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Skóra B, Piechowiak T, Szychowski KA. Dual mechanism of silver nanoparticle-mediated upregulation of adipogenesis in mouse fibroblasts (3T3-L1) in vitro. Toxicol Appl Pharmacol 2023; 479:116726. [PMID: 37844778 DOI: 10.1016/j.taap.2023.116726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/04/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Silver nanoparticles (AgNPs) are widespread in the environment due to the increase in their application e.g. in medicine as part of hard-to-heal wound dressings. Many studies have revealed easy diffusion of AgNPs into deep skin layers through damaged epidermis and contact with e.g. fibroblasts. Therefore, the aim of this study was to evaluate the impact of small-size AgNPs (10 nm) in ppm concentrations on the adipogenesis process in mouse embryo fibroblasts (3T3-L1). The results showed a decrease in the metabolic activity, followed by an increase in the reactive oxygen species (ROS) level in a dose- and time-dependent manner (0-20 ppm). The increased caspase-3 activity was observed only at the highest concentration (20 ppm) of AgNPs. Further analysis showed the ability of the tested NPs to increase the lipid accumulation in adipocytes, similar to ROSI [peroxisome proliferator-activated receptor gamma (PPARγ) agonist], measured by Oil-Red-O staining. Moreover, the analyses evidenced the ability of AgNPs to increase the lipoxygenase activity and malondialdehyde levels, which is probably based on ROS-dependent enhancement of lipid hydroperoxidation. Lastly, a significant increase in the PPARγ, Adiponectin, Resistin, Vegf, and Serpine mRNA expression was shown 6 h after the induction of the differentiation process. Based on the obtained results, it can be concluded that small-size AgNPs increase adipogenesis via ROS- and PPARγ-based mechanisms with potential engagement of crosstalk with the aryl hydrocarbon receptor, which is important due to the widespread application of AgNPs in medicine. However, more studies are needed to elucidate the full mechanism of these NPs in the tested cell model in depth.
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Affiliation(s)
- Bartosz Skóra
- Department of Biotechnology and Cell Biology, Medical College, University of Information Technology and Management, St. Sucharskiego 2, 35-225 Rzeszow, Poland.
| | - Tomasz Piechowiak
- Department of Chemistry and Food Toxicology, Institute of Food Technology and Nutrition, University of Rzeszow, St. Cwiklinskiej 1A, 35-601 Rzeszow, Poland
| | - Konrad A Szychowski
- Department of Biotechnology and Cell Biology, Medical College, University of Information Technology and Management, St. Sucharskiego 2, 35-225 Rzeszow, Poland
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2
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Pseudophosphorylation of Arabidopsis jasmonate biosynthesis enzyme lipoxygenase 2 via mutation of Ser 600 inhibits enzyme activity. J Biol Chem 2023; 299:102898. [PMID: 36639029 PMCID: PMC9947334 DOI: 10.1016/j.jbc.2023.102898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 01/12/2023] Open
Abstract
Jasmonates are oxylipin phytohormones critical for plant resistance against necrotrophic pathogens and chewing herbivores. An early step in their biosynthesis is catalyzed by non-heme iron lipoxygenases (LOX; EC 1.13.11.12). In Arabidopsis thaliana, phosphorylation of Ser600 of AtLOX2 was previously reported, but whether phosphorylation regulates AtLOX2 activity is unclear. Here, we characterize the kinetic properties of recombinant WT AtLOX2 (AtLOX2WT). AtLOX2WT displays positive cooperativity with α-linolenic acid (α-LeA, jasmonate precursor), linoleic acid (LA), and arachidonic acid (AA) as substrates. Enzyme velocity with endogenous substrates α-LeA and LA increased with pH. For α-LeA, this increase was accompanied by a decrease in substrate affinity at alkaline pH; thus, the catalytic efficiency for α-LeA was not affected over the pH range tested. Analysis of Ser600 phosphovariants demonstrated that pseudophosphorylation inhibits enzyme activity. AtLOX2 activity was not detected in phosphomimics Atlox2S600D and Atlox2S600M when α-LeA or AA were used as substrates. In contrast, phosphonull mutant Atlox2S600A exhibited strong activity with all three substrates, α-LeA, LA, and AA. Structural comparison between the AtLOX2 AlphaFold model and a complex between 8R-LOX and a 20C polyunsaturated fatty acid suggests a close proximity between AtLOX2 Ser600 and the carboxylic acid head group of the polyunsaturated fatty acid. This analysis indicates that Ser600 is located at a critical position within the AtLOX2 structure and highlights how Ser600 phosphorylation could affect AtLOX2 catalytic activity. Overall, we propose that AtLOX2 Ser600 phosphorylation represents a key mechanism for the regulation of AtLOX2 activity and, thus, the jasmonate biosynthesis pathway and plant resistance.
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3
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Bacterial lipoxygenases: Biochemical characteristics, molecular structure and potential applications. Biotechnol Adv 2022; 61:108046. [DOI: 10.1016/j.biotechadv.2022.108046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/02/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022]
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Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging. Biomedicines 2022; 10:biomedicines10061379. [PMID: 35740398 PMCID: PMC9220125 DOI: 10.3390/biomedicines10061379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 01/09/2023] Open
Abstract
Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional Alox genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15S-HpETE), whereas 8S-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created Alox15b knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male Alox15b-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male Alox15b-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.
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Structural considerations on lipoxygenase function, inhibition and crosstalk with nitric oxide pathways. Biochimie 2020; 178:170-180. [PMID: 32980463 DOI: 10.1016/j.biochi.2020.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 09/10/2020] [Accepted: 09/22/2020] [Indexed: 12/30/2022]
Abstract
Lipoxygenases (LOX) are non-heme iron-containing enzymes that catalyze regio- and stereo-selective dioxygenation of polyunsaturated fatty acids (PUFA). Mammalian LOXs participate in the eicosanoid cascade during the inflammatory response, using preferentially arachidonic acid (AA) as substrate, for the synthesis of leukotrienes (LT) and other oxidized-lipid intermediaries. This review focus on lipoxygenases (LOX) structural and kinetic implications on both catalysis selectivity, as well as the basic and clinical implications of inhibition and interactions with nitric oxide (•NO) and nitroalkenes pathways. During inflammation •NO levels are increasingly favoring the formation of reactive nitrogen species (RNS). •NO may act itself as an inhibitor of LOX-mediated lipid oxidation by reacting with lipid peroxyl radicals. Besides, •NO may act as an O2 competitor in the LOX active site, thus displaying a protective role on lipid-peroxidation. Moreover, RNS such as nitrogen dioxide (•NO2) may react with lipid-derived species formed during LOX reaction, yielding nitroalkenes (NO2FA). NO2FA represents electrophilic compounds that could exert anti-inflammatory actions through the interaction with critical LOX nucleophilic amino acids. We will discuss how nitro-oxidative conditions may limit the availability of common LOX substrates, favoring alternative routes of PUFA metabolization to anti-inflammatory or pro-resolutive pathways.
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Biringer RG. The enzymology of human eicosanoid pathways: the lipoxygenase branches. Mol Biol Rep 2020; 47:7189-7207. [PMID: 32748021 DOI: 10.1007/s11033-020-05698-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/26/2020] [Indexed: 12/16/2022]
Abstract
Eicosanoids are short-lived derivatives of polyunsaturated fatty acids that serve as autocrine and paracrine signaling molecules. They are involved numerous biological processes of both the well state and disease states. A thorough understanding of the progression the disease state and homeostasis of the well state requires a complete evaluation of the systems involved. This review examines the enzymology for the enzymes involved in the production of eicosanoids along the lipoxygenase branches of the eicosanoid pathways with particular emphasis on those derived from arachidonic acid. The enzymatic parameters, protocols to measure them, and proposed catalytic mechanisms are presented in detail.
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Affiliation(s)
- Roger Gregory Biringer
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, Bradenton, FL, 34211, USA.
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Reisch F, Kakularam KR, Stehling S, Heydeck D, Kuhn H. Eicosanoid biosynthesis in marine mammals. FEBS J 2020; 288:1387-1406. [PMID: 32627384 DOI: 10.1111/febs.15469] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 05/19/2020] [Accepted: 06/22/2020] [Indexed: 01/09/2023]
Abstract
After 300 million years of evolution, the first land-living mammals reentered the marine environment some 50 million years ago. The driving forces for this dramatic lifestyle change are still a matter of discussion but the struggle for food resources and the opportunity to escape predators probably contributed. Reentering the oceans requires metabolic adaption putting evolutionary pressure on a number of genes. To explore whether eicosanoid signaling has been part of this adaptive response, we first explored whether the genomes of marine mammals involve functional genes encoding for key enzymes of eicosanoid biosynthesis. Cyclooxygenase (COX) and lipoxygenase (ALOX) genes are present in the genome of all marine mammals tested. Interestingly, ALOX12B, which has been implicated in skin development of land-living mammals, is lacking in whales and dolphins and genes encoding for its sister enzyme (ALOXE3) involve premature stop codons and/or frameshifting point mutations, which interrupt the open reading frames. ALOX15 orthologs have been detected in all marine mammals, and the recombinant enzymes exhibit similar catalytic properties as those of land-living species. All marine mammals express arachidonic acid 12-lipoxygenating ALOX15 orthologs, and these data are consistent with the Evolutionary Hypothesis of ALOX15 specificity. These enzymes exhibit membrane oxygenase activity and introduction of big amino acids at the triad positions altered the reaction specificity in favor of arachidonic acid 15-lipoxygenation. Thus, the ALOX15 orthologs of marine mammals follow the Triad concept explaining their catalytic specificity.
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Affiliation(s)
- Florian Reisch
- Institute of Biochemistry, Charité - University Medicine Berlin, Corporate member of Free University Berlin, Humboldt University Berlin and Berlin Institute of Health, Berlin, Germany
| | - Kumar Reddy Kakularam
- Institute of Biochemistry, Charité - University Medicine Berlin, Corporate member of Free University Berlin, Humboldt University Berlin and Berlin Institute of Health, Berlin, Germany
| | - Sabine Stehling
- Institute of Biochemistry, Charité - University Medicine Berlin, Corporate member of Free University Berlin, Humboldt University Berlin and Berlin Institute of Health, Berlin, Germany
| | - Dagmar Heydeck
- Institute of Biochemistry, Charité - University Medicine Berlin, Corporate member of Free University Berlin, Humboldt University Berlin and Berlin Institute of Health, Berlin, Germany
| | - Hartmut Kuhn
- Institute of Biochemistry, Charité - University Medicine Berlin, Corporate member of Free University Berlin, Humboldt University Berlin and Berlin Institute of Health, Berlin, Germany
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Gaffney BJ. EPR Spectroscopic Studies of Lipoxygenases. Chem Asian J 2019; 15:42-50. [PMID: 31782616 DOI: 10.1002/asia.201901461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/27/2019] [Indexed: 11/11/2022]
Abstract
Polyunsaturated fatty acids are sources of diverse natural, and chemically designed products. The enzyme lipoxygenase selectively oxidizes fatty acid acyl chains using controlled free radical chemistry; the products are regio- and stereo-chemically unique hydroperoxides. A conserved structural fold of ≈600 amino acids harbors a long and narrow substrate channel and a well-shielded catalytic iron. Oxygen, a co-substrate, is blocked from the active site until a hydrogen atom is abstracted from substrate bis-allylic carbon, in a non-heme iron redox cycle. EPR spectroscopy of ferric intermediates in lipoxygenase catalysis reveals changes in the metal coordination and leads to a proposal on the nature of the reactive intermediate. Remarkably, free radicals are so well controlled in lipoxygenase chemistry that spin label technology can be applied as well. The current level of understanding of steps in lipoxygenase catalysis, from the EPR perspective, will be reviewed.
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Affiliation(s)
- Betty J Gaffney
- Biological Science, Florida State University, Tallahassee, FL, 32306, USA
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Chong WK, Mah SY, Easa AM, Tan TC. Thermal inactivation of lipoxygenase in soya bean using superheated steam to produce low beany flavour soya milk. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2019; 56:4371-4379. [PMID: 31478006 DOI: 10.1007/s13197-019-03905-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/13/2019] [Accepted: 06/25/2019] [Indexed: 10/26/2022]
Abstract
Time and temperature parameters of superheated steam (SHS) treatment were optimised using response surface methodology (RSM) for specific lipoxygenase (LOX) activity in soya beans and crude protein content in soya milk. The optimal SHS treatment was obtained at 9.3 min and 119 °C. The predicted values of specific LOX activity and crude protein content by RSM were 0.0098 μmol/(min mg protein) and 3.2%, respectively. These values were experimentally verified to be 0.0081 ± 0.0002 μmol/(min mg protein) and 3.0 ± 0.1%, respectively. Sensory evaluation showed that the beany flavour of soya milk produced from SHS treated soya beans was significantly weaker (P < 0.05) than that of untreated soya beans. The results showed that the optimised SHS treatment could reduce the beany flavour in the soya milk significantly (P < 0.05) by reducing the specific LOX activity in the soybean, while ensuring the crude protein content in the soya milk complied with Malaysian Food Regulations 1985.
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Affiliation(s)
- Wah-Kang Chong
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 USM, Penang Malaysia
| | - Sook-Yun Mah
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 USM, Penang Malaysia
| | - Azhar Mat Easa
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 USM, Penang Malaysia
| | - Thuan-Chew Tan
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 USM, Penang Malaysia
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Gào X, Zhang Y, Burwinkel B, Xuan Y, Holleczek B, Brenner H, Schöttker B. The associations of DNA methylation alterations in oxidative stress-related genes with cancer incidence and mortality outcomes: a population-based cohort study. Clin Epigenetics 2019; 11:14. [PMID: 30678711 PMCID: PMC6346508 DOI: 10.1186/s13148-018-0604-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/20/2018] [Indexed: 12/20/2022] Open
Abstract
Background Reactive oxygen species may be involved in epigenetic gene activation or silencing. We aimed to identify CpG sites, at which DNA methylation is related to urinary 8-isoprostane levels (biomarker of lipid peroxidation) and cancer or mortality outcomes. This investigation was based on a German, population-based cohort with linkage to cancer and mortality registry data (2000–2016). Results Blood DNA methylation in promoter regions of 519 genes, known to be involved in pathways from oxidative stress (OS) to cancer, was obtained at the cohort's baseline examination. Inverse associations of DNA methylation at cg25365794 (ALOXE3) and cg08862778 (MTOR) with 8-isoprostane levels were observed in a derivation set (n = 1000) and validated in two independent subsets of the cohort (n = 548 and n = 741). Multivariate regression models were used to evaluate the associations of DNA methylation at the two CpG sites with lung, colorectal, prostate, breast, and overall cancer incidence as well as CVD, cancer, and all-cause mortality. DNA methylation at cg25365794 (ALOXE3) was inversely associated with lung and prostate cancer incidence. DNA methylation at cg08862778 (MTOR) was associated with a 43% lower breast cancer incidence in the top vs. bottom tertile. Conclusion The finding for ALOXE3 may not be causal. As ALOXE3 is mainly expressed in skin tissue, the observed association might reflect the fact that both DNA methylation at the ALOXE3 gene and urinary 8-isoprostane concentrations depend on the level of OS in tissues. Contrarily, the finding for the MTOR gene and breast cancer is biologically plausible because the MTOR protein plays an important role in PI3K/Akt signaling, which is a pathway related to cancer development and cell senescence. Electronic supplementary material The online version of this article (10.1186/s13148-018-0604-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xīn Gào
- Division of Clinical Epidemiology and Ageing Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,Network Aging Research, University of Heidelberg, Bergheimer Straße 20, 69115, Heidelberg, Germany
| | - Yan Zhang
- Division of Clinical Epidemiology and Ageing Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Barbara Burwinkel
- Division of Molecular Epidemiology, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,Division Molecular Biology of Breast Cancer, University Women's Clinic, Heidelberg University, Voßstraße 9, 69115, Heidelberg, Germany
| | - Yang Xuan
- Division of Clinical Epidemiology and Ageing Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,Network Aging Research, University of Heidelberg, Bergheimer Straße 20, 69115, Heidelberg, Germany
| | - Bernd Holleczek
- Saarland Cancer Registry, Krebsregister Saarland, Präsident-Baltz-Straße 5, 66119, Saarbrücken, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Ageing Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,Network Aging Research, University of Heidelberg, Bergheimer Straße 20, 69115, Heidelberg, Germany.,Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Ben Schöttker
- Division of Clinical Epidemiology and Ageing Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany. .,Network Aging Research, University of Heidelberg, Bergheimer Straße 20, 69115, Heidelberg, Germany.
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Gehring T, Heydeck D, Niewienda A, Janek K, Kuhn H. Do lipoxygenases occur in viruses?: Expression and characterization of a viral lipoxygenase-like protein did not provide evidence for the existence of functional viral lipoxygenases. Prostaglandins Leukot Essent Fatty Acids 2018; 138:14-23. [PMID: 30392576 DOI: 10.1016/j.plefa.2018.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/24/2018] [Accepted: 10/03/2018] [Indexed: 01/13/2023]
Abstract
Lipoxygenases are lipid peroxidizing enzymes, which frequently occur in higher plants and animals. In bacteria, these enzymes are rare and have been introduced via horizontal gene transfer. Since viruses function as horizontal gene transfer vectors and since lipoxygenases may be helpful for releasing assembled virus particles from host cells we explored whether these enzymes may actually occur in viruses. For this purpose we developed a four-step in silico screening strategy and searching the publically available viral genomes for lipoxygenase-like sequences we detected a single functional gene in the genome of a mimivirus infecting Acantamoeba polyphaga. The primary structure of this protein involved two putative metal ligand clusters but the recombinant enzyme did neither contain iron nor manganese. Most importantly, it did not exhibit lipoxygenase activity. These data suggests that this viral lipoxygenase-like sequence does not encode a functional lipoxygenase and that these enzymes do not occur in viruses.
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Affiliation(s)
- Tatjana Gehring
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Dagmar Heydeck
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Agathe Niewienda
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Core facility for Mass Spectrometry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Katharina Janek
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Core facility for Mass Spectrometry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Hartmut Kuhn
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, D-10117 Berlin, Germany.
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Del Ángel-Coronel OA, León-García E, Vela-Gutiérrez G, Rojas-Reyes JO, Gómez-Lim MÁ, García HS. Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium eduleJacq. Sw. cv. “virens levis”). J Food Biochem 2017. [DOI: 10.1111/jfbc.12438] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Oscar Andrés Del Ángel-Coronel
- Unidad de Investigación y Desarrollo en Alimentos, Instituto Tecnológico de Veracruz, Miguel Ángel de Quevedo 2779; Veracruz Ver. 91897 México
- Instituto Tecnológico Superior de Huatusco, Av. 25 Poniente No. 100, Col. Reserva Territorial, Huatusco; Veracruz, C.P. 94100 México
| | - Elizabeth León-García
- Unidad de Investigación y Desarrollo en Alimentos, Instituto Tecnológico de Veracruz, Miguel Ángel de Quevedo 2779; Veracruz Ver. 91897 México
| | - Gilber Vela-Gutiérrez
- Unidad de Investigación y Desarrollo en Alimentos, Instituto Tecnológico de Veracruz, Miguel Ángel de Quevedo 2779; Veracruz Ver. 91897 México
- Facultad de Ciencias de la Nutrición y Alimentos, Universidad de Ciencias y Artes de Chiapas, Lib. Nte. Pte. No. 1150, Ciudad Universitaria, Col. Lajas Maciel; Tuxtla Gutiérrez Chiapas, C.P. 29000 México
| | - José Orlando Rojas-Reyes
- Centro Regional Universitario Oriente, Universidad Autónoma Chapingo, Km. 6 Carretera Huatusco-Xalapa; Huatusco Veracruz, C.P. 94100 México
| | - Miguel Ángel Gómez-Lim
- Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Unidad Irapuato, Km. 9.6 Lib. Nte. Carretera León; Irapuato Guanajuato, C.P. 36821 México
| | - Hugo Sergio García
- Unidad de Investigación y Desarrollo en Alimentos, Instituto Tecnológico de Veracruz, Miguel Ángel de Quevedo 2779; Veracruz Ver. 91897 México
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Teder T, Boeglin WE, Schneider C, Brash AR. A fungal catalase reacts selectively with the 13S fatty acid hydroperoxide products of the adjacent lipoxygenase gene and exhibits 13S-hydroperoxide-dependent peroxidase activity. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:706-715. [PMID: 28363790 DOI: 10.1016/j.bbalip.2017.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 03/08/2017] [Accepted: 03/27/2017] [Indexed: 11/16/2022]
Abstract
The genome of the fungal plant pathogen Fusarium graminearum harbors six catalases, one of which has the sequence characteristics of a fatty acid peroxide-metabolizing catalase. We cloned and expressed this hemoprotein (designated as Fg-cat) along with its immediate neighbor, a 13S-lipoxygenase (cf. Brodhun et al., PloS One, e64919, 2013) that we considered might supply a fatty acid hydroperoxide substrate. Indeed, Fg-cat reacts abruptly with the 13S-hydroperoxide of linoleic acid (13S-HPODE) with an initial rate of 700-1300s-1. By comparison there was no reaction with 9R- or 9S-HPODEs and extremely weak reaction with 13R-HPODE (~0.5% of the rate with 13S-HPODE). Although we considered Fg-cat as a candidate for the allene oxide synthase of the jasmonate pathway in fungi, the main product formed from 13S-HPODE was identified by UV, MS, and NMR as 9-oxo-10E-12,13-cis-epoxy-octadecenoic acid (with no traces of AOS activity). The corresponding analog is formed from the 13S-hydroperoxide of α-linolenic acid along with novel diepoxy-ketones and two C13 aldehyde derivatives, the reaction mechanisms of which are proposed. In a peroxidase assay monitoring the oxidation of ABTS, Fg-cat exhibited robust activity (kcat 550s-1) using the 13S-hydroperoxy-C18 fatty acids as the oxidizing co-substrate. There was no detectable peroxidase activity using the corresponding 9S-hydroperoxides, nor with t-butyl hydroperoxide, and very weak activity with H2O2 or cumene hydroperoxide at micromolar concentrations of Fg-cat. Fg-cat and the associated lipoxygenase gene are present together in fungal genera Fusarium, Metarhizium and Fonsecaea and appear to constitute a partnership for oxidations in fungal metabolism or defense.
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Affiliation(s)
- Tarvi Teder
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - William E Boeglin
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Claus Schneider
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Alan R Brash
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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14
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Gandhi H, O'Reilly K, Gupta MK, Horgan C, O'Leary EM, O'Sullivan TP. Advances in the synthesis of acyclic peroxides. RSC Adv 2017. [DOI: 10.1039/c6ra28489b] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
This review summarises the many developments in the synthesis of acyclic peroxides, with a particular focus on the past 20 years, and seeks to update organic chemists about these new approaches.
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Affiliation(s)
- H. Gandhi
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - K. O'Reilly
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - M. K. Gupta
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - C. Horgan
- Department of Chemistry
- University College Cork
- Cork
- Ireland
| | - E. M. O'Leary
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - T. P. O'Sullivan
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
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15
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Chen Y, Wennman A, Karkehabadi S, Engström Å, Oliw EH. Crystal structure of linoleate 13R-manganese lipoxygenase in complex with an adhesion protein. J Lipid Res 2016; 57:1574-88. [PMID: 27313058 DOI: 10.1194/jlr.m069617] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Indexed: 11/20/2022] Open
Abstract
The crystal structure of 13R-manganese lipoxygenase (MnLOX) of Gaeumannomyces graminis (Gg) in complex with zonadhesin of Pichia pastoris was solved by molecular replacement. Zonadhesin contains β-strands in two subdomains. A comparison of Gg-MnLOX with the 9S-MnLOX of Magnaporthe oryzae (Mo) shows that the protein fold and the geometry of the metal ligands are conserved. The U-shaped active sites differ mainly due to hydrophobic residues of the substrate channel. The volumes and two hydrophobic side pockets near the catalytic base may sanction oxygenation at C-13 and C-9, respectively. Gly-332 of Gg-MnLOX is positioned in the substrate channel between the entrance and the metal center. Replacements with larger residues could restrict oxygen and substrate to reach the active site. C18 fatty acids are likely positioned with C-11 between Mn(2+)OH2 and Leu-336 for hydrogen abstraction and with one side of the 12Z double bond shielded by Phe-337 to prevent antarafacial oxygenation at C-13 and C-11. Phe-347 is positioned at the end of the substrate channel and replacement with smaller residues can position C18 fatty acids for oxygenation at C-9. Gg-MnLOX does not catalyze the sequential lipoxygenation of n-3 fatty acids in contrast to Mo-MnLOX, which illustrates the different configurations of their substrate channels.
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Affiliation(s)
- Yang Chen
- Department of Pharmaceutical Biosciences, Uppsala University Biomedical Center, SE-751 24 Uppsala, Sweden
| | - Anneli Wennman
- Department of Pharmaceutical Biosciences, Uppsala University Biomedical Center, SE-751 24 Uppsala, Sweden
| | - Saeid Karkehabadi
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Åke Engström
- Department of Biochemistry and Microbiology, Uppsala University Biomedical Center, SE-751 23 Uppsala, Sweden
| | - Ernst H Oliw
- Department of Pharmaceutical Biosciences, Uppsala University Biomedical Center, SE-751 24 Uppsala, Sweden
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16
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Mashima R, Okuyama T. The role of lipoxygenases in pathophysiology; new insights and future perspectives. Redox Biol 2015; 6:297-310. [PMID: 26298204 PMCID: PMC4556770 DOI: 10.1016/j.redox.2015.08.006] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/04/2015] [Accepted: 08/04/2015] [Indexed: 12/21/2022] Open
Abstract
Lipoxygenases (LOXs) are dioxygenases that catalyze the formation of corresponding hydroperoxides from polyunsaturated fatty acids such as linoleic acid and arachidonic acid. LOX enzymes are expressed in immune, epithelial, and tumor cells that display a variety of physiological functions, including inflammation, skin disorder, and tumorigenesis. In the humans and mice, six LOX isoforms have been known. 15-LOX, a prototypical enzyme originally found in reticulocytes shares the similarity of amino acid sequence as well as the biochemical property to plant LOX enzymes. 15-LOX-2, which is expressed in epithelial cells and leukocytes, has different substrate specificity in the humans and mice, therefore, the role of them in mammals has not been established. 12-LOX is an isoform expressed in epithelial cells and myeloid cells including platelets. Many mutations in this isoform are found in epithelial cancers, suggesting a potential link between 12-LOX and tumorigenesis. 12R-LOX can be found in the epithelial cells of the skin. Defects in this gene result in ichthyosis, a cutaneous disorder characterized by pathophysiologically dried skin due to abnormal loss of water from its epithelial cell layer. Similarly, eLOX-3, which is also expressed in the skin epithelial cells acting downstream 12R-LOX, is another causative factor for ichthyosis. 5-LOX is a distinct isoform playing an important role in asthma and inflammation. This isoform causes the constriction of bronchioles in response to cysteinyl leukotrienes such as LTC4, thus leading to asthma. It also induces neutrophilic inflammation by its recruitment in response to LTB4. Importantly, 5-LOX activity is strictly regulated by 5-LOX activating protein (FLAP) though the distribution of 5-LOX in the nucleus. Currently, pharmacological drugs targeting FLAP are actively developing. This review summarized these functions of LOX enzymes under pathophysiological conditions in mammals.
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Affiliation(s)
- Ryuichi Mashima
- Department of Clinical Laboratory Medicine, National Center for Child Health and Development, 2-10-1 Ohkura, Setagaya-ku, Tokyo 157-8535, Japan.
| | - Torayuki Okuyama
- Department of Clinical Laboratory Medicine, National Center for Child Health and Development, 2-10-1 Ohkura, Setagaya-ku, Tokyo 157-8535, Japan
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17
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ul Hassan MN, Zainal Z, Ismail I. Green leaf volatiles: biosynthesis, biological functions and their applications in biotechnology. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:727-39. [PMID: 25865366 DOI: 10.1111/pbi.12368] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 02/25/2015] [Accepted: 02/25/2015] [Indexed: 05/25/2023]
Abstract
Plants have evolved numerous constitutive and inducible defence mechanisms to cope with biotic and abiotic stresses. These stresses induce the expression of various genes to activate defence-related pathways that result in the release of defence chemicals. One of these defence mechanisms is the oxylipin pathway, which produces jasmonates, divinylethers and green leaf volatiles (GLVs) through the peroxidation of polyunsaturated fatty acids (PUFAs). GLVs have recently emerged as key players in plant defence, plant-plant interactions and plant-insect interactions. Some GLVs inhibit the growth and propagation of plant pathogens, including bacteria, viruses and fungi. In certain cases, GLVs released from plants under herbivore attack can serve as aerial messengers to neighbouring plants and to attract parasitic or parasitoid enemies of the herbivores. The plants that perceive these volatile signals are primed and can then adapt in preparation for the upcoming challenges. Due to their 'green note' odour, GLVs impart aromas and flavours to many natural foods, such as vegetables and fruits, and therefore, they can be exploited in industrial biotechnology. The aim of this study was to review the progress and recent developments in research on the oxylipin pathway, with a specific focus on the biosynthesis and biological functions of GLVs and their applications in industrial biotechnology.
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Affiliation(s)
- Muhammad Naeem ul Hassan
- Faculty of Science and Technology, School of Bioscience and Biotechnology, University Kebangsaan Malaysia, Bangi, Malaysia
- Department of Chemistry, University of Sargodha, Sargodha, Pakistan
| | - Zamri Zainal
- Faculty of Science and Technology, School of Bioscience and Biotechnology, University Kebangsaan Malaysia, Bangi, Malaysia
- Institute of Systems Biology (INBIOSIS), University Kebangsaan Malaysia, Bangi, Malaysia
| | - Ismanizan Ismail
- Faculty of Science and Technology, School of Bioscience and Biotechnology, University Kebangsaan Malaysia, Bangi, Malaysia
- Institute of Systems Biology (INBIOSIS), University Kebangsaan Malaysia, Bangi, Malaysia
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18
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Abstract
Lipoxygenases (LOX) form a family of lipid peroxidizing enzymes, which have been implicated in a number of physiological processes and in the pathogenesis of inflammatory, hyperproliferative and neurodegenerative diseases. They occur in two of the three domains of terrestrial life (bacteria, eucarya) and the human genome involves six functional LOX genes, which encode for six different LOX isoforms. One of these isoforms is ALOX15, which has first been described in rabbits in 1974 as enzyme capable of oxidizing membrane phospholipids during the maturational breakdown of mitochondria in immature red blood cells. During the following decades ALOX15 has extensively been characterized and its biological functions have been studied in a number of cellular in vitro systems as well as in various whole animal disease models. This review is aimed at summarizing the current knowledge on the protein-chemical, molecular biological and enzymatic properties of ALOX15 in various species (human, mouse, rabbit, rat) as well as its implication in cellular physiology and in the pathogenesis of various diseases.
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Affiliation(s)
- Igor Ivanov
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Hartmut Kuhn
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Dagmar Heydeck
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
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19
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Horn T, Adel S, Schumann R, Sur S, Kakularam KR, Polamarasetty A, Redanna P, Kuhn H, Heydeck D. Evolutionary aspects of lipoxygenases and genetic diversity of human leukotriene signaling. Prog Lipid Res 2014; 57:13-39. [PMID: 25435097 PMCID: PMC7112624 DOI: 10.1016/j.plipres.2014.11.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 12/14/2022]
Abstract
Leukotrienes are pro-inflammatory lipid mediators, which are biosynthesized via the lipoxygenase pathway of the arachidonic acid cascade. Lipoxygenases form a family of lipid peroxidizing enzymes and human lipoxygenase isoforms have been implicated in the pathogenesis of inflammatory, hyperproliferative (cancer) and neurodegenerative diseases. Lipoxygenases are not restricted to humans but also occur in a large number of pro- and eucaryotic organisms. Lipoxygenase-like sequences have been identified in the three domains of life (bacteria, archaea, eucarya) but because of lacking functional data the occurrence of catalytically active lipoxygenases in archaea still remains an open question. Although the physiological and/or pathophysiological functions of various lipoxygenase isoforms have been studied throughout the last three decades there is no unifying concept for the biological importance of these enzymes. In this review we are summarizing the current knowledge on the distribution of lipoxygenases in living single and multicellular organisms with particular emphasis to higher vertebrates and will also focus on the genetic diversity of enzymes and receptors involved in human leukotriene signaling.
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Affiliation(s)
- Thomas Horn
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany; Department of Chemistry and Biochemistry, University of California - Santa Cruz, 1156 High Street, 95064 Santa Cruz, USA
| | - Susan Adel
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Ralf Schumann
- Institute of Microbiology, Charité - University Medicine Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Saubashya Sur
- Institute of Microbiology, Charité - University Medicine Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Kumar Reddy Kakularam
- Department of Animal Sciences, School of Life Science, University of Hyderabad, Gachibowli, Hyderabad 500046, Telangana, India
| | - Aparoy Polamarasetty
- School of Life Sciences, University of Himachal Pradesh, Dharamshala, Himachal Pradesh 176215, India
| | - Pallu Redanna
- Department of Animal Sciences, School of Life Science, University of Hyderabad, Gachibowli, Hyderabad 500046, Telangana, India; National Institute of Animal Biotechnology, Miyapur, Hyderabad 500049, Telangana, India
| | - Hartmut Kuhn
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Dagmar Heydeck
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
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20
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Kuhn H, Banthiya S, van Leyen K. Mammalian lipoxygenases and their biological relevance. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:308-30. [PMID: 25316652 DOI: 10.1016/j.bbalip.2014.10.002] [Citation(s) in RCA: 409] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/30/2014] [Accepted: 10/03/2014] [Indexed: 02/07/2023]
Abstract
Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
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Affiliation(s)
- Hartmut Kuhn
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Swathi Banthiya
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Klaus van Leyen
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts Genrel Hospital and Harvard Medical School, Charlestown, MA, USA
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21
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Hu S, Sharma SC, Scouras AD, Soudackov A, Carr CAM, Hammes-Schiffer S, Alber T, Klinman JP. Extremely elevated room-temperature kinetic isotope effects quantify the critical role of barrier width in enzymatic C-H activation. J Am Chem Soc 2014; 136:8157-60. [PMID: 24884374 PMCID: PMC4188422 DOI: 10.1021/ja502726s] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Indexed: 01/23/2023]
Abstract
The enzyme soybean lipoxygenase (SLO) has served as a prototype for hydrogen-tunneling reactions, as a result of its unusual kinetic isotope effects (KIEs) and their temperature dependencies. Using a synergy of kinetic, structural, and theoretical studies, we show how the interplay between donor-acceptor distance and active-site flexibility leads to catalytic behavior previously predicted by quantum tunneling theory. Modification of the size of two hydrophobic residues by site-specific mutagenesis in SLO reduces the reaction rate 10(4)-fold and is accompanied by an enormous and unprecedented room-temperature KIE. Fitting of the kinetic data to a non-adiabatic model implicates an expansion of the active site that cannot be compensated by donor-acceptor distance sampling. A 1.7 Å resolution X-ray structure of the double mutant further indicates an unaltered backbone conformation, almost identical side-chain conformations, and a significantly enlarged active-site cavity. These findings show the compelling property of room-temperature hydrogen tunneling within a biological context and demonstrate the very high sensitivity of such tunneling to barrier width.
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Affiliation(s)
- Shenshen Hu
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Sudhir C. Sharma
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Alexander D. Scouras
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Alexander
V. Soudackov
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Cody A. Marcus Carr
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Sharon Hammes-Schiffer
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Tom Alber
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Judith P. Klinman
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
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22
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Muñoz-Garcia A, Thomas CP, Keeney DS, Zheng Y, Brash AR. The importance of the lipoxygenase-hepoxilin pathway in the mammalian epidermal barrier. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1841:401-8. [PMID: 24021977 PMCID: PMC4116325 DOI: 10.1016/j.bbalip.2013.08.020] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/27/2013] [Accepted: 08/30/2013] [Indexed: 01/22/2023]
Abstract
This review covers the background to discovery of the two key lipoxygenases (LOX) involved in epidermal barrier function, 12R-LOX and eLOX3, and our current views on their functioning. In the outer epidermis, their consecutive actions oxidize linoleic acid esterified in ω-hydroxy-ceramide to a hepoxilin-related derivative. The relevant background to hepoxilin and trioxilin biochemistry is briefly reviewed. We outline the evidence that linoleate in the ceramide is the natural substrate of the two LOX enzymes and our proposal for its importance in construction of the epidermal water barrier. Our hypothesis is that the oxidation promotes hydrolysis of the oxidized linoleate moiety from the ceramide. The resulting free ω-hydroxyl of the ω-hydroxyceramide is covalently bound to proteins on the surface of the corneocytes to form the corneocyte lipid envelope, a key barrier component. Understanding the role of the LOX enzymes and their hepoxilin products should provide rational approaches to ameliorative therapy for a number of the congenital ichthyoses involving compromised barrier function. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.
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Affiliation(s)
- Agustí Muñoz-Garcia
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Christopher P Thomas
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Diane S Keeney
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yuxiang Zheng
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alan R Brash
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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23
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Horn T, Reddy Kakularam K, Anton M, Richter C, Reddanna P, Kuhn H. Functional characterization of genetic enzyme variations in human lipoxygenases. Redox Biol 2013; 1:566-77. [PMID: 24282679 PMCID: PMC3840004 DOI: 10.1016/j.redox.2013.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 11/01/2013] [Indexed: 01/09/2023] Open
Abstract
Mammalian lipoxygenases play a role in normal cell development and differentiation but they have also been implicated in the pathogenesis of cardiovascular, hyperproliferative and neurodegenerative diseases. As lipid peroxidizing enzymes they are involved in the regulation of cellular redox homeostasis since they produce lipid hydroperoxides, which serve as an efficient source for free radicals. There are various epidemiological correlation studies relating naturally occurring variations in the six human lipoxygenase genes (SNPs or rare mutations) to the frequency for various diseases in these individuals, but for most of the described variations no functional data are available. Employing a combined bioinformatical and enzymological strategy, which included structural modeling and experimental site-directed mutagenesis, we systematically explored the structural and functional consequences of non-synonymous genetic variations in four different human lipoxygenase genes (ALOX5, ALOX12, ALOX15, and ALOX15B) that have been identified in the human 1000 genome project. Due to a lack of a functional expression system we resigned to analyze the functionality of genetic variations in the hALOX12B and hALOXE3 gene. We found that most of the frequent non-synonymous coding SNPs are located at the enzyme surface and hardly alter the enzyme functionality. In contrast, genetic variations which affect functional important amino acid residues or lead to truncated enzyme variations (nonsense mutations) are usually rare with a global allele frequency<0.1%. This data suggest that there appears to be an evolutionary pressure on the coding regions of the lipoxygenase genes preventing the accumulation of loss-of-function variations in the human population. Non-synonymous coding variations in human lipoxygenases are mostly rare with a global allele frequency <1%. Common ALOX SNPs are mainly localized on the enzyme surface and hardly effect the enzyme functionality. hALOX15B Ala416Asp is a newly discovered loss-of-function mutation in the hALOX gene family while inactivity seems to be caused by severe structural alterations. Our data indicate that there is evolutionary pressure on these redox enzymes preventing the accumulation of loss-of-function variations in the human population. 1000 Genome database is a useful tool to analyze the distribution and functionality of variations in genes of interest.
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Key Words
- 12-H(p)ETE, (5Z,8Z,10E,14Z)-12-hydroperoxyeicosa-5,8,10,14-tetraenoic acid
- 15-H(p)ETE, (5Z,8Z,11Z,13E)-15-hydroperoxyeicosa-5,8,11,13-tetraenoic acid
- 5-H(p)ETE, (6E,8Z,11Z,14Z)-5-hydroperoxyeicosa-6,8,11,14-tetraenoic acid
- 8-H(p)ETE, (5Z,9E,11Z,14Z)-8-hydroperoxyeicosa-5,9,11,14-tetraenoic acid
- ALOX, arachidonate lipoxygenase
- Eicosanoids
- Gene polymorphism
- H(p)ETE, hydroperoxyeicosatetraenoic acid
- HETE, hydroxyeicosatetraenoic acid
- IPTG, Isopropyl-β-D-thiogalactopyranosid
- LOXs, lipoxygenases
- LTA4, 4-[(2S,3S)-3-[(1E,3E,5Z,8Z)-tetradeca-1,3,5,8-tetraen-1-yl]oxiran-2-yl]butanoic acid
- LTB4, 5(S),12(R)-dihydroxy-6,8,10,14-(Z,E,E,Z)-eicosatetraenoic acid
- LTC4, (5S,6R,7E,9E,11Z,14Z)-6-{[(2R)-2-[(4S)-4-amino-4-carboxybutanamido]-2-[(carboxymethyl) carbamoyl]ethyl]sulfanyl}-5-hydroxyeicosa-7,9,11,14-tetraenoic acid
- Leukotrienes
- Lipoxygenases
- SNP
- UTR, untranslated region
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Affiliation(s)
- Thomas Horn
- Institute of Biochemistry, University Medicine Berlin-Charité, Charitéplatz 1, D-10117 Berlin, Germany
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24
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Jin J, Zheng Y, Brash AR. Demonstration of HNE-related aldehyde formation via lipoxygenase-catalyzed synthesis of a bis-allylic dihydroperoxide intermediate. Chem Res Toxicol 2013; 26:896-903. [PMID: 23668325 DOI: 10.1021/tx4000396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
One of the proposed pathways to the synthesis of 4-hydroxy-nonenal (HNE) and related aldehydes entails formation of an intermediate bis-allylic fatty acid dihydroperoxide. As a first direct demonstration of such a pathway and proof of principle, herein we show that 8R-lipoxygenase (8R-LOX) catalyzes the enzymatic production of the HNE-like product (11-oxo-8-hydroperoxy-undeca-5,9-dienoic acid) via synthesis of 8,11-dihydroperoxy-eicosa-5,9,12,14-tetraenoic acid intermediate. Incubation of arachidonic acid with 8R-LOX formed initially 8R-hydroperoxy-eicosatetraenoic acid (8R-HPETE), which was further converted to a mixture of products including a prominent HPNE-like enone. A new bis-allylic dihydroperoxide was trapped when the incubation was repeated on ice. Reincubation of this intermediate with 8R-LOX successfully demonstrated its conversion to the enone products, and this reaction was greatly accelerated by coincubation with NDGA, a reductant of the LOX iron. These findings identify a plausible mechanism that could contribute to the production of 4-hydroxy-alkenals in vivo.
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Affiliation(s)
- Jing Jin
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, USA
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25
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Hoobler EK, Holz C, Holman TR. Pseudoperoxidase investigations of hydroperoxides and inhibitors with human lipoxygenases. Bioorg Med Chem 2013; 21:3894-9. [PMID: 23669189 DOI: 10.1016/j.bmc.2013.04.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/28/2013] [Accepted: 04/03/2013] [Indexed: 01/29/2023]
Abstract
Understanding the mode of action for lipoxygenase (LOX) inhibitors is critical to determining their efficacy in the cell. The pseudoperoxidase assay is an important tool for establishing if a LOX inhibitor is reductive in nature, however, there have been difficulties identifying the proper conditions for each of the many human LOX isozymes. In the current paper, both the 234 nM decomposition (UV) and iron-xylenol orange (XO) assays are shown to be effective methods of detecting pseudoperoxidase activity for 5-LOX, 12-LOX, 15-LOX-1 and 15-LOX-2, but only if 13-(S)-HPODE is used as the hydroperoxide substrate. The AA products, 12-(S)-HPETE and 15-(S)-HPETE, are not consistent hydroperoxide substrates since they undergo a competing transformation to the di-HETE products. Utilizing the above conditions, the selective 12-LOX and 15-LOX-1 inhibitors, probes for diabetes, stroke and asthma, are characterized for their inhibitory nature. Interestingly, ascorbic acid also supports the pseudoperoxidase assay, suggesting that it may have a role in maintaining the inactive ferrous form of LOX in the cell. In addition, it is observed that nordihydroguaiaretic acid (NDGA), a known reductive LOX inhibitor, appears to generate radical species during the pseudoperoxidase assay, which are potent inhibitors against the human LOX isozymes, producing a negative pseudoperoxidase result. Therefore, inhibitors that do not support the pseudoperoxidase assay with the human LOX isozymes, should also be investigated for rapid inactivation, to clarify the negative pseudoperoxidase result.
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Affiliation(s)
- Eric K Hoobler
- Chemistry and Biochemistry Department, University of California, Santa Cruz, CA 95064, USA
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Chaitidis P, Adel S, Anton M, Heydeck D, Kuhn H, Horn T. Lipoxygenase pathways in Homo neanderthalensis: functional comparison with Homo sapiens isoforms. J Lipid Res 2013; 54:1397-409. [PMID: 23475662 DOI: 10.1194/jlr.m035626] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipoxygenases (LOX) have been implicated in biosynthesis of pro- and anti-inflammatory mediators, and a previous report suggested compromised leukotriene signaling in H. neanderthalensis. To search for corresponding differences in leukotriene biosynthesis, we screened the Neandertal genome for LOX genes and found that, as modern humans, this archaic hominid contains six LOX genes (nALOX15, nALOX12, nALOX5, nALOX15B, nALOX12B, and nALOXE3) and one pseudogene. In the Neandertal genome, 60-75% of the amino acids of the different human LOX isoforms have been identified, and the degree of identity varies between 96 and 99%. Most functional amino acids (iron ligands, specificity determinants, calcium and ATP-binding sites, membrane-binding determinants, and phosphorylation sites) are well conserved in the Neandertal LOX isoforms, and expression of selected neandertalized human LOX mutants revealed no major functional defects. However, in nALOX12 and nALOXE3, two premature stop codons were found, leading to inactive enzyme species. These data suggest that ALOX15, ALOX5, ALOX15B, and ALOX12B should have been present as functional enzymes in H. neanderthalensis and that in contrast to lower nonhuman primates (M. mulatta) and other mammals (mice, rats), this ancient hominid expressed a 15-lipoxygenating ALOX15. Expression of ALOXE3 and ALOX12 was compromised, which might have caused problems in epidermal differentiation.
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Affiliation(s)
- Pavlos Chaitidis
- Institute of Biochemistry, University Medicine Berlin - Charité, 10117 Berlin, Germany
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Thomas CP, Boeglin WE, Garcia-Diaz Y, O'Donnell VB, Brash AR. Steric analysis of epoxyalcohol and trihydroxy derivatives of 9-hydroperoxy-linoleic acid from hematin and enzymatic synthesis. Chem Phys Lipids 2013; 167-168:21-32. [PMID: 23352713 DOI: 10.1016/j.chemphyslip.2013.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/06/2012] [Accepted: 01/06/2013] [Indexed: 11/19/2022]
Abstract
We characterize the allylic epoxyalcohols and their trihydroxy hydrolysis products generated from 9R- and 9S-hydroperoxy-octadecenoic acid (HPODE) under non-enzymatic conditions, reaction with hematin and subsequent acid hydrolysis, and enzymatic conditions, incubation with Beta vulgaris containing a hydroperoxide isomerase and epoxide hydrolase. The products were resolved by HPLC and the regio and stereo-chemistry of the transformations were determined through a combination of (1)H NMR and GC-MS analysis of dimethoxypropane derivatives. Four trihydroxy isomers were identified upon mild acid hydrolysis of 9S,10S-trans-epoxy-11E-13S-hydroxyoctadecenoate: 9S,10R,13S, 9S,12R,13S, 9S,10S,13S and 9S,12S,13S-trihydroxy-octadecenoic acids, in the ratio 40:26:22:12. We also identified a prominent δ-ketol rearrangement product from the hydrolysis as mainly the 9-hydroxy-10E-13-oxo isomer. Short incubation (5 min) of 9R- and 9S-HPODE with B. vulgaris extract yielded the 9R- and 9S-hydroxy-10E-12R,13S-cis-epoxy products respectively. Longer incubation (60 min) gave one specific hydrolysis product via epoxide hydrolase, the 9R/S,12S,13S-trihydroxyoctadecenoate. These studies provide a practical approach for the isolation and characterization of allylic epoxy alcohol and trihydroxy products using a combination of HPLC, GC-MS and (1)H NMR.
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Affiliation(s)
- Christopher P Thomas
- Department of Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232-6602, USA
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Wennman A, Oliw EH. Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii. J Lipid Res 2012; 54:762-775. [PMID: 23233731 DOI: 10.1194/jlr.m033787] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mycelium of the rice stem pathogen, Magnaporthe salvinii, secreted linoleate 9S-lipoxygenase (9S-LOX) and epoxy alcohol synthase (EAS). The EAS rapidly transformed 9S-hydroperoxy-octadeca-10E,12Z-dienoic acid (9S-HPODE) to threo 10 (11)-epoxy-9S-hydroxy-12Z-octadecenoic acid, but other hydroperoxy FAs were poor substrates. 9S-LOX was expressed in Pichia pastoris. Recombinant 9S-LOX oxidized 18:2n-6 directly to 9S-HPODE, the end product, and also to two intermediates, 11S-hydroperoxy-9Z,12Z-octadecenoic acid (11S-HPODE; ∼5%) and 13R-hydroperoxy-9Z,11E-octadecadienoic acid (13R-HPODE; ∼1%). 11S- and 13R-HPODE were isomerized to 9S-HPODE, probably after oxidation to peroxyl radicals, β-fragmentation, and oxygen insertion at C-9. The 18:3n-3 was oxidized at C-9, C-11, and C-13, and to 9,16-dihydroxy-10E,12,14E-octadecatrienoic acid. 9S-LOX contained catalytic manganese (Mn:protein ∼0.2:1; Mn/Fe, 1:0.05), and its sequence could be aligned with 77% identity to 13R-LOX with catalytic manganese lipoxygenase (13R-MnLOX) of the Take-all fungus. The Leu350Met mutant of 9S-LOX shifted oxidation of 18:2n-6 from C-9 to C-13, and the Phe347Leu, Phe347Val, and Phe347Ala mutants of 13R-MnLOX from C-13 to C-9. In conclusion, M. salvinii secretes 9S-LOX with catalytic manganese along with a specific EAS. Alterations in the Sloane determinant of 9S-LOX and 13R-MnLOX with larger and smaller hydrophobic residues interconverted the regiospecific oxidation of 18:2n-6, presumably by altering the substrate position in relation to oxygen insertion.
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Affiliation(s)
- Anneli Wennman
- Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, Sweden
| | - Ernst H Oliw
- Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, Sweden
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Joo YC, Oh DK. Lipoxygenases: Potential starting biocatalysts for the synthesis of signaling compounds. Biotechnol Adv 2012; 30:1524-32. [DOI: 10.1016/j.biotechadv.2012.04.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/26/2012] [Accepted: 04/10/2012] [Indexed: 12/11/2022]
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Wennman A, Jernerén F, Hamberg M, Oliw EH. Catalytic convergence of manganese and iron lipoxygenases by replacement of a single amino acid. J Biol Chem 2012; 287:31757-65. [PMID: 22822060 PMCID: PMC3442510 DOI: 10.1074/jbc.m112.364331] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/16/2012] [Indexed: 12/24/2022] Open
Abstract
Lipoxygenases (LOXs) contain a hydrophobic substrate channel with the conserved Gly/Ala determinant of regio- and stereospecificity and a conserved Leu residue near the catalytic non-heme iron. Our goal was to study the importance of this region (Gly(332), Leu(336), and Phe(337)) of a lipoxygenase with catalytic manganese (13R-MnLOX). Recombinant 13R-MnLOX oxidizes 18:2n-6 and 18:3n-3 to 13R-, 11(S or R)-, and 9S-hydroperoxy metabolites (∼80-85, 15-20, and 2-3%, respectively) by suprafacial hydrogen abstraction and oxygenation. Replacement of Phe(337) with Ile changed the stereochemistry of the 13-hydroperoxy metabolites of 18:2n-6 and 18:3n-3 (from ∼100% R to 69-74% S) with little effect on regiospecificity. The abstraction of the pro-S hydrogen of 18:2n-6 was retained, suggesting antarafacial hydrogen abstraction and oxygenation. Replacement of Leu(336) with smaller hydrophobic residues (Val, Ala, and Gly) shifted the oxygenation from C-13 toward C-9 with formation of 9S- and 9R-hydroperoxy metabolites of 18:2n-6 and 18:3n-3. Replacement of Gly(332) and Leu(336) with larger hydrophobic residues (G332A and L336F) selectively augmented dehydration of 13R-hydroperoxyoctadeca-9Z,11E,15Z-trienoic acid and increased the oxidation at C-13 of 18:1n-6. We conclude that hydrophobic replacements of Leu(336) can modify the hydroperoxide configurations at C-9 with little effect on the R configuration at C-13 of the 18:2n-6 and 18:3n-3 metabolites. Replacement of Phe(337) with Ile changed the stereospecific oxidation of 18:2n-6 and 18:3n-3 with formation of 13S-hydroperoxides by hydrogen abstraction and oxygenation in analogy with soybean LOX-1.
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Affiliation(s)
- Anneli Wennman
- From the Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, Sweden and
| | - Fredrik Jernerén
- From the Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, Sweden and
| | - Mats Hamberg
- the Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Solna, Sweden
| | - Ernst H. Oliw
- From the Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, Sweden and
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31
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Järving R, Lõokene A, Kurg R, Siimon L, Järving I, Samel N. Activation of 11R-Lipoxygenase Is Fully Ca2+-Dependent and Controlled by the Phospholipid Composition of the Target Membrane. Biochemistry 2012; 51:3310-20. [DOI: 10.1021/bi201690z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Reet Järving
- Department
of Chemistry, Tallinn University of Technology, Akadeemia tee 15,
12618 Tallinn, Estonia
| | - Aivar Lõokene
- Department
of Chemistry, Tallinn University of Technology, Akadeemia tee 15,
12618 Tallinn, Estonia
| | - Reet Kurg
- Institute of Technology, University of Tartu, Nooruse St 1, 50411 Tartu, Estonia
| | - Liina Siimon
- Department
of Chemistry, Tallinn University of Technology, Akadeemia tee 15,
12618 Tallinn, Estonia
| | - Ivar Järving
- Department
of Chemistry, Tallinn University of Technology, Akadeemia tee 15,
12618 Tallinn, Estonia
| | - Nigulas Samel
- Department
of Chemistry, Tallinn University of Technology, Akadeemia tee 15,
12618 Tallinn, Estonia
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Jin J, Boeglin WE, Cha JK, Brash AR. 8R-Lipoxygenase-catalyzed synthesis of a prominent cis-epoxyalcohol from dihomo-γ-linolenic acid: a distinctive transformation compared with S-lipoxygenases. J Lipid Res 2011; 53:292-9. [PMID: 22158855 DOI: 10.1194/jlr.m022863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conversion of fatty acid hydroperoxides to epoxyalcohols is a well known secondary reaction of lipoxygenases, described for S-specific lipoxygenases forming epoxyalcohols with a trans-epoxide configuration. Here we report on R-specific lipoxygenase synthesis of a cis-epoxyalcohol. Although arachidonic and dihomo-γ-linolenic acids are metabolized by extracts of the Caribbean coral Plexaura homomalla via 8R-lipoxygenase and allene oxide synthase activities, 20:3ω6 forms an additional prominent product, identified using UV, GC-MS, and NMR in comparison to synthetic standards as 8R,9S-cis-epoxy-10S-erythro-hydroxy-eicosa-11Z,14Z-dienoic acid. Both oxygens of (18)O-labeled 8R-hydroperoxide are retained in the product, indicating a hydroperoxide isomerase activity. Recombinant allene oxide synthase formed only allene epoxide from 8R-hydroperoxy-20:3ω6, whereas two different 8R-lipoxygenases selectively produced the epoxyalcohol.A biosynthetic scheme is proposed in which a partial rotation of the reacting intermediate is required to give the observed erythro epoxyalcohol product. This characteristic and the synthesis of cis-epoxy epoxyalcohol may be a feature of R-specific lipoxygenases.
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Affiliation(s)
- Jing Jin
- Department of Pharmacology, and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
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Schurmann K, Anton M, Ivanov I, Richter C, Kuhn H, Walther M. Molecular basis for the reduced catalytic activity of the naturally occurring T560M mutant of human 12/15-lipoxygenase that has been implicated in coronary artery disease. J Biol Chem 2011; 286:23920-7. [PMID: 21558275 DOI: 10.1074/jbc.m110.211821] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Lipoxygenases have been implicated in cardiovascular disease. A rare single-nucleotide polymorphism causing T560M exchange has recently been described, and this mutation leads to a near null variant of the enzyme encoded for by the ALOX15 gene. When we inspected the three-dimensional structure of the rabbit ortholog, we localized Thr-560 outside the active site and identified a hydrogen bridge between its side chain and Gln-294. This interaction is part of a complex hydrogen bond network that appears to be conserved in other mammalian lipoxygenases. Gln-294 and Asn-287 are key amino acids in this network, and we hypothesized that disturbance of this hydrogen bond system causes the low activity of the T560M mutant. To test this hypothesis, we first mutated Thr-560 to amino acids not capable of forming side chain hydrogen bridges (T560M and T560A) and obtained enzyme variants with strongly reduced catalytic activity. In contrast, enzymatic activity was retained after T560S exchange. Enzyme variants with strongly reduced activity were also obtained when we mutated Gln-294 (binding partner of Thr-560) and Asn-287 (binding partner of Gln-294 and Met-418) to Leu. Basic kinetic characterization of the T560M mutant indicated that the enzyme lacks a kinetic lag phase but is rapidly inactivated. These data suggest that the low catalytic efficiency of the naturally occurring T560M mutant is caused by alterations of a hydrogen bond network interconnecting this residue with active site constituents. Disturbance of this bonding network increases the susceptibility of the enzyme for suicidal inactivation.
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Affiliation(s)
- Kathrin Schurmann
- Institute of Biochemistry, University Medicine Berlin-Charité, D-10117 Berlin, Germany
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Zheng Y, Yin H, Boeglin WE, Elias PM, Crumrine D, Beier DR, Brash AR. Lipoxygenases mediate the effect of essential fatty acid in skin barrier formation: a proposed role in releasing omega-hydroxyceramide for construction of the corneocyte lipid envelope. J Biol Chem 2011; 286:24046-56. [PMID: 21558561 DOI: 10.1074/jbc.m111.251496] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A barrier to water loss is vital to maintaining life on dry land. Formation of the mammalian skin barrier requires both the essential fatty acid linoleate and the two lipoxygenases 12R-lipoxygenase (12R-LOX) and epidermal lipoxygenase-3 (eLOX3), although their roles are poorly understood. Linoleate occurs in O-linoleoyl-ω-hydroxyceramide, which, after hydrolysis of the linoleate moiety, is covalently attached to protein via the free ω-hydroxyl of the ceramide, forming the corneocyte lipid envelope, a scaffold between lipid and protein that helps seal the barrier. Here we show using HPLC-UV, LC-MS, GC-MS, and (1)H NMR that O-linoleoyl-ω-hydroxyceramide is oxygenated in a regio- and stereospecific fashion by the consecutive actions of 12R-LOX and eLOX3 and that these products occur naturally in pig and mouse epidermis. 12R-LOX forms 9R-hydroperoxy-linoleoyl-ω-hydroxyceramide, further converted by eLOX3 to specific epoxyalcohol (9R,10R-trans-epoxy-11E-13R-hydroxy) and 9-keto-10E,12Z esters of the ceramide; an epoxy-ketone derivative (9R,10R-trans-epoxy-11E-13-keto) is the most prominent oxidized ceramide in mouse skin. These products are absent in 12R-LOX-deficient mice, which crucially display a near total absence of protein-bound ω-hydroxyceramides and of the corneocyte lipid envelope and die shortly after birth from transepidermal water loss. We conclude that oxygenation of O-linoleoyl-ω-hydroxyceramide is required to facilitate the ester hydrolysis and allow bonding of the ω-hydroxyceramide to protein, providing a coherent explanation for the roles of multiple components in epidermal barrier function. Our study uncovers a hitherto unknown biochemical pathway in which the enzymic oxygenation of ceramides is involved in building a crucial structure of the epidermal barrier.
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Affiliation(s)
- Yuxiang Zheng
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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Zheng Y, Brash AR. Dioxygenase activity of epidermal lipoxygenase-3 unveiled: typical and atypical features of its catalytic activity with natural and synthetic polyunsaturated fatty acids. J Biol Chem 2010; 285:39866-75. [PMID: 20921226 DOI: 10.1074/jbc.m110.155374] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epidermal lipoxygenase-3 (eLOX3) exhibits hydroperoxide isomerase activity implicated in epidermal barrier formation, but its potential dioxygenase activity has remained elusive. We identified herein a synthetic fatty acid, 9E,11Z,14Z-20:3ω6, that was oxygenated by eLOX3 specifically to the 9S-hydroperoxide. Reaction showed a pronounced lag phase, which suggested that eLOX3 is deficient in its activation step. Indeed, we found that high concentrations of hydroperoxide activator (e.g. 65 μM) overcame a prolonged lag phase (>1 h) and unveiled a dioxygenase activity with arachidonic acid; the main products were the 5-, 9-, and 7-hydroperoxyeicosatetraenoic acids (HPETEs). These were R/S mixtures (ranging from ∼50:50 to 73:27), and as the bis-allylic 7-HPETE can be formed only inside the enzyme active site, the results indicate there is oxygen availability along either face of the reacting fatty acid radical. That the active site oxygen supply is limited is implied from the need for continuous re-activation, as carbon radical leakage leaves the enzyme in the unactivated ferrous state. An Ala-to-Gly mutation, known to affect the positioning of O(2) in the active site of other lipoxygenase enzymes, led to more readily activated reaction and a significant increase in the 9R- over the 5-HPETE. Activation and cycling of the ferric enzyme are thus promoted using the 9E,11Z,14Z-20:3ω6 substrate, by continuous hydroperoxide activation, or by the Ala-to-Gly mutation. We suggest that eLOX3 represents one end of a spectrum among lipoxygenases where activation is inefficient, favoring hydroperoxide isomerase cycling, with the opposite end represented by readily activated enzymes in which dioxygenase activity is prominent.
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Affiliation(s)
- Yuxiang Zheng
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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