) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.

• cDNA cloning, expression, and mutagenesis study of leukotriene B4 12-hydroxydehydrogenase.

  Yokomizo T., Ogawa Y., Uozumi N., Kume K., Izumi T., Shimizu T.

  Leukotriene B4 12-hydroxydehydrogenase catalyzes the conversion of leukotriene B4 into its biologically less active metabolite, 12-oxo-leukotriene B4. This is an initial and key step of metabolic inactivation of leukotriene B4 in various tissues other than leukocytes. Here we report the cDNA cloni ... >> More

  Leukotriene B4 12-hydroxydehydrogenase catalyzes the conversion of leukotriene B4 into its biologically less active metabolite, 12-oxo-leukotriene B4. This is an initial and key step of metabolic inactivation of leukotriene B4 in various tissues other than leukocytes. Here we report the cDNA cloning for porcine and human enzymes from kidney cDNA libraries. A full-length cDNA of the porcine enzyme contains an open reading frame consisting of 987 base pairs, corresponding to 329 amino acids. The human enzyme showed a 97.1% homology with the porcine enzyme. Northern blotting of human tissues revealed its high expression in the kidney, liver, and intestine but not in leukocytes. The porcine enzyme was expressed as a glutathione S-transferase fusion protein in Escherichia coli, which exhibited similar characteristics with the native enzyme. Because the enzymes have a homology, in part, with NAD(P)(+)-dependent alcohol dehydrogenases, a site-directed mutagenesis study was carried out. We found that three glycines at 152, 155, and 166 have crucial roles in the enzyme activity, possibly by producing an NADP+ binding pocket. << Less

  J. Biol. Chem. 271:2844-2850(1996) [PubMed] [EuropePMC]

• Human prostaglandin reductase 1 (PGR1): Substrate specificity, inhibitor analysis and site-directed mutagenesis.

  Mesa J., Alsina C., Oppermann U., Pares X., Farres J., Porte S.

  Prostaglandins (PGs) are lipid compounds derived from arachidonic acid by the action of cyclooxygenases, acting locally as messenger molecules in a wide variety of physiological processes, such as inflammation, cell survival, apoptosis, smooth muscle contraction, adipocyte differentiation, vasodil ... >> More

  Prostaglandins (PGs) are lipid compounds derived from arachidonic acid by the action of cyclooxygenases, acting locally as messenger molecules in a wide variety of physiological processes, such as inflammation, cell survival, apoptosis, smooth muscle contraction, adipocyte differentiation, vasodilation and platelet aggregation inhibition. In the inactivating pathway of PGs, the first metabolic intermediates are 15-keto-PGs, which are further converted into 13,14-dihydro-15-keto-PGs by different enzymes having 15-keto-PG reductase activity. Three human PG reductases (PGR), zinc-independent members of the medium-chain dehydrogenase/reductase (MDR) superfamily, perform the first irreversible step of the degradation pathway. We have focused on the characterization of the recombinant human enzyme prostaglandin reductase 1 (PGR1), also known as leukotriene B4 dehydrogenase. Only a partial characterization of this enzyme, isolated from human placenta, had been previously reported. In the present work, we have developed a new HPLC-based method for the determination of the 15-keto-PG reductase activity. We have performed an extensive kinetic characterization of PGR1, which catalyzes the NADPH-dependent reduction of the α,β-double bond of aliphatic and aromatic aldehydes and ketones, and 15-keto-PGs. PGR1 also shows low activity in the oxidation of leukotriene B4. The best substrates in terms of kcat/Km were 15-keto-PGE2, trans-3-nonen-2-one and trans-2-decenal. Molecular docking simulations, based on the three-dimensional structure of the human enzyme (PDB ID 2Y05), and site-directed mutagenesis studies were performed to pinpoint important structural determinants, highlighting the role of Arg56 and Tyr245 in 15-keto-PG binding. Finally, inhibition analysis was done using non-steroidal anti-inflammatory drugs (NSAIDs) as potential inhibitors. << Less

  Chem. Biol. Interact. 234:105-113(2015) [PubMed] [EuropePMC]

  This publication is cited by 10 other entries.