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Palmer MA, Benatzy Y, Brüne B. Murine Alox8 versus the human ALOX15B ortholog: differences and similarities. Pflugers Arch 2024:10.1007/s00424-024-02961-w. [PMID: 38637408 DOI: 10.1007/s00424-024-02961-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/30/2024] [Accepted: 04/03/2024] [Indexed: 04/20/2024]
Abstract
Human arachidonate 15-lipoxygenase type B is a lipoxygenase that catalyzes the peroxidation of arachidonic acid at carbon-15. The corresponding murine ortholog however has 8-lipoxygenase activity. Both enzymes oxygenate polyunsaturated fatty acids in S-chirality with singular reaction specificity, although they generate a different product pattern. Furthermore, while both enzymes utilize both esterified fatty acids and fatty acid hydro(pero)xides as substrates, they differ with respect to the orientation of the fatty acid in their substrate-binding pocket. While ALOX15B accepts the fatty acid "tail-first," Alox8 oxygenates the free fatty acid with its "head-first." These differences in substrate orientation and thus in regio- and stereospecificity are thought to be determined by distinct amino acid residues. Towards their biological function, both enzymes share a commonality in regulating cholesterol homeostasis in macrophages, and Alox8 knockdown is associated with reduced atherosclerosis in mice. Additional roles have been linked to lung inflammation along with tumor suppressor activity. This review focuses on the current knowledge of the enzymatic activity of human ALOX15B and murine Alox8, along with their association with diseases.
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Affiliation(s)
- Megan A Palmer
- Institute of Biochemistry I, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
| | - Yvonne Benatzy
- Institute of Biochemistry I, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
| | - Bernhard Brüne
- Institute of Biochemistry I, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
- Frankfurt Cancer Institute, Goethe University Frankfurt, Frankfurt, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt, Frankfurt, Germany
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2
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An JU, Kim SE, Oh DK. Molecular insights into lipoxygenases for biocatalytic synthesis of diverse lipid mediators. Prog Lipid Res 2021; 83:101110. [PMID: 34144023 DOI: 10.1016/j.plipres.2021.101110] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 12/31/2022]
Abstract
Oxylipins derived mainly from C20- and C22-polyunsaturated fatty acids (PUFAs), termed lipid mediators (LMs), are essential signalling messengers involved in human physiological responses associated with homeostasis and healing process for infection and inflammation. Some LMs involved in the resolution of inflammation and infection are termed specialized pro-resolving mediators (SPMs), which are generated by human M2 macrophages or polymorphonuclear leukocytes and have the potential to protect and treat hosts from bacterial and viral infections by phagocytosis activation. Lipoxygenases (LOXs) biosynthesize regio- and stereoselective LMs. Thus, understanding the regio- and stereoselectivities of LOXs for PUFAs at a molecular level is important for the biocatalytic synthesis of diverse LMs. Here, we elucidate the catalytic mechanisms and discuss regio- and stereoselectivities and their changes of LOXs determined by insertion direction and position of the substrate and oxygen at a molecular level for the biosynthesis of diverse human LMs. Recently, the biocatalytic synthesis of PUFAs to human LMs or analogues has been conducted using microbial LOXs. Such microbial LOXs involved in the biosynthesis of LMs are expected to exert significantly higher activity and stability than human LOXs. Diverse regio- and stereoselective LOXs can be obtained from microorganisms, which represent a wealth of genomic sources. We reconstruct the biosynthetic pathways of LOX-catalyzed LMs in humans and other organisms. Furthermore, we suggest the effective methods of biocatalytic synthesis of diverse human LMs from PUFAs or glucose by using microbial LOXs, increasing the stability and activity of LOXs, combining the reactions of LOXs, and constructing metabolic pathways.
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Affiliation(s)
- Jung-Ung An
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea; Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Seong-Eun Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea
| | - Deok-Kun Oh
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea.
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3
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Kim TH, Lee J, Kim SE, Oh DK. Biocatalytic synthesis of dihydroxy fatty acids as lipid mediators from polyunsaturated fatty acids by double dioxygenation of the microbial 12S-lipoxygenase. Biotechnol Bioeng 2021; 118:3094-3104. [PMID: 33990936 DOI: 10.1002/bit.27820] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/04/2021] [Accepted: 05/09/2021] [Indexed: 12/14/2022]
Abstract
Leukotrienes (LTs) and maresins (MaRs) are human lipid mediators (LMs) involved in immune response and anti-inflammation, respectively. These compounds and their isomers are generated in trace amounts by lipoxygenases (LOXs) in human macrophages and neutrophils. These LMs have been synthesized using nonenvironmentally benign synthetic protocols, which are expensive. 8S- and 15S-LOXs with double dioxygenating activities have previously been reported, whereas 12S-LOX with double dioxygenating activity have not been reported to date. Here, we discovered a wild-type 12S-LOX with double dioxygenating activity from the bacterium Endozoicomonas numazuensis, which produced dihydroxy fatty acids (DiHFAs) as LMs from polyunsaturated fatty acids via double dioxygenation. The enzyme activity for producing DiHFA was approximately 550-fold higher than that of mammalian LOX with double dioxygenating activity. The microbial 12S-LOX converted 3.00 mM of arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid to 2.37 mM (797 mg/L) 6-trans-8-cis-12S-epimer of LTB4, 1.59 mM (532 mg/L) 6-trans-8-cis-12S-epimer of LTB5, 1.35 mM (498 mg/L) 10-cis-12-trans-7S-epimer of MaR1n-3 DPA , and 1.54 mM (555 mg/L) 10-cis-12-trans-7S-epimer of MaR1 within 2 h, which were 5.3-, 7.6-, 3.1-, and 5.5-fold higher than those biosynthesized by the previously reported microbial engineered 12S-LOX with double dioxygenating activity, respectively. These findings contribute to the efficient and environmentally friendly biosynthesis of LMs and stimulate physiological study on LMs.
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Affiliation(s)
- Tae-Hun Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Jin Lee
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Su-Eun Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Deok-Kun Oh
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
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4
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Korbecki J, Bobiński R, Dutka M. Self-regulation of the inflammatory response by peroxisome proliferator-activated receptors. Inflamm Res 2019; 68:443-458. [PMID: 30927048 PMCID: PMC6517359 DOI: 10.1007/s00011-019-01231-1] [Citation(s) in RCA: 194] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/24/2019] [Accepted: 03/22/2019] [Indexed: 12/14/2022] Open
Abstract
The peroxisome proliferator-activated receptor (PPAR) family includes three transcription factors: PPARα, PPARβ/δ, and PPARγ. PPAR are nuclear receptors activated by oxidised and nitrated fatty acid derivatives as well as by cyclopentenone prostaglandins (PGA2 and 15d-PGJ2) during the inflammatory response. This results in the modulation of the pro-inflammatory response, preventing it from being excessively activated. Other activators of these receptors are nonsteroidal anti-inflammatory drug (NSAID) and fatty acids, especially polyunsaturated fatty acid (PUFA) (arachidonic acid, ALA, EPA, and DHA). The main function of PPAR during the inflammatory reaction is to promote the inactivation of NF-κB. Possible mechanisms of inactivation include direct binding and thus inactivation of p65 NF-κB or ubiquitination leading to proteolytic degradation of p65 NF-κB. PPAR also exert indirect effects on NF-κB. They promote the expression of antioxidant enzymes, such as catalase, superoxide dismutase, or heme oxygenase-1, resulting in a reduction in the concentration of reactive oxygen species (ROS), i.e., secondary transmitters in inflammatory reactions. PPAR also cause an increase in the expression of IκBα, SIRT1, and PTEN, which interferes with the activation and function of NF-κB in inflammatory reactions.
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Affiliation(s)
- Jan Korbecki
- Department of Molecular Biology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18 Str., 40-752, Katowice, Poland. .,Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, University of Bielsko-Biala, Willowa 2 Str., 43-309, Bielsko-Biała, Poland.
| | - Rafał Bobiński
- Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, University of Bielsko-Biala, Willowa 2 Str., 43-309, Bielsko-Biała, Poland
| | - Mieczysław Dutka
- Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, University of Bielsko-Biala, Willowa 2 Str., 43-309, Bielsko-Biała, Poland
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5
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Kolmert J, Piñeiro-Hermida S, Hamberg M, Gregory JA, López IP, Fauland A, Wheelock CE, Dahlén SE, Pichel JG, Adner M. Prominent release of lipoxygenase generated mediators in a murine house dust mite-induced asthma model. Prostaglandins Other Lipid Mediat 2018; 137:20-29. [PMID: 29763661 DOI: 10.1016/j.prostaglandins.2018.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/06/2018] [Accepted: 05/09/2018] [Indexed: 01/08/2023]
Abstract
The profile of activation of lipid mediator (LM) pathways in asthmatic airway inflammation remains unclear. This experimental study quantified metabolite levels of ω3-, ω6- and ω9-derived polyunsaturated fatty acids in bronchoalveolar lavage fluid (BALF) after 4-weeks of repeated house dust mite (HDM) exposure in a murine (C57BL/6) asthma model. The challenge induced airway hyperresponsiveness, pulmonary eosinophil infiltration, but with low and unchanged mast cell numbers. Of the 112 screened LMs, 26 were increased between 2 to >25-fold in BALF with HDM treatment (p < 0.05, false discovery rate = 5%). While cysteinyl-leukotrienes were the most abundant metabolites at baseline, their levels did not increase after HDM treatment, whereas elevation of PGD2, LTB4 and multiple 12/15-lipoxygenase products, such as 5,15-DiHETE, 15-HEDE and 15-HEPE were observed. We conclude that this model has identified a global lipoxygenase activation signature, not linked to mast cells, but with aspects that mimic chronic allergic airway inflammation in asthma.
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Affiliation(s)
- Johan Kolmert
- Unit for Experimental Asthma and Allergy Research, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Sergio Piñeiro-Hermida
- Lung Cancer and Respiratory Diseases Unit, Centro de Investigación Biomédica de la Rioja (CIBIR), Fundación Rioja Salud, Logroño, Spain
| | - Mats Hamberg
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Joshua A Gregory
- Unit for Experimental Asthma and Allergy Research, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Icíar P López
- Lung Cancer and Respiratory Diseases Unit, Centro de Investigación Biomédica de la Rioja (CIBIR), Fundación Rioja Salud, Logroño, Spain
| | - Alexander Fauland
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Craig E Wheelock
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Sven-Erik Dahlén
- Unit for Experimental Asthma and Allergy Research, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - José G Pichel
- Lung Cancer and Respiratory Diseases Unit, Centro de Investigación Biomédica de la Rioja (CIBIR), Fundación Rioja Salud, Logroño, Spain
| | - Mikael Adner
- Unit for Experimental Asthma and Allergy Research, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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6
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Tumor-Suppressive Lipoxygenases Inhibit the Expression of c-mycmRNA Coding Region Determinant-Binding Protein/Insulin-Like Growth Factor II mRNA-Binding Protein 1 in Human Prostate Carcinoma PC-3 Cells. Biosci Biotechnol Biochem 2014; 73:1811-7. [DOI: 10.1271/bbb.90185] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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Wege N, Schutkowski A, König B, Brandsch C, Weiwad M, Stangl GI. PPARα modulates the TSH β-subunit mRNA expression in thyrotrope TαT1 cells and in a mouse model. Mol Nutr Food Res 2012; 57:376-89. [PMID: 23255496 DOI: 10.1002/mnfr.201200409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/23/2012] [Accepted: 10/30/2012] [Indexed: 11/07/2022]
Abstract
SCOPE Fasting leads to a significant downregulation of the hypothalamus-pituitary-thyroid axis, and peroxisome proliferator-activated receptor (PPAR) α is a key transcription factor in mediating a magnitude of adaptive responses to fasting. In this study, we examined the role of PPARα in regulation of the hypothalamus-pituitary-thyroid axis. METHODS AND RESULTS Thyroid-stimulating hormone β-subunit (TSHβ) mRNA abundance was being reduced in response to treatment of TαT1 cells with PPARα agonists (p < 0.05), indicating an inhibitory transcriptional regulation of TSHβ by PPARα. As expected, fasting significantly downregulated TSHβ mRNA expression in a two-factorial study with fed or fasted wild-type (WT) and PPARα knockout mice (p < 0.05). In contrast to the in vitro data, fasted PPARα knockout mice revealed lower mRNA concentrations of pituitary TSHβ (-64%) and TSH-regulated thyroid genes, and lower plasma concentrations of thyroxine (T4, -25%), triiodothyronine (T3, -25%), free T4 (-60%), and free T3 (-35%) than fasted WT mice (p < 0.05). Those differences were not observed in fed mice. CONCLUSIONS Data from thyrotrope cells revealed that PPARα could contribute to the fasting-associated downregulation of the TSHβ mRNA expression. In a mouse model, fasting led to a significant reduction in TSHβ mRNA level, but unexpectedly this effect was stronger in mice lacking PPARα than in WT mice.
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Affiliation(s)
- Nicole Wege
- Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
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8
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Eek P, Järving R, Järving I, Gilbert NC, Newcomer ME, Samel N. Structure of a calcium-dependent 11R-lipoxygenase suggests a mechanism for Ca2+ regulation. J Biol Chem 2012; 287:22377-86. [PMID: 22573333 DOI: 10.1074/jbc.m112.343285] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipoxygenases (LOXs) are a key part of several signaling pathways that lead to inflammation and cancer. Yet, the mechanisms of substrate binding and allosteric regulation by the various LOX isoforms remain speculative. Here we report the 2.47-Å resolution crystal structure of the arachidonate 11R-LOX from Gersemia fruticosa, which sheds new light on the mechanism of LOX catalysis. Our crystallographic and mutational studies suggest that the aliphatic tail of the fatty acid is bound in a hydrophobic pocket with two potential entrances. We speculate that LOXs share a common T-shaped substrate channel architecture that gives rise to the varying positional specificities. A general allosteric mechanism is proposed for transmitting the activity-inducing effect of calcium binding from the membrane-targeting PLAT (polycystin-1/lipoxygenase/α-toxin) domain to the active site via a conserved π-cation bridge.
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Affiliation(s)
- Priit Eek
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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9
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Goto T, Lee JY, Teraminami A, Kim YI, Hirai S, Uemura T, Inoue H, Takahashi N, Kawada T. Activation of peroxisome proliferator-activated receptor-alpha stimulates both differentiation and fatty acid oxidation in adipocytes. J Lipid Res 2011; 52:873-84. [PMID: 21324916 PMCID: PMC3073464 DOI: 10.1194/jlr.m011320] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Peroxisome proliferator-activated receptor-α (PPARα) is a dietary lipid sensor, whose activation results in hypolipidemic effects. In this study, we investigated whether PPARα activation affects energy metabolism in white adipose tissue (WAT). Activation of PPARα by its agonist (bezafibrate) markedly reduced adiposity in KK mice fed a high-fat diet. In 3T3-L1 adipocytes, addition of GW7647, a highly specific PPARα agonist, during adipocyte differentiation enhanced glycerol-3-phosphate dehydrogenase activity, insulin-stimulated glucose uptake, and adipogenic gene expression. However, triglyceride accumulation was not increased by PPARα activation. PPARα activation induced expression of target genes involved in FA oxidation and stimulated FA oxidation. In WAT of KK mice treated with bezafibrate, both adipogenic and FA oxidation-related genes were significantly upregulated. These changes in mRNA expression were not observed in PPARα-deficient mice. Bezafibrate treatment enhanced FA oxidation in isolated adipocytes, suppressing adipocyte hypertrophy. Chromatin immunoprecipitation (ChIP) assay revealed that PPARα was recruited to promoter regions of both adipogenic and FA oxidation-related genes in the presence of GW7647 in 3T3-L1 adipocytes. These findings indicate that the activation of PPARα affects energy metabolism in adipocytes, and PPARα activation in WAT may contribute to the clinical effects of fibrate drugs.
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Affiliation(s)
- Tsuyoshi Goto
- Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
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Buczynski MW, Dumlao DS, Dennis EA. Thematic Review Series: Proteomics. An integrated omics analysis of eicosanoid biology. J Lipid Res 2009; 50:1015-38. [PMID: 19244215 PMCID: PMC2681385 DOI: 10.1194/jlr.r900004-jlr200] [Citation(s) in RCA: 397] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 02/23/2009] [Indexed: 11/20/2022] Open
Abstract
Eicosanoids have been implicated in a vast number of devastating inflammatory conditions, including arthritis, atherosclerosis, pain, and cancer. Currently, over a hundred different eicosanoids have been identified, with many having potent bioactive signaling capacity. These lipid metabolites are synthesized de novo by at least 50 unique enzymes, many of which have been cloned and characterized. Due to the extensive characterization of eicosanoid biosynthetic pathways, this field provides a unique framework for integrating genomics, proteomics, and metabolomics toward the investigation of disease pathology. To facilitate a concerted systems biology approach, this review outlines the proteins implicated in eicosanoid biosynthesis and signaling in human, mouse, and rat. Applications of the extensive genomic and lipidomic research to date illustrate the questions in eicosanoid signaling that could be uniquely addressed by a thorough analysis of the entire eicosanoid proteome.
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Affiliation(s)
| | | | - Edward A. Dennis
- Department of Chemistry and Biochemistry, Department of Pharmacology, and School of Medicine, University of California, San Diego, La Jolla, CA 92093
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Hajek AR, Lindley AR, Favoreto S, Carter R, Schleimer RP, Kuperman DA. 12/15-Lipoxygenase deficiency protects mice from allergic airways inflammation and increases secretory IgA levels. J Allergy Clin Immunol 2008; 122:633-9.e3. [PMID: 18692885 DOI: 10.1016/j.jaci.2008.06.021] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 06/17/2008] [Accepted: 06/18/2008] [Indexed: 11/25/2022]
Abstract
BACKGROUND Induction of 15-lipoxygenase-1 (15-LO-1) has been observed in the airways of subjects with asthma, although its physiologic role in the airways has remained largely undefined. OBJECTIVES We sought to test the hypothesis that the mouse 15-LO-1 ortholog 12/15-LO contributes to the development of allergic airways inflammation. METHODS Two models were used to evaluate wild-type and 12/15-LO-deficient mice. The systemic model involved intraperitoneal injections of allergen, and the mucosal model involved allergen exposures occurring exclusively in the airways. The systemic and mucosal-specific contributions of 12/15-LO to allergic sensitization and airways inflammation were determined by comparing the results obtained in the 2 models. RESULTS In the mucosal model 12/15-LO knockout mice were protected from the development of allergic sensitization and airways inflammation, as evidenced by circulating levels of allergen-specific IgE, IgG1, and IgG2a; the profile of inflammatory cells in bronchoalveolar lavage fluid; and the expression of cytokines and mediators in lung tissue. In the systemic model 12/15-LO knockout mice were not protected. This suggested the presence of a lung-restricted protective role for 12/15-LO deficiency that was potentially accounted for by increased activation of mucosal B cells and increased production of the known mucosal-specific protective mediator secretory IgA. CONCLUSIONS Induction of 15-LO-1 in asthma might contribute to allergic sensitization and airways inflammation, potentially by causing suppression of secretory IgA.
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Affiliation(s)
- Amanda R Hajek
- Department of Medicine, Allergy-Immunology Division, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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12
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Yamamoto S, Katsukawa M, Nakano A, Hiraki E, Nishimura K, Jisaka M, Yokota K, Ueda N. Arachidonate 12-lipoxygenases with reference to their selective inhibitors. Biochem Biophys Res Commun 2005; 338:122-7. [PMID: 16171776 DOI: 10.1016/j.bbrc.2005.08.214] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 08/30/2005] [Indexed: 11/22/2022]
Abstract
Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxyeicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitiol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-gallocatechin gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC50 of 0.14 microM. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclooxygenases-1 and -2.
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Affiliation(s)
- Shozo Yamamoto
- Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501, Japan.
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