1
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Patel E, Kumar P, Priyadarshini P, Singla D, Sandhu JS. Molecular docking and dynamic simulation studies of isoflavones inhibiting Lox-2 activity for reducing beany flavor in soybean seeds. J Biomol Struct Dyn 2023:1-10. [PMID: 37902567 DOI: 10.1080/07391102.2023.2275179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 10/20/2023] [Indexed: 10/31/2023]
Abstract
Low-lipoxygenase soybean cultivars are highly desirable because lower lipoxygenase content in soybean seeds leads to better quality soybean-based products and oils that are free from off-flavor or beany flavor. The expression of the Lox-2 gene is mainly responsible for this flavor. Over the years, natural antioxidants have been tested biochemically to inhibit Lox-2 activity, but in-silico studies are still lacking. To investigate the structural basis of inhibition, site-specific docking, as well as molecular dynamics (MD) simulations, were performed. Molecular docking analysis revealed that daidzein and genistein could be effective Lox2 receptor inhibitors. Furthermore, docked complexes were subjected to 100 ns MD simulation studies to analyze the structural conformations and stability of the complex. The analysis demonstrated that daidzein formed a more stable complex with the Lox-2 receptor and showed a higher H-bond propensity with the Asp775 residue. We discovered that the initial conformation of Lox2-daidzein complex changed to a more stable conformation at the beginning of the MD simulation and remained stable until the end with minor fluctuations. Furthermore, our analysis suggested that daidzein acts as a potential Lox-2 inhibitor and is a better candidate compared to genistein, which could be used to solve the beany flavor problem in soybean.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ekta Patel
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India
| | - Pawan Kumar
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India
| | - Pragya Priyadarshini
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India
| | - Deepak Singla
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India
| | - Jagdeep Singh Sandhu
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India
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2
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Noguchi S, Tallman KA, Porter NA, Stec DF, Calcutt MW, Boeglin WE, Brash AR. Evaluation of ω-alkynyl-labeled linoleic and arachidonic acids as substrates for recombinant lipoxygenase pathway enzymes. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159360. [PMID: 37336389 PMCID: PMC10528070 DOI: 10.1016/j.bbalip.2023.159360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/02/2023] [Accepted: 06/11/2023] [Indexed: 06/21/2023]
Abstract
ω-Alkynyl-fatty acids can be used as probes for covalent binding to intracellular macromolecules. To inform future in vivo studies, we determined the rates of reaction of ω-alkynyl-labeled linoleate with recombinant enzymes of the skin 12R-lipoxygenase (12R-LOX) pathway involved in epidermal barrier formation (12R-LOX, epidermal lipoxygenase-3 (eLOX3), and SDR9C7). We also examined the reactivity of ω-alkynyl-arachidonic acid with representative lipoxygenase enzymes employing either "carboxyl end-first" substrate binding (5S-LOX) or "tail-first" (platelet-type 12S-LOX). ω-Alkynyl-linoleic acid was oxygenated by 12R-LOX at 62 ± 9 % of the rate compared to linoleic acid, the alkynyl-9R-HPODE product was isomerized by eLOX3 at only 43 ± 1 % of the natural substrate, whereas its epoxy alcohol product was converted to epoxy ketone linoleic by an NADH-dependent dehydrogenase (SDR9C7) with 91 ± 1 % efficiency. The results suggest the optimal approach will be application of the 12R-LOX/eLOX3-derived epoxyalcohol, which should be most efficiently incorporated into the pathway and allow subsequent analysis of covalent binding to epidermal proteins. Regarding the orientation of substrate binding in LOX catalysis, our results and previous reports suggest the ω-alkynyl group has a stronger inhibitory effect on tail-first binding, as might be expected. Beyond slowing the reaction, however, we found that the tail-first binding and transformation of ω-alkynyl-arachidonic acid by platelet-type 12S-LOX results in almost complete enzyme inactivation, possibly due to reactive intermediates blocking the enzyme active site. Overall, the results reinforce the conclusion that ω-alkynyl-fatty acids are suitable for selected applications after appropriate reactivity is established.
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Affiliation(s)
- Saori Noguchi
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States of America
| | - Keri A Tallman
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, United States of America
| | - Ned A Porter
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, United States of America
| | - Donald F Stec
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, United States of America
| | - M Wade Calcutt
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, United States of America
| | - William E Boeglin
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States of America
| | - Alan R Brash
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States of America.
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3
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Quaranta A, Zöhrer B, Revol-Cavalier J, Benkestock K, Balas L, Oger C, Keyes GS, Wheelock ÅM, Durand T, Galano JM, Ramsden CE, Hamberg M, Wheelock CE. Development of a Chiral Supercritical Fluid Chromatography-Tandem Mass Spectrometry and Reversed-Phase Liquid Chromatography-Tandem Mass Spectrometry Platform for the Quantitative Metabolic Profiling of Octadecanoid Oxylipins. Anal Chem 2022; 94:14618-14626. [PMID: 36219822 PMCID: PMC9607849 DOI: 10.1021/acs.analchem.2c02601] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Octadecanoids are broadly defined as oxylipins (i.e., lipid mediators) derived from 18-carbon fatty acids.
In contrast
to the well-studied eicosanoids, there is a lack of analytical methods
for octadecanoids, hampering further investigations in the field.
We developed an integrated workflow combining chiral separation by
supercritical fluid chromatography (SFC) and reversed-phase liquid
chromatography (LC) coupled to tandem mass spectrometry detection
for quantification of a broad panel of octadecanoids. The platform
includes 70 custom-synthesized analytical and internal standards to
extend the coverage of the octadecanoid synthetic pathways. A total
of 103 octadecanoids could be separated by chiral SFC and complex
enantioseparations could be performed in <13 min, while the achiral
LC method separated 67 octadecanoids in 13.5 min. The LC method provided
a robust complementary approach with greater sensitivity relative
to the SFC method. Both methods were validated in solvent and surrogate
matrix in terms of linearity, lower limits of quantification (LLOQ),
recovery, accuracy, precision, and matrix effects. Instrumental linearity
was good for both methods (R2 > 0.995)
and LLOQ ranged from 0.03 to 6.00 ng/mL for SFC and 0.01 to 1.25 ng/mL
for LC. The average accuracy in the solvent and surrogate matrix ranged
from 89 to 109% in SFC and from 106 to 220% in LC, whereas coefficients
of variation (CV) were <14% (at medium and high concentrations)
and 26% (at low concentrations). Validation in the surrogate matrix
showed negligible matrix effects (<16% for all analytes), and average
recoveries ranged from 71 to 83%. The combined methods provide a platform
to investigate the biological activity of octadecanoids and expand
our understanding of these little-studied compounds.
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Affiliation(s)
- Alessandro Quaranta
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Benedikt Zöhrer
- Department of Respiratory Medicine and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.,Respiratory Medicine Unit, K2 Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Johanna Revol-Cavalier
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden.,Larodan Research Laboratory, Karolinska Institutet, 171 65 Stockholm, Sweden
| | | | - Laurence Balas
- IBMM, Univ Montpellier, CNRS, ENSCM, 34293 Montpellier, France
| | - Camille Oger
- IBMM, Univ Montpellier, CNRS, ENSCM, 34293 Montpellier, France
| | - Gregory S Keyes
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 21224 Baltimore, Maryland, United States
| | - Åsa M Wheelock
- Department of Respiratory Medicine and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.,Respiratory Medicine Unit, K2 Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Thierry Durand
- IBMM, Univ Montpellier, CNRS, ENSCM, 34293 Montpellier, France
| | | | - Christopher E Ramsden
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 21224 Baltimore, Maryland, United States
| | - Mats Hamberg
- Larodan Research Laboratory, Karolinska Institutet, 171 65 Stockholm, Sweden.,Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Craig E Wheelock
- Unit of Integrative Metabolomics, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden.,Department of Respiratory Medicine and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.,Gunma University Initiative for Advanced Research (GIAR), Gunma University, Maebashi, Gunma 371-8511, Japan
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4
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Perry SC, van Hoorebeke C, Sorrentino J, Bautista L, Akinkugbe O, Conrad WS, Rutz N, Holman TR. Structural basis for altered positional specificity of 15-lipoxygenase-1 with 5S-HETE and 7S-HDHA and the implications for the biosynthesis of resolvin E4. Arch Biochem Biophys 2022; 727:109317. [PMID: 35709965 DOI: 10.1016/j.abb.2022.109317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/30/2022] [Accepted: 06/02/2022] [Indexed: 02/04/2023]
Abstract
Human 15-lipoxygenases (LOX) are critical enzymes in the inflammatory process, producing various pro-resolution molecules, such as lipoxins and resolvins, but the exact role each of the two 15-LOXs in these biosynthetic pathways remains elusive. Previously, it was observed that h15-LOX-1 reacted with 5S-HETE in a non-canonical manner, producing primarily the 5S,12S-diHETE product. To determine the active site constraints of h15-LOX-1 in achieving this reactivity, amino acids involved in the fatty acid binding were investigated. It was observed that R402L did not have a large effect on 5S-HETE catalysis, but F414 appeared to π-π stack with 5S-HETE, as seen with AA binding, indicating an aromatic interaction between a double bond of 5S-HETE and F414. Decreasing the size of F352 and I417 shifted oxygenation of 5S-HETE to C12, while increasing the size of these residues reversed the positional specificity of 5S-HETE to C15. Mutants at these locations demonstrated a similar effect with 7S-HDHA as the substrate, indicating that the depth of the active site regulates product specificity for both substrates. Together, these data indicate that of the three regions proposed to control positional specificity, π-π stacking and active site cavity depth are the primary determinants of positional specificity with 5S-HETE and h15-LOX-1. Finally, the altered reactivity of h15-LOX-1 was also observed with 5S-HEPE, producing 5S,12S-diHEPE instead of 5S,15S-diHEPE (aka resolvin E4 (RvE4). However, h15-LOX-2 efficiently produces 5S,15S-diHEPE from 5S-HEPE. This result is important with respect to the biosynthesis of the RvE4 since it obscures which LOX isozyme is involved in its biosynthesis. Future work detailing the expression levels of the lipoxygenase isoforms in immune cells and selective inhibition during the inflammatory response will be required for a comprehensive understanding of RvE4 biosynthesis.
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Affiliation(s)
- Steven C Perry
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | | | - James Sorrentino
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | - Leslie Bautista
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | - Oluwayomi Akinkugbe
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | - William S Conrad
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | - Natalie Rutz
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA
| | - Theodore R Holman
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, USA.
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5
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Kim SE, Lee J, An JU, Kim TH, Oh CW, Ko YJ, Krishnan M, Choi J, Yoon DY, Kim Y, Oh DK. Regioselectivity of an arachidonate 9S-lipoxygenase from Sphingopyxis macrogoltabida that biosynthesizes 9S,15S- and 11S,17S-dihydroxy fatty acids from C20 and C22 polyunsaturated fatty acids. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159091. [PMID: 34902567 DOI: 10.1016/j.bbalip.2021.159091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/14/2021] [Accepted: 12/04/2021] [Indexed: 12/19/2022]
Abstract
Lipoxygenases (LOXs) biosynthesize lipid mediators (LMs) as human signaling molecules. Among LMs, specialized pro-resolving mediators (SPMs) are involved in the resolution of inflammation and infection in humans. Here, the putative LOX from the bacterium Sphingopyxis macrogoltabida was identified as arachidonate 9S-LOX. The enzyme catalyzed oxygenation at the n-12 position of C20 and C22 polyunsaturated fatty acids (PUFAs) to form 9S- and 11S-hydroperoxy fatty acids, which were reduced to 9S- and 11S-hydroxy fatty acids (HFAs) by cysteine, respectively, and it catalyzed again oxygenation at the n-6 position of HFAs to form 9S,15S- and 11S,17S-DiHFAs, respectively. The regioselective residues of 9S-LOX were determined as lle395 and Val569 based on the amino acid alignment and homology models. The regioselectivity of the I395F variant was changed from the n-12 position on C20 PUFA to the n-6 position to form 15S-HFAs. This may be due to the reduction of the substrate-binding pocket by replacing the smaller Ile with a larger Phe. The V569W variant had a significantly lower second‑oxygenating activity compared to wild-type 9S-LOX because the insertion of the hydroxyl group of the first‑oxygenating products at the active site was seemed to be hindered by substituting a larger Trp for a smaller Val. The compounds, 11S-hydroxydocosapentaenoic acid, 9S,15S-dihydroxyeicosatetraenoic acid, 9S,15S-dihydroxyeicosapentaenoic acid, 11S,17S-hydroxydocosapentaenoic acid, and 11S,17S-dihydroxydocosahexaenoic acid, were newly identified by polarimeter, LC-MS/MS, and NMR. 11S,17S-DiHFAs as SPM isomers biosynthesized from C22 PUFAs showed anti-inflammatory activities in mouse and human cells. Our study contributes may stimulate physiological studies by providing new LMs.
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Affiliation(s)
- Seong-Eun Kim
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jin Lee
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jung-Ung An
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Tae-Hun Kim
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Chae-Won Oh
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yoon-Joo Ko
- National Center for Inter-University Research Facilities (NCIRF), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Manigandan Krishnan
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Joonhyeok Choi
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Do-Young Yoon
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yangmee Kim
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Deok-Kun Oh
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
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6
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Veloso C, Videira RA, Andrade PB, Cardoso C, Vitorino C. Topical Fixed-Dose Combinations: Current in vitro methodologies for pre-clinical development. Int J Pharm 2022; 617:121621. [PMID: 35219825 DOI: 10.1016/j.ijpharm.2022.121621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 10/19/2022]
Abstract
The combination of two or more active pharmaceutical ingredients in the same dosage form - fixed-dose combination products - for topical administration represents a promising therapeutic approach for treating several pathologies, including pain. The pre-clinical development of fixed-dose combination products aims to characterize the interactions between the different APIs and ensure that the final medicinal product has the required safety characteristics. To this end, there are several regulatory accepted in vitro tests to assess the safety of medicinal products intended for cutaneous administration. In turn, the evaluation of anti-inflammatory activity should be based on models described in the scientific literature, as there are no models fully validated by competent entities. Therefore, the present work presents the information regarding accepted in vitro tests to assess the safety of topical products and the most used methods to assess anti-inflammatory activity. Additionally, a new approach to select a fixed-dose combination product with the potential to enhance the therapeutic effects of the individual active pharmaceutical ingredients is rationalized by integrating the overall effects on several targets relevant for inflammation and pain management in one numeric index.
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Affiliation(s)
- Cláudia Veloso
- Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Coimbra Chemistry Center, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
| | - Romeu A Videira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal.
| | - Paula B Andrade
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Catarina Cardoso
- Laboratórios Basi, Parque Industrial Manuel Lourenço Ferreira, lote 15, 3450-232 Mortágua, Portugal
| | - Carla Vitorino
- Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Coimbra Chemistry Center, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal.
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7
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Chen D, Xiao Z, Guo H, Gogishvili D, Setroikromo R, Wouden PE, Dekker FJ. Identification of a Bromodomain‐like Region in 15‐Lipoxygenase‐1 Explains Its Nuclear Localization. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Deng Chen
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Zhangping Xiao
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Hao Guo
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Dea Gogishvili
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Rita Setroikromo
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Petra E. Wouden
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Frank J. Dekker
- Department Chemical and Pharmaceutical Biology Groningen Research Institute of Pharmacy (GRIP) University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
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8
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Chen D, Xiao Z, Guo H, Gogishvili D, Setroikromo R, van der Wouden PE, Dekker FJ. Identification of a Bromodomain-like Region in 15-Lipoxygenase-1 Explains Its Nuclear Localization. Angew Chem Int Ed Engl 2021; 60:21875-21883. [PMID: 34388301 PMCID: PMC8518382 DOI: 10.1002/anie.202106968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Indexed: 01/17/2023]
Abstract
Lipoxygenase (LOX) activity provides oxidative lipid metabolites, which are involved in inflammatory disorders and tumorigenesis. Activity-based probes to detect the activity of LOX enzymes in their cellular context provide opportunities to explore LOX biology and LOX inhibition. Here, we developed Labelox B as a potent covalent LOX inhibitor for one-step activity-based labeling of proteins with LOX activity. Labelox B was used to establish an ELISA-based assay for affinity capture and antibody-based detection of specific LOX isoenzymes. Moreover, Labelox B enabled efficient activity-based labeling of endogenous LOXs in living cells. LOX proved to localize in the nucleus, which was rationalized by identification of a functional bromodomain-like consensus motif in 15-LOX-1. This indicates that 15-LOX-1 is not only involved in oxidative lipid metabolism, but also in chromatin binding, which suggests a potential role in chromatin modifications.
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Affiliation(s)
- Deng Chen
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Zhangping Xiao
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Hao Guo
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Dea Gogishvili
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Rita Setroikromo
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Petra E van der Wouden
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
| | - Frank J Dekker
- Department Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Antonius Deusinglaan 1, 9713, AV, Groningen, The Netherlands
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9
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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: 6] [Impact Index Per Article: 1.5] [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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10
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Perry SC, Kalyanaraman C, Tourdot BE, Conrad WS, Akinkugbe O, Freedman JC, Holinstat M, Jacobson MP, Holman TR. 15-Lipoxygenase-1 biosynthesis of 7S,14S-diHDHA implicates 15-lipoxygenase-2 in biosynthesis of resolvin D5. J Lipid Res 2020; 61:1087-1103. [PMID: 32404334 PMCID: PMC7328043 DOI: 10.1194/jlr.ra120000777] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/08/2020] [Indexed: 12/15/2022] Open
Abstract
The two oxylipins 7S,14S-dihydroxydocosahexaenoic acid (diHDHA) and 7S,17S-diHDHA [resolvin D5 (RvD5)] have been found in macrophages and infectious inflammatory exudates and are believed to function as specialized pro-resolving mediators (SPMs). Their biosynthesis is thought to proceed through sequential oxidations of DHA by lipoxygenase (LOX) enzymes, specifically, by human 5-LOX (h5-LOX) first to 7(S)-hydroxy-4Z,8E,10Z,13Z,16Z,19Z-DHA (7S-HDHA), followed by human platelet 12-LOX (h12-LOX) to form 7(S),14(S)-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-DHA (7S,14S-diHDHA) or human reticulocyte 15-LOX-1 (h15-LOX-1) to form RvD5. In this work, we determined that oxidation of 7(S)-hydroperoxy-4Z,8E,10Z,13Z,16Z,19Z-DHA to 7S,14S-diHDHA is performed with similar kinetics by either h12-LOX or h15-LOX-1. The oxidation at C14 of DHA by h12-LOX was expected, but the noncanonical reaction of h15-LOX-1 to make over 80% 7S,14S-diHDHA was larger than expected. Results of computer modeling suggested that the alcohol on C7 of 7S-HDHA hydrogen bonds with the backbone carbonyl of Ile399, forcing the hydrogen abstraction from C12 to oxygenate on C14 but not C17. This result raised questions regarding the synthesis of RvD5. Strikingly, we found that h15-LOX-2 oxygenates 7S-HDHA almost exclusively at C17, forming RvD5 with faster kinetics than does h15-LOX-1. The presence of h15-LOX-2 in neutrophils and macrophages suggests that it may have a greater role in biosynthesizing SPMs than previously thought. We also determined that the reactions of h5-LOX with 14(S)-hydroperoxy-4Z,7Z,10Z,12E,16Z,19Z-DHA and 17(S)-hydroperoxy-4Z,7Z,10Z,13Z,15E,19Z-DHA are kinetically slow compared with DHA, suggesting that these reactions may be minor biosynthetic routes in vivo. Additionally, we show that 7S,14S-diHDHA and RvD5 have anti-aggregation properties with platelets at low micromolar potencies, which could directly regulate clot resolution.
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Affiliation(s)
- Steven C Perry
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Chakrapani Kalyanaraman
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, CA 94143
| | - Benjamin E Tourdot
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - William S Conrad
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Oluwayomi Akinkugbe
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - John Cody Freedman
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Michael Holinstat
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, CA 94143
| | - Theodore R Holman
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064. mailto:
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Multiple Roles of Diatom-Derived Oxylipins within Marine Environments and Their Potential Biotechnological Applications. Mar Drugs 2020; 18:md18070342. [PMID: 32629777 PMCID: PMC7401250 DOI: 10.3390/md18070342] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023] Open
Abstract
The chemical ecology of marine diatoms has been the subject of several studies in the last decades, due to the discovery of oxylipins with multiple simultaneous functions including roles in chemical defence (antipredator, allelopathic and antibacterial compounds) and/or cell-to-cell signalling. Diatoms represent a fundamental compartment of marine ecosystems because they contribute to about 45% of global primary production even if they represent only 1% of the Earth’s photosynthetic biomass. The discovery that they produce several toxic metabolites deriving from the oxidation of polyunsaturated fatty acids, known as oxylipins, has changed our perspectives about secondary metabolites shaping plant–plant and plant–animal interactions in the oceans. More recently, their possible biotechnological potential has been evaluated, with promising results on their potential as anticancer compounds. Here, we focus on some recent findings in this field obtained in the last decade, investigating the role of diatom oxylipins in cell-to-cell communication and their negative impact on marine biota. Moreover, we also explore and discuss the possible biotechnological applications of diatom oxylipins.
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Djian B, Hornung E, Ischebeck T, Feussner I. The green microalga Lobosphaera incisa harbours an arachidonate 15S-lipoxygenase. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21 Suppl 1:131-142. [PMID: 30277010 PMCID: PMC6587457 DOI: 10.1111/plb.12920] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
The green microalga Lobosphaera incisa is an oleaginous eukaryotic alga that is rich in arachidonic acid (20:4). Being rich in this polyunsaturated fatty acid (PUFA), however, makes it sensitive to oxidation. In plants, lipoxygenases (LOXs) are the major enzymes that oxidise these molecules. Here, we describe, to our best knowledge, the first characterisation of a cDNA encoding a LOX (LiLOX) from a green alga. To obtain first insights into its function, we expressed it in E. coli, purified the recombinant enzyme and analysed its enzyme activity. The protein sequence suggests that LiLOX and plastidic LOXs from bryophytes and flowering plants may share a common ancestor. The fact that LiLOX oxidises all PUFAs tested with a consistent oxidation on the carbon n-6, suggests that PUFAs enter the substrate channel through their methyl group first (tail first). Additionally, LiLOX form the fatty acid hydroperoxide in strict S configuration. LiLOX may represent a good model to study plastid LOX, because it is stable after heterologous expression in E. coli and highly active in vitro. Moreover, as the first characterised LOX from green microalgae, it opens the possibility to study endogenous LOX pathways in these organisms.
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Affiliation(s)
- B. Djian
- Department of Plant BiochemistryUniversity of GoettingenAlbrecht‐von‐Haller‐Institute for Plant SciencesGoettingenGermany
| | - E. Hornung
- Department of Plant BiochemistryUniversity of GoettingenAlbrecht‐von‐Haller‐Institute for Plant SciencesGoettingenGermany
| | - T. Ischebeck
- Department of Plant BiochemistryUniversity of GoettingenAlbrecht‐von‐Haller‐Institute for Plant SciencesGoettingenGermany
- Goettingen Metabolomics and Lipidomics LaboratoryUniversity of GoettingenGoettingen Center for Molecular Biosciences (GZMB)GoettingenGermany
| | - I. Feussner
- Department of Plant BiochemistryUniversity of GoettingenAlbrecht‐von‐Haller‐Institute for Plant SciencesGoettingenGermany
- Goettingen Metabolomics and Lipidomics LaboratoryUniversity of GoettingenGoettingen Center for Molecular Biosciences (GZMB)GoettingenGermany
- Department of Plant BiochemistryUniversity of GoettingenGoettingen Center for Molecular Biosciences (GZMB)GoettingenGermany
- Department of Plant BiochemistryUniversity of GoettingenInternational Center for Advanced Studies of Energy Conversion (ICASEC)GoettingenGermany
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Green AR, Freedman C, Tena J, Tourdot BE, Liu B, Holinstat M, Holman TR. 5 S,15 S-Dihydroperoxyeicosatetraenoic Acid (5,15-diHpETE) as a Lipoxin Intermediate: Reactivity and Kinetics with Human Leukocyte 5-Lipoxygenase, Platelet 12-Lipoxygenase, and Reticulocyte 15-Lipoxygenase-1. Biochemistry 2018; 57:6726-6734. [PMID: 30407793 DOI: 10.1021/acs.biochem.8b00889] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of 5 S,15 S-dihydroperoxyeicosatetraenoic acid (5,15-diHpETE) with human 5-lipoxygenase (LOX), human platelet 12-LOX, and human reticulocyte 15-LOX-1 was investigated to determine the reactivity and relative rates of producing lipoxins (LXs). 5-LOX does not react with 5,15-diHpETE, although it can produce LXA4 when 15-HpETE is the substrate. In contrast, both 12-LOX and 15-LOX-1 react with 5,15-diHpETE, forming specifically LXB4. For 12-LOX and 5,15-diHpETE, the kinetic parameters are kcat = 0.17 s-1 and kcat/ KM = 0.011 μM-1 s-1 [106- and 1600-fold lower than those for 12-LOX oxygenation of arachidonic acid (AA), respectively]. On the other hand, for 15-LOX-1 the equivalent parameters are kcat = 4.6 s-1 and kcat/ KM = 0.21 μM-1 s-1 (3-fold higher and similar to those for 12-HpETE formation by 15-LOX-1 from AA, respectively). This contrasts with the complete lack of reaction of 15-LOX-2 with 5,15-diHpETE [Green, A. R., et al. (2016) Biochemistry 55, 2832-2840]. Our data indicate that 12-LOX is markedly inferior to 15-LOX-1 in catalyzing the production of LXB4 from 5,15-diHpETE. Platelet aggregation was inhibited by the addition of 5,15-diHpETE, with an IC50 of 1.3 μM; however, LXB4 did not significantly inhibit collagen-mediated platelet activation up to 10 μM. In summary, LXB4 is the primary product of 12-LOX and 15-LOX-1 catalysis, if 5,15-diHpETE is the substrate, with 15-LOX-1 being 20-fold more efficient than 12-LOX. LXA4 is the primary product with 5-LOX but only if 15-HpETE is the substrate. Approximately equal proportions of LXA4 and LXB4 are produced by 12-LOX but only if LTA4 is the substrate, as described previously [Sheppard, K. A., et al. (1992) Biochim. Biophys. Acta 1133, 223-234].
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Affiliation(s)
- Abigail R Green
- Department of Chemistry and Biochemistry , University of California, Santa Cruz , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Cody Freedman
- Department of Chemistry and Biochemistry , University of California, Santa Cruz , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Jennyfer Tena
- Department of Chemistry and Biochemistry , University of California, Santa Cruz , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Benjamin E Tourdot
- Department of Pharmacology , University of Michigan , 500 South State Street , Ann Arbor , Michigan 48109 , United States
| | - Benjamin Liu
- Department of Chemistry and Biochemistry , University of California, Santa Cruz , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Michael Holinstat
- Department of Pharmacology , University of Michigan , 500 South State Street , Ann Arbor , Michigan 48109 , United States
| | - Theodore R Holman
- Department of Chemistry and Biochemistry , University of California, Santa Cruz , 1156 High Street , Santa Cruz , California 95064 , United States
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Regiospecificity of a novel bacterial lipoxygenase from Myxococcus xanthus for polyunsaturated fatty acids. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:823-833. [DOI: 10.1016/j.bbalip.2018.04.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/13/2018] [Accepted: 04/18/2018] [Indexed: 11/17/2022]
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15
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Tirapegui C, Acevedo-Fuentes W, Dahech P, Torrent C, Barrias P, Rojas-Poblete M, Mascayano C. Easy and rapid preparation of benzoylhydrazides and their diazene derivatives as inhibitors of 15-lipoxygenase. Bioorg Med Chem Lett 2017; 27:1649-1653. [PMID: 28318946 DOI: 10.1016/j.bmcl.2017.03.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/05/2017] [Accepted: 03/06/2017] [Indexed: 11/28/2022]
Abstract
Two series of diaza derivatives were prepared by solvent-free condensation of benzoic acid and 4-substituted phenylhydrazines in order to obtain phenylhydrazides (HYD series) and, by oxidation of these compounds, the corresponding benzoyldiazenes (DIA series). Both sets were evaluated as inhibitors of soybean 15-lipoxygenase activity and antioxidant capability in the FRAP and CUPRAC assays. The most potent inhibitors of both series exhibited IC50 values in the low micromolar range. Kinetic studies showed that at least the more active compounds were competitive inhibitors. Docking results indicated that the most potent inhibitor interacts strongly with Ile-839 and iron in the active site.
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Affiliation(s)
- Cristian Tirapegui
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile; Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, correo 33, Santiago, Chile.
| | - Williams Acevedo-Fuentes
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - Pablo Dahech
- Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, correo 33, Santiago, Chile
| | - Claudia Torrent
- Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, correo 33, Santiago, Chile
| | - Pablo Barrias
- Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, correo 33, Santiago, Chile
| | - Macarena Rojas-Poblete
- Relativistic Molecular Physics (ReMoPh) Group, Ph.D. Program in Molecular, Physical Chemistry, Universidad Andrés Bello, Av. República 275, Santiago 8370146, Chile; Universidad Tecnológica de Chile INACAP, Chile
| | - Carolina Mascayano
- Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, correo 33, Santiago, Chile
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16
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Sacharzewska E, Bielecki P, Bernatowicz P, Niklinski J, Kowal-Bielecka O, Kowal K. The role of 12/15-lipoxygenase in production of selected eicosanoids in allergic airway inflammation. Adv Med Sci 2016; 61:141-6. [PMID: 26686860 DOI: 10.1016/j.advms.2015.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 12/14/2022]
Abstract
PURPOSE To evaluate the role of 12/15-lipoxygenase (LOX) in regulation of synthesis of selected eicosanoids in mice sensitized and challenged with Dermatophagoides pteronyssinus (Dp) allergen extract. MATERIALS AND METHODS Both C57Bl and 12/15-LOX knockout mice were sensitized by 2 intraperitoneal injections and subsequently challenged by inhalation with Dp allergen extract. Sham sensitized and challenged mice were used as controls. Samples of bronchoalveolar lavage (BAL) were used for assessment of prostaglandin E2 (PGE2), cysteinyl leukotreienes (cysLT), lipoxin A4 (LXA4) and 15-hydroxyeicosatetraenoic acid (15-HETE) concentration using ELISA method. Whole lung samples were used for isolation of RNA and evaluation of selected genes involved in eicosanoid metabolism, including cyclooxygenase-2 (COX-2), 12/15-LOX, 5-LOX and 5-LOX activated protein (FLAP). RESULTS Allergen-induced airway inflammation was associated with significant (9-fold, 95% CI 8.068-9.932-fold; p<0.05) up-regulation of 12/15-LOX in wild type but not in the 12/15-LOX knockout mice in which 12/15-LOX mRNA remained undetectable. Lack of 12/15-LOX was associated with significant attenuation of production of 15-HETE in response to allergen challenge. On the contrary, the greatest up-regulation of COX-2 after allergen exposure was demonstrated in the 12/15-LOX knockout mice (4.3-fold vs sham group) and was significantly greater than in the wild type counterparts (5.185-fold, 95% CI 4.723-6.309-fold; p<0.05 vs wild type mice). Also, allergen challenged 12/15-LOX knockout mice were characterized by greater production of PGE2 and cysLT. CONCLUSION The 12/15-LOX plays an important role in the metabolism of eicosanoids in response to allergen-induced airway inflammation.
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Saura P, Maréchal JD, Masgrau L, Lluch JM, González-Lafont À. Computational insight into the catalytic implication of head/tail-first orientation of arachidonic acid in human 5-lipoxygenase: consequences for the positional specificity of oxygenation. Phys Chem Chem Phys 2016; 18:23017-35. [DOI: 10.1039/c6cp03973a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Using a multi-scale approach to search for the arachidonic acid binding modes that determine the catalytic specificity of human 5-LOX.
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Affiliation(s)
- Patricia Saura
- Departament de Química
- Universitat Autonòma de Barcelona
- 08193 Bellaterra
- Spain
- Institut de Biotecnologia i de Biomedicina (IBB)
| | | | - Laura Masgrau
- Institut de Biotecnologia i de Biomedicina (IBB)
- Universitat Autonòma de Barcelona
- 08193 Bellaterra
- Spain
| | - José M. Lluch
- Departament de Química
- Universitat Autonòma de Barcelona
- 08193 Bellaterra
- Spain
- Institut de Biotecnologia i de Biomedicina (IBB)
| | - Àngels González-Lafont
- Departament de Química
- Universitat Autonòma de Barcelona
- 08193 Bellaterra
- Spain
- Institut de Biotecnologia i de Biomedicina (IBB)
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18
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Rothe T, Gruber F, Uderhardt S, Ipseiz N, Rössner S, Oskolkova O, Blüml S, Leitinger N, Bicker W, Bochkov VN, Yamamoto M, Steinkasserer A, Schett G, Zinser E, Krönke G. 12/15-Lipoxygenase-mediated enzymatic lipid oxidation regulates DC maturation and function. J Clin Invest 2015; 125:1944-54. [PMID: 25844901 DOI: 10.1172/jci78490] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 02/27/2015] [Indexed: 11/17/2022] Open
Abstract
DCs are able to undergo rapid maturation, which subsequently allows them to initiate and orchestrate T cell-driven immune responses. DC maturation must be tightly controlled in order to avoid random T cell activation and development of autoimmunity. Here, we determined that 12/15-lipoxygenase-meditated (12/15-LO-mediated) enzymatic lipid oxidation regulates DC activation and fine-tunes consecutive T cell responses. Specifically, 12/15-LO activity determined the DC activation threshold via generation of phospholipid oxidation products that induced an antioxidative response dependent on the transcription factor NRF2. Deletion of the 12/15-LO-encoding gene or pharmacologic inhibition of 12/15-LO in murine or human DCs accelerated maturation and shifted the cytokine profile, thereby favoring the differentiation of Th17 cells. Exposure of 12/15-LO-deficient DCs to 12/15-LO-derived oxidized phospholipids attenuated both DC activation and the development of Th17 cells. Analysis of lymphatic tissues from 12/15-LO-deficient mice confirmed enhanced maturation of DCs as well as an increased differentiation of Th17 cells. Moreover, experimental autoimmune encephalomyelitis in mice lacking 12/15-LO resulted in an exacerbated Th17-driven autoimmune disease. Together, our data reveal that 12/15-LO controls maturation of DCs and implicate enzymatic lipid oxidation in shaping the adaptive immune response.
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Hadjipavlou-Litina D, Pontiki E. Aryl-acetic and cinnamic acids as lipoxygenase inhibitors with antioxidant, anti-inflammatory, and anticancer activity. Methods Mol Biol 2015; 1208:361-77. [PMID: 25323520 DOI: 10.1007/978-1-4939-1441-8_26] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cinnamic acids have been identified as interesting compounds with cytotoxic, anti-inflammatory, and antioxidant properties. Lipoxygenase pathway, catalyzing the first two steps of the transformation of arachidonic acid into leukotrienes is implicated in several processes such as cell differentiation, inflammation and carcinogenesis. Development of drugs that interfere with the formation or effects of these metabolites would be important for the treatment of various diseases like asthma, psoriasis, ulcerative colitis, rheumatoid arthritis, atherosclerosis, cancer, and blood vessel disorders. Till now, asthma consists of the only pathological case in which improvement has been shown by lipoxygenase LO inhibitors. Thus, the research has been directed towards the development of drugs that interfere with the formation of leukotrienes. In order to explore the anti-inflammatory and cytotoxic effects of antioxidant acrylic/cinnamic acids a series of derivatives bearing the appropriate moieties have been synthesized via the Knoevenagel condensation and evaluated for their biological activities. The compounds have shown important antioxidant activity, anti-inflammatory activity and very good inhibition of soybean lipoxygenase while some of them were tested for their anticancer activity.
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Affiliation(s)
- Dimitra Hadjipavlou-Litina
- Department of Pharmaceutical Chemistry, School of Pharmacy, Aristotle University of Thessaloniki, University Campus, Thessaloniki, 54124, Greece,
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20
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Yang Y, Wong SE, Lightstone FC. Understanding a substrate's product regioselectivity in a family of enzymes: a case study of acetaminophen binding in cytochrome P450s. PLoS One 2014; 9:e87058. [PMID: 24498291 PMCID: PMC3911926 DOI: 10.1371/journal.pone.0087058] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 12/17/2013] [Indexed: 11/19/2022] Open
Abstract
Product regioselectivity as influenced by molecular recognition is a key aspect of enzyme catalysis. We applied large-scale two-dimensional (2D) umbrella sampling (USP) simulations to characterize acetaminophen (APAP) binding in the active sites of the family of Cytochrome P450 (CYP) enzymes as a case study to show the different regioselectivity exhibited by a single substrate in comparative enzymes. Our results successfully explain the experimentally observed product regioselectivity for all five human CYPs included in this study, demonstrating that binding events play an important role in determining regioselectivity. In CYP2C9 and CYP3A4, weak interactions in an overall large active site cavity result in a fairly small binding free energy difference between APAP reactive binding states, consistent with experimental results that show little preference for resulting metabolites. In contrast, in CYP1A2 and CYP2E1, APAP is strongly restrained by a compact binding pocket, leading to a preferred binding conformation. The calculated binding equilibrium of APAP within the compact active site of CYP2A6 is able to predict the experimentally documented product ratios and is also applied to explain APAP regioselectivity in CYP1A2 and CYP2C9. APAP regioselectivity seems to be related to the selectivity for one binding conformation over another binding conformation as dictated by the size and shape of the active site. Additionally, unlike docking and molecular dynamics (MD), our free energy calculations successfully reproduced a unique APAP pose in CYP3A4 that had been reported experimentally, suggesting this approach is well suited to find the realistic binding pose and the lowest-energy starting structure for studying the chemical reaction step in the future.
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Affiliation(s)
- Yue Yang
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Sergio E. Wong
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Felice C. Lightstone
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California, United States of America
- * E-mail:
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Bushnell EAC, Jamil R, Gauld JW. Gaining insight into the chemistry of lipoxygenases: a computational investigation into the catalytic mechanism of (8R)-lipoxygenase. J Biol Inorg Chem 2013; 18:343-55. [PMID: 23361122 DOI: 10.1007/s00775-013-0978-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
Abstract
Lipoxygenases (LOXs) are ubiquitous in nature and catalyze a range of life-essential reactions within organisms. In particular they are critical to the formation of eicosanoids, which are critical for normal cell function. However, a number of important questions about the reactivity and mechanism of these enzymes still remain. Specifically, although the initial step in the mechanism of LOXs has been well studied, little is known of subsequent steps. Thus, with use of a quantum mechanical/molecular mechanical approach, the complete catalytic mechanism of (8R)-LOX was investigated. The results have provided a better understanding of the general chemistry of LOXs as a whole. In particular, from comparisons with soybean LOX-1, it appears that the initial proton-coupled electron transfer may be very similar among all LOXs. Furthermore, LOXs appear to undergo multistate reactivity where potential spin inversion of an electron may occur either in the attack of O(2) or in the regeneration of the active site. Lastly, it is shown that with the explicit modeling of the environment, the regeneration of the active center likely occurs via the rotation of the intermediate followed by an outer-sphere [Formula: see text] transfer as opposed to the formation of a "purple intermediate" complex.
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Affiliation(s)
- Eric A C Bushnell
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, N9B 3P4, Canada
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Moin ST, Hofer TS, Sattar R, Ul-Haq Z. Molecular dynamics simulation of mammalian 15S-lipoxygenase with AMBER force field. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2011; 40:715-26. [PMID: 21360129 DOI: 10.1007/s00249-011-0684-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 11/28/2010] [Accepted: 02/04/2011] [Indexed: 01/09/2023]
Abstract
A molecular dynamics simulation study of mononuclear iron 15S-lipoxygenase (15S-LOX) from rabbit reticulocytes was performed to investigate its structure and dynamics; newly developed AMBER force field parameters were employed for the first coordination sphere of the catalytic iron (II). The results obtained from this study demonstrate that the structural features of the catalytic iron coordination site are in good agreement with available data obtained from experiments. The motional flexibility of the N-terminal β-barrel domain is greater than the C-terminal catalytic domain; flexibility was assessed in terms of B-factors and secondary structure calculations. The significant features obtained for the relative motional flexibility of these two domains of 15S-LOX in solution as well as the isolated C-terminal domain were analyzed in terms of radius of gyration and maximum diameter, which correlated well with the structural flexibility of 15-lipoxygenase-1 in solution as probed by small-angle X-ray scattering. The motional flexibility indicates interdomain motion between the N-terminal β-barrel and the C-terminal catalytic domain; this was further verified by the evaluation of central bending in the solvated LOX molecule, which identified an unstructured stretch of amino acids as the interdomain linker. The average bending angle confirmed significant central bending between these two domains, which was linked to the high degree of motional freedom of the N-terminal β-barrel domain in aqueous solutions. This can be considered to have biological relevance for membrane binding as well as for regulating the catalytic domain.
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Affiliation(s)
- Syed Tarique Moin
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
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23
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Toledo L, Masgrau L, Maréchal JD, Lluch JM, González-Lafont À. Insights into the Mechanism of Binding of Arachidonic Acid to Mammalian 15-Lipoxygenases. J Phys Chem B 2010; 114:7037-46. [DOI: 10.1021/jp912120n] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lea Toledo
- Departament de Química and Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Laura Masgrau
- Departament de Química and Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Jean-Didier Maréchal
- Departament de Química and Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - José M. Lluch
- Departament de Química and Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Àngels González-Lafont
- Departament de Química and Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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24
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Abstract
The identification of nitric oxide ((*)NO) as an endogenously produced free radical mediator of endothelial-dependent relaxation and host defense has fundamentally changed concepts of cell signal transduction. Ligand-receptor oriented paradigms of cell signaling were originally centered on the concept of a high affinity and specific interaction between a ligand and its receptor, resulting in the activation of secondary signaling events such as gene expression or modulation of catalytic protein function. While (*)NO ligation of the heme iron of soluble guanylate cyclase is consistent with this perspective, the readily diffusible and broadly reactive (*)NO is increasingly appreciated to react with a vast array of target molecules that mediate paracrine vasodilator actions, inhibition of thrombosis and neointimal proliferation, and both pro- and antiinflammatory signaling reactions that are not affected by inhibitors of soluble guanylate cyclase. There is an expanding array of functionally significant "off target" collateral reactions mediated by (*)NO that are guanylate cyclase-independent and rather are dictated by anatomic distribution and the formation of secondary (*)NO-derived species. These reactions are a critical element of redox-regulated signaling and are addressed herein in the context of the oxidation of unsaturated fatty acids to vascular and inflammatory signaling mediators. Because of their abundance and the intrinsic reactivity of unsaturated lipid intermediates and eicosanoid metabolism enzymes with (*)NO and other oxides of nitrogen, lipid signaling mechanisms are a significant target for regulation by (*)NO in the vascular compartment. This convergence of (*)NO and lipid signaling pathways thus adds another level of regulation to physiological responses such as vasodilation, thrombosis, and inflammation. Herein, interactions between (*)NO and lipid signaling events are placed in the context of cardiovascular regulation.
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Affiliation(s)
- Volker Rudolph
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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25
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Neau DB, Gilbert NC, Bartlett SEG, Boeglin W, Brash AR, Newcomer ME. The 1.85 A structure of an 8R-lipoxygenase suggests a general model for lipoxygenase product specificity. Biochemistry 2009; 48:7906-15. [PMID: 19594169 PMCID: PMC4715880 DOI: 10.1021/bi900084m] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lipoxygenases (LOX) play pivotal roles in the biosynthesis of leukotrienes and other biologically active eicosanoids derived from arachidonic acid. A mechanistic understanding of substrate recognition, when lipoxygenases that recognize the same substrate generate different products, can be used to help guide the design of enzyme-specific inhibitors. We report here the 1.85 A resolution structure of an 8R-lipoxygenase from Plexaura homomalla, an enzyme with a sequence approximately 40% identical to that of human 5-LOX. The structure reveals a U-shaped channel, defined by invariant amino acids, that would allow substrate access to the catalytic iron. We demonstrate that mutations within the channel significantly impact enzyme activity and propose a novel model for substrate binding potentially applicable to other members of this enzyme family.
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Affiliation(s)
- David B. Neau
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Nathaniel C. Gilbert
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Su e G. Bartlett
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - William Boeglin
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Alan R. Brash
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Marcia E. Newcomer
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803,Author to whom correspondence should be addressed: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, Tel : (225)578-7383, Fax: (225)578-7258,
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26
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Wecksler AT, Jacquot C, van der Donk WA, Holman TR. Mechanistic investigations of human reticulocyte 15- and platelet 12-lipoxygenases with arachidonic acid. Biochemistry 2009; 48:6259-67. [PMID: 19469483 DOI: 10.1021/bi802332j] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human reticulocyte 15-lipoxygenase-1 (15-hLO-1) and human platelet 12-lipoxygenase (12-hLO) have been implicated in a number of diseases, with differences in their relative activity potentially playing a central role. In this work, we characterize the catalytic mechanism of these two enzymes with arachidonic acid (AA) as the substrate. Using variable-temperature kinetic isotope effects (KIE) and solvent isotope effects (SIE), we demonstrate that both k(cat)/K(M) and k(cat) for 15-hLO-1 and 12-hLO involve multiple rate-limiting steps that include a solvent-dependent step and hydrogen atom abstraction. A relatively low k(cat)/K(M) KIE of 8 was determined for 15-hLO-1, which increases to 18 upon the addition of the allosteric effector molecule, 12-hydroxyeicosatetraenoic acid (12-HETE), indicating a tunneling mechanism. Furthermore, the addition of 12-HETE lowers the observed k(cat)/K(M) SIE from 2.2 to 1.4, indicating that the rate-limiting contribution from a solvent sensitive step in the reaction mechanism of 15-hLO-1 has decreased, with a concomitant increase in the C-H bond abstraction contribution. Finally, the allosteric binding of 12-HETE to 15-hLO-1 decreases the K(M)[O(2)] for AA to 15 microM but increases the K(M)[O(2)] for linoleic acid (LA) to 22 microM, such that the k(cat)/K(M)[O(2)] values become similar for both substrates (approximately 0.3 s(-1) microM(-1)). Considering that the oxygen concentration in cancerous tissue can be less than 5 microM, this result may have cellular implications with respect to the substrate specificity of 15-hLO-1.
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Affiliation(s)
- Aaron T Wecksler
- Chemistry and Biochemistry Department, University of California, Santa Cruz, California 95064, USA
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27
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Jacquot C, McGinley CM, Plata E, Holman TR, van der Donk WA. Synthesis of 11-thialinoleic acid and 14-thialinoleic acid, inhibitors of soybean and human lipoxygenases. Org Biomol Chem 2008; 6:4242-52. [PMID: 18972057 PMCID: PMC2883171 DOI: 10.1039/b808003h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lipoxygenases catalyse the oxidation of polyunsaturated fatty acids and have been invoked in many diseases including cancer, atherosclerosis and Alzheimer's disease. Currently, no X-ray structures are available with substrate or substrate analogues bound in a productive conformation. Such structures would be very useful for examining interactions between substrate and active site residues. Reported here are the syntheses of linoleic acid analogues containing a sulfur atom at the 11 or 14 positions. The key steps in the syntheses were the incorporation of sulfur using nucleophilic attack of metallated alkynes on electrophilic sulfur compounds and the subsequent stereospecific tantalum-mediated reduction of the alkynylsulfide to the cis-alkenylsulfide. Kinetic assays performed with soybean lipoxygenase-1 showed that both 11-thialinoleic acid and 14-thialinoleic acid were competitive inhibitors with respect to linoleic acid with K(i) values of 22 and 35 microM, respectively. On the other hand, 11-thialinoleic acid was a noncompetitive inhibitor with respect to arachidonic acid with K(is) and K(ii) values of 48 and 36 microM, respectively. 11-Thialinoleic acid was also a noncompetitive inhibitor of human 15-lipoxygenase-1 with arachidonic acid (K(is) = 11.4 microM, K(ii) = 18.1 microM) or linoleic acid as substrate (K(is) = 20.1 microM, K(ii) = 20.0 microM), and a competitive inhibitor of human 12-lipoxygenase with arachidonic acid as substrate (K(i) = 2.5 microM). The presence of inhibitor did not change the regioselectivity of soybean lipoxygenase-1, human 12- or 15-lipoxygenase-1.
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Affiliation(s)
- Cyril Jacquot
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801. Fax: (217) 244-8533; Tel: (217) 244-5360;
| | - Chris M. McGinley
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801. Fax: (217) 244-8533; Tel: (217) 244-5360;
| | - Erik Plata
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801. Fax: (217) 244-8533; Tel: (217) 244-5360;
| | - Theodore R. Holman
- Chemistry and Biochemistry Department, University of California, Santa Cruz, Santa Cruz, CA 95064. Fax: (831) 459-2935; Tel: (831) 459-5884;
| | - Wilfred A. van der Donk
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801. Fax: (217) 244-8533; Tel: (217) 244-5360;
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28
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Jacquot C, Wecksler AT, McGinley CM, Segraves EN, Holman TR, van der Donk WA. Isotope sensitive branching and kinetic isotope effects in the reaction of deuterated arachidonic acids with human 12- and 15-lipoxygenases. Biochemistry 2008; 47:7295-303. [PMID: 18547056 DOI: 10.1021/bi800308q] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Lipoxygenases (LOs) catalyze lipid peroxidation and have been implicated in a number of human diseases connected to oxidative stress and inflammation. These enzymes have also attracted considerable attention due to large kinetic isotope effects (30-80) for the rate-limiting hydrogen abstraction step with linoleic acid (LA) as substrate. Herein, we report kinetic isotope effects (KIEs) in the reactions of three human LOs (platelet 12-hLO, reticulocyte 15-hLO-1, and epithelial 15-hLO-2) with arachidonic acid (AA). Surprisingly, the observed KIEs with AA were much smaller than the previously reported values with LA. Investigation into the origins for the smaller KIEs led to the discovery of isotope sensitive branching of the reaction pathways. Product distribution analysis demonstrated an inversion in the regioselectivity of 15-hLO-1, with hydrogen abstraction from C13 being the major pathway with unlabeled AA but abstraction from C10 predominating when the methylene group at position 13 was deuterated. Smaller but clear changes in regioselectivity were also observed for 12-hLO and 15-hLO-2.
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Affiliation(s)
- Cyril Jacquot
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
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29
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Choi J, Chon JK, Kim S, Shin W. Conformational flexibility in mammalian 15S-lipoxygenase: Reinterpretation of the crystallographic data. Proteins 2008; 70:1023-32. [PMID: 17847087 DOI: 10.1002/prot.21590] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lipoxygenases (LOXs) are a family of nonheme iron dioxygenases that catalyze the regioselective and stereospecific hydroperoxidation of polyunsaturated fatty acids, and are involved in a variety of inflammatory diseases and cancers. The crystal structure of rabbit 15S-LOX1 that was reported by Gillmor et al. in 1997 has played key roles for understanding the properties of mammalian LOXs. In this structure, three segments, including 12 residues in the superficial alpha2 helix, are absent and have usually been described as "disordered." By reinterpreting the original crystallographic data we were able to elucidate two different conformations of the molecule, both having well ordered alpha2 helices. Surprisingly, one molecule contained an inhibitor and the other did not, thereby adopting a closed and an open form, respectively. They differed in the conformation of the segments that were absent in the original structure, which is highlighted by a 12 A movement of alpha2. Consequently, they showed a difference in the size and shape of the substrate-binding cavity. The new model should provide new insight into the catalytic mechanism involving induced conformational change of the binding pocket. It may also be helpful for the structure-based design of LOX inhibitors.
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Affiliation(s)
- Jongkeun Choi
- Department of Chemistry, Seoul National University, Seoul, Korea
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30
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A near null variant of 12/15-LOX encoded by a novel SNP in ALOX15 and the risk of coronary artery disease. Atherosclerosis 2007; 198:136-44. [PMID: 17959182 DOI: 10.1016/j.atherosclerosis.2007.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Revised: 07/11/2007] [Accepted: 09/04/2007] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Murine genetic models suggest that function of the 12/15-LOX enzyme promotes atherosclerosis. We tested the hypothesis that exonic and/or promoter single nucleotide polymorphisms (SNPs) in the human 12/15-LOX gene (ALOX15) alter the risk of symptomatic coronary artery disease (CAD). METHODS AND RESULTS We resequenced ALOX15 and then genotyped a common promoter and a less common novel coding SNP (T560M) in 1809 subjects with CAD and 1734 controls from Kaiser Permanente including a subset of participants of the Coronary Artery Risk Development in Young Adults study. We found no association between the promoter SNP and the risk of CAD. However, heterozygote carriers of the 560M allele had an increased risk of CAD (adjusted OR, 1.62; P=0.02) compared to non-carriers. In vitro studies demonstrated a 20-fold reduction in the catalytic activity of 560M when compared to 560T. We then genotyped T560M in 12,974 participants of the Atherosclerosis Risk in Communities study and similarly found that heterozygote carriers had an increased risk of CAD compared to non-carriers (adjusted HR, 1.31; P=0.06). In both population studies, homozygote carriers were rare and associated with a non-significant decreased risk of CAD compared to non-carriers (adjusted OR, 0.55; P=0.63 and HR, 0.93; P=0.9). CONCLUSIONS A coding SNP in ALOX15 (T560M) results in a near null variant of human 12/15-LOX. Assuming a co-dominant mode of inheritance, this variant does not protect against CAD. Assuming a recessive mode of inheritance, the effect of this mutation remains unclear, but is unlikely to provide a protective effect to the degree suggested by mouse knockout studies.
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31
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Vasquez-Martinez Y, Ohri RV, Kenyon V, Holman TR, Sepúlveda-Boza S. Structure-activity relationship studies of flavonoids as potent inhibitors of human platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2. Bioorg Med Chem 2007; 15:7408-25. [PMID: 17869117 PMCID: PMC2117341 DOI: 10.1016/j.bmc.2007.07.036] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 07/11/2007] [Accepted: 07/13/2007] [Indexed: 11/25/2022]
Abstract
Human lipoxygenase (hLO) isozymes have been implicated in a number of disease states and have attracted much attention with respect to their inhibition. One class of inhibitors, the flavonoids, have been shown to be potent lipoxygenase inhibitors but their study has been restricted to those compounds found in nature, which have limited structural variability. We have therefore carried out a comprehensive study to determine the structural requirements for flavonoid potency and selectivity against platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2. We conclude from this study that catechols are essential for high potency, that isoflavones and isoflavonones tend to select against 12-hLO, that isoflavons tend to select against 15-hLO-1, but few flavonoids target 15-hLO-2.
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Affiliation(s)
- Yesseny Vasquez-Martinez
- Laboratorio de Investigación Científica Emory Black, Escuela de Medicina, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Casilla 442, Correo 2 Santiago, Chile
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32
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Jang S, Huon T, Kim K, Um E, Han O. Regiochemical and Stereochemical Evidence for Enzyme-Initiated Catalysis in Dual Positional Specific Maize Lipoxygenase-1. Org Lett 2007; 9:3113-6. [PMID: 17629290 DOI: 10.1021/ol0712024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dual positional specific maize lipoxygenase-1 catalyzed the formation of racemic mixtures of four possible regioisomers and was strongly inhibited by the radical scavenger, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoxy radical. Molecular modeling studies indicated that the oxygen-binding cavity is segregated from the substrate-binding cavity. The data suggest that a bis-allylic radical reaction intermediate is generated enzymatically, released from the enzyme active site, and subsequently oxygenated outside of the enzyme active site by a nonenzymatic mechanism.
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Affiliation(s)
- Sungkuk Jang
- Department of Molecular Biotechnology, Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Kwangju 500-757, Republic of Korea
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33
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Koukoulitsa C, Hadjipavlou-Litina D, Geromichalos GD, Skaltsa H. Inhibitory effect on soybean lipoxygenase and docking studies of some secondary metabolites, isolated from Origanum vulgare L. ssp. hirtum. J Enzyme Inhib Med Chem 2007; 22:99-104. [PMID: 17373554 DOI: 10.1080/14756360600991017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
In this study, five secondary metabolites (caffeic acid, rosmarinic acid, lithospermic acid B, 12-hydroxyjasmonic acid 12-O-beta-glucoside and p-menth-3-ene-1,2-diol 1-O-beta-glucopyranoside) isolated from the polar extracts of the plant Origanum vulgare L. ssp. hirtum, were tested in vitro for their ability to inhibit soybean lipoxygenase. Among the examined compounds, lithospermic acid B demonstrated the best inhibitory activity on soybean lipoxygenase with IC50 = 0.1 mM. Docking studies have been undertaken as an attempt for better understanding the interactions of these compounds within the active site of soybean lipoxygenase. The predicted binding energy values correlated well with the observed biological data.
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Affiliation(s)
- Catherine Koukoulitsa
- Department of Pharmacognosy and Chemistry of Natural Products, School of Pharmacy, University of Athens, Panepistimiopolis, Zografou, Athens, Greece.
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34
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Cristea M, Oliw EH. On the singular, dual, and multiple positional specificity of manganese lipoxygenase and its G316A mutant. J Lipid Res 2007; 48:890-903. [PMID: 17259599 DOI: 10.1194/jlr.m600505-jlr200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract manganese lipoxygenase (Mn-LO) oxygenates 18:3n-3 and 18:2n-6 to bis-allylic 11S-hydroperoxy fatty acids, which are converted to 13R-hydroperoxy fatty acids. Other unsaturated C(16)-C(22) fatty acids, except 17:3n-3, are poor substrates, possibly because of ineffective enzyme activation (Mn(II)-->Mn(III)) by the produced hydroperoxides. Our aim was to determine whether unsaturated C(16)-C(22) fatty acids were oxidized by Mn(III)-LO. Mn(III)-LO oxidized C(16), C(19), C(20), and C(22) n-3 and n-6 fatty acids. The carbon chain length influenced the position of hydrogen abstraction (n-8, n-5) and oxygen insertion at the terminal or the penultimate 1Z,4Z-pentadienes. Dilinoleoyl-glycerophosphatidylcholine was oxidized by Mn-LO, in agreement with a "tail-first" model. 16:3n-3 was oxidized at the bis-allylic n-5 carbon and at positions n-3, n-7, and n-6. Long fatty acids, 19:3n-3, 20:3n-3, 20:4n-6, 22:5n-3, and 22:5n-6, were oxidized mainly at the n-6 and the bis-allylic n-8 positions (in ratios of approximately 3:2). The bis-allylic hydroperoxides accumulated with one exception, 13-hydroperoxyeicosatetraenoic acid (13-HPETE). Mn(III)-LO oxidized 20:4n-6 to 15R-HPETE ( approximately 60%) and 13-HPETE ( approximately 37%) and converted 13-HPETE to 15R-HPETE. Mn(III)-LO G316A oxygenated mainly 16:3n-3 at positions n-7 and n-6, 19:3n-3 at n-10, n-8, and n-6, and 20:3n-3 at n-10 and n-8. We conclude that Mn-LO likely binds fatty acids tail-first and oxygenates many C(16), C(18), C(20), and C(22) fatty acids to significant amounts of bis-allylic hydroperoxides.
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Affiliation(s)
- Mirela Cristea
- Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University Biomedical Center, SE-751 24 Uppsala, Sweden
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35
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Liu W, Wang LH, Fabian P, Hayashi Y, McGinley CM, van der Donk WA, Kulmacz RJ. Arabidopsis thaliana fatty acid alpha-dioxygenase-1: evaluation of substrates, inhibitors and amino-terminal function. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2006; 44:284-93. [PMID: 16889973 DOI: 10.1016/j.plaphy.2006.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Indexed: 05/11/2023]
Abstract
Plant alpha dioxygenases (PADOX) convert fatty acids to 2-hydroperoxy products that are important in plant signaling pathways. The PADOX amino-terminal domain is distinct from that in other myeloperoxidase-family hemoproteins, and the positional specificity and prosthetic group of PADOX distinguish them from the non-heme iron plant lipoxygenases. The constraints of the PADOX active site on potential substrates are poorly understood and only limited structure-function and mechanistic information is available for these enzymes. We developed several bacterial and insect cell systems for expression of recombinant Arabidopsis thaliana PADOX1 and evaluated the enzyme's substrate and inhibitor profiles and explored the functional role of the amino-terminal domain. Substrate specificity studies gave the following relative oxygenase activity values: linolenate, 1.00; linoleate, 0.95; oleate, 0.84; palmitoleate, 0.69; myristate, 0.23; palmitate, 0.17; and gamma-linolenate, 0.16. Methyl esters of myristate, linoleate and linolenate were not oxygenated. 3-Thiamyristate was the only oxygenase substrate that produced pronounced enzyme self-inactivation during catalysis. 3,4-Dehydromyristate inactivated the oxygenase without appreciable oxygen consumption. Several compounds inhibited oxygenase activity, including catechol (K(i) approximately 90 microM), divalent zinc ion (K(i) approximately 50 microM), N,N,N',N'-tetramethyl-p-phenylenediamine (K(i) approximately 20 microM) and cyanide ion (K(i) approximately 5 microM). Zinc ion did not change the K(m) values for linoleate or oxygen, or the K(i) value for cyanide, indicating that zinc acts at a distinct site from the other compounds. Gel-filtration chromatography revealed considerable variation in oligomeric state of recombinant PADOX1 produced in the various expression systems, but oligomeric state was not correlated with activity. Deletion of the first eight or fourteen PADOX1 residues in a NuSA-PADOX1 fusion protein led to 13 and 83% decreases in activity, respectively, indicating the N-terminal region is important for normal catalytic activity.
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Affiliation(s)
- W Liu
- Department of Internal Medicine, University of Texas Health Science Center at Houston, MSB 5.284, 6431 Fannin Street, TX 77030, USA
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Lloyd T, Krol A, Campanaro D, Malkowski M. Purification, crystallization and preliminary X-ray diffraction analysis of pathogen-inducible oxygenase (PIOX) from Oryza sativa. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:365-7. [PMID: 16582486 PMCID: PMC2222573 DOI: 10.1107/s1744309106007305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2006] [Accepted: 02/28/2006] [Indexed: 05/08/2023]
Abstract
Pathogen-inducible oxygenase (PIOX) is a heme-containing membrane-associated protein found in monocotyledon and dicotyledon plants that utilizes molecular oxygen to convert polyunsaturated fatty acids into their corresponding 2R-hydroperoxides. PIOX is a member of a larger family of fatty-acid alpha-dioxygenases that includes the mammalian cyclooxygenase enzymes cyclooxygenase 1 and 2 (COX-1 and COX-2). Single crystals of PIOX from rice (Oryza sativa) have been grown from MPD using recombinant protein expressed in Escherichia coli and subsequently extracted utilizing decyl maltoside as the solubilizing detergent. Crystals diffract to 3.0 angstroms resolution using a rotating-anode generator and R-AXIS IV detector, and belong to space group P1. Based on the Matthews coefficient and self-rotation function analyses, there are presumed to be four molecules in the asymmetric unit related by noncrystallographic 222 symmetry.
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Affiliation(s)
- Tracy Lloyd
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
| | - Adam Krol
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
| | - Danielle Campanaro
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
- Department of Structural Biology, SUNY at Buffalo, Buffalo, New York 14203, USA
| | - Michael Malkowski
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
- Department of Structural Biology, SUNY at Buffalo, Buffalo, New York 14203, USA
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37
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Kühn H, O'Donnell VB. Inflammation and immune regulation by 12/15-lipoxygenases. Prog Lipid Res 2006; 45:334-56. [PMID: 16678271 DOI: 10.1016/j.plipres.2006.02.003] [Citation(s) in RCA: 296] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 01/19/2006] [Accepted: 02/06/2006] [Indexed: 12/22/2022]
Abstract
12/15-Lipoxygenases (12/15-LOX) are members of the LOX family, which are expressed in mammals by monocytes and macrophages following induction by the T helper type 2 cytokines, interleukins-4 and -13. They oxygenate free polyenoic fatty acids but also ester lipids and even complex lipid-protein assemblies such as biomembranes and lipoproteins. The primary oxidation products are either reduced by glutathione peroxidases to corresponding hydroxy derivatives or metabolized into secondary oxidized lipids including leukotrienes, lipoxins and hepoxilins, which act as lipid mediators. Examination of knockout and transgenic animals revealed important roles for 12/15-LOX in inflammatory diseases, including atherosclerosis, cancer, osteoporosis, angiotension II-dependent hypertension and diabetes. In vitro studies suggested 12/15-LOX products as coactivators of peroxisomal proliferator activating-receptors (PPAR), regulators of cytokine generation, and modulators of gene expression related to inflammation resolution. Despite much work in this area, the biochemical mechanisms by which 12/15-LOX regulates physiological and pathological immune cell function are not fully understood. This review will summarize the biochemistry and tissue expression of 12/15-LOX and will describe the current knowledge regarding its immunobiology and regulation of inflammation.
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Affiliation(s)
- Hartmut Kühn
- Institute of Biochemistry, Monbijoustrasse 2, University Medicine Berlin -- Charité, Germany
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Charlier C, Hénichart JP, Durant F, Wouters J. Structural insights into human 5-lipoxygenase inhibition: combined ligand-based and target-based approach. J Med Chem 2006; 49:186-95. [PMID: 16392803 DOI: 10.1021/jm050870x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The human 5-LOX enzyme and its interaction with competitive inhibitors were investigated by means of a combined ligand-based and target-based approach. First, a pharmacophore model was generated for 16 non redox 5-LOX inhibitors with Catalyst (HipHop module). It includes two hydrophobic groups, an aromatic ring, and two hydrogen bond acceptors. The 3D structure of human 5-LOX was then modeled based on the crystal structure of rabbit 15-LOX, and the binding modes of representative ligands were studied by molecular docking. Confrontation of the docking results with the pharmacophore model allowed the weighting of the pharmacophoric features and the integration of structural information. This led to the proposal of an interaction model inside the 5-LOX active site, consisting of four major and two secondary interaction points: on one hand, two hydrophobic groups, an aromatic ring, and a hydrogen bond acceptor, and, on the other hand, an acidic moiety and an additional hydrogen bond acceptor.
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Affiliation(s)
- Caroline Charlier
- Laboratory of Structural Biological Chemistry, University of Namur, FUNDP, 61, rue de Bruxelles, B-5000 Namur, Belgium
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Mortimer M, Järving R, Brash AR, Samel N, Järving I. Identification and characterization of an arachidonate 11R-lipoxygenase. Arch Biochem Biophys 2006; 445:147-55. [PMID: 16321357 DOI: 10.1016/j.abb.2005.10.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/22/2005] [Accepted: 10/28/2005] [Indexed: 11/16/2022]
Abstract
11R-Lipoxygenase (11R-LOX) activity has been detected in several marine invertebrates, and here we report the first cloning and expression of the enzyme. The cDNA encoding a protein of 77kDa was isolated by RT-PCR from the soft coral Gersemia fruticosa and expressed in Escherichia coli. Incubations of recombinant enzyme with arachidonic acid yielded a single product, identified by RP-HPLC, GC-MS, and chiral phase-HPLC as 11R-hydroperoxyeicosatetraenoic acid. Other C18, C20, and C22 substrates are also oxygenated, preferentially at the omega10 position. Significantly, both Ca(2+)-ions and a membrane fraction are required for catalytic activity. Calcium effects translocation of the soluble 11R-LOX to the membrane and this association is reversible by Ca(2+) chelation. The enzyme sequence contains some conserved amino acids implicated in calcium activation of mammalian 5-LOX, and with its obligate requirement for membrane interaction the 11R-LOX may thus provide a new model for further analysis of this aspect of lipoxygenase activation.
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Affiliation(s)
- Monika Mortimer
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
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40
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Kuhn H, Saam J, Eibach S, Holzhütter HG, Ivanov I, Walther M. Structural biology of mammalian lipoxygenases: Enzymatic consequences of targeted alterations of the protein structure. Biochem Biophys Res Commun 2005; 338:93-101. [PMID: 16168952 DOI: 10.1016/j.bbrc.2005.08.238] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Accepted: 08/27/2005] [Indexed: 11/19/2022]
Abstract
Lipoxygenases form a heterogeneous family of lipid peroxidizing enzymes, which have been implicated in the pathogenesis of diseases with major health political relevance (bronchial asthma, atherosclerosis, cancer, and osteoporosis). The crystal structures of one mammalian lipoxygenase and of two plant isoenzymes have been solved and the structural bases of important enzyme properties (reaction specificity, membrane binding, and suicidal inactivation) have been investigated in the past. This review will briefly summarize our current understanding on the structural biology of the most important mammalian lipoxygenase isoforms and will also address selected mechanistic features of the lipoxygenase reaction.
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Affiliation(s)
- Hartmut Kuhn
- Institute of Biochemistry, University Medicine Berlin-Charite, Monbijoustr. 2, 10117 Berlin, Germany.
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41
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Abstract
Lipoxygenases (LOXs) form a heterogeneous family of lipid-peroxidizing enzymes, and several LOX-isoforms (12/15-LOX, 5-LOX) have been implicated in atherogenesis. However, the precise role of these enzymes is still a matter of discussion. 12/15-LOXs are capable of oxidizing lipoproteins (low-density lipoprotein (LDL), high-density lipoprotein (HDL)) to atherogenic forms, and functional inactivation of this enzyme in murine atherosclerosis models slows down lesion formation. In contrast, rabbits that overexpress this enzyme were protected from lesion formation when fed a lipid-rich diet. To contribute to this discussion, we recently investigated the impact of 12/15-LOX overexpression on in vitro foam cell formation. When 12/15-LOX-transfected J774 cells were incubated in culture with modified LDL, we found that intracellular lipid deposition was reduced in the transfected cells when compared with the corresponding control transfectants. This paper briefly summarizes the current status of knowledge on the biological activity of different LOX-isoforms in atherogenesis and will also provide novel experimental data characterizing the role of 12/15-LOX in cellular LDL modification and for in vitro foam cell formation.
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Affiliation(s)
- Hartmut Kühn
- Institute of Biochemistry, University Medicine Berlin, Berlin, Germany.
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Meruvu S, Walther M, Ivanov I, Hammarström S, Fürstenberger G, Krieg P, Reddanna P, Kuhn H. Sequence determinants for the reaction specificity of murine (12R)-lipoxygenase: targeted substrate modification and site-directed mutagenesis. J Biol Chem 2005; 280:36633-41. [PMID: 16129665 DOI: 10.1074/jbc.m508260200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mammalian lipoxygenases (LOXs) are categorized with respect to their positional specificity of arachidonic acid oxygenation. Site-directed mutagenesis identified sequence determinants for the positional specificity of these enzymes, and a critical amino acid for the stereoselectivity was recently discovered. To search for sequence determinants of murine (12R)-LOX, we carried out multiple amino acid sequence alignments and found that Phe(390), Gly(441), Ala(455), and Val(631) align with previously identified positional determinants of S-LOX isoforms. Multiple site-directed mutagenesis studies on Phe(390) and Ala(455) did not induce specific alterations in the reaction specificity, but yielded enzyme species with reduced specific activities and stereo random product patterns. Mutation of Gly(441) to Ala, which caused drastic alterations in the reaction specificity of other LOX isoforms, failed to induce major alterations in the positional specificity of mouse (12R)-LOX, but markedly modified the enantioselectivity of the enzyme. When Val(631), which aligns with the positional determinant Ile(593) of rabbit 15-LOX, was mutated to a less space-filling residue (Ala or Gly), we obtained an enzyme species with augmented catalytic activity and specifically altered reaction characteristics (major formation of chiral (11R)-hydroxyeicosatetraenoic acid methyl ester). The importance of Val(631) for the stereo control of murine (12R)-LOX was confirmed with other substrates such as methyl linoleate and 20-hydroxyeicosatetraenoic acid methyl ester. These data identify Val(631) as the major sequence determinant for the specificity of murine (12R)-LOX. Furthermore, we conclude that substrate fatty acids may adopt different catalytically productive arrangements at the active site of murine (12R)-LOX and that each of these arrangements may lead to the formation of chiral oxygenation products.
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Affiliation(s)
- Sunitha Meruvu
- University Medicine Berlin Charité, Monbijoustrasse 2, 10117 Berlin, Germany
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Coffa G, Schneider C, Brash AR. A comprehensive model of positional and stereo control in lipoxygenases. Biochem Biophys Res Commun 2005; 338:87-92. [PMID: 16111652 DOI: 10.1016/j.bbrc.2005.07.185] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Accepted: 07/30/2005] [Indexed: 11/19/2022]
Abstract
The lipoxygenase gene family can synthesize an array of chiral hydroperoxy derivatives from polyunsaturated fatty acids. An individual enzyme, however, reacts molecular oxygen on a single position on the carbon chain and in a single stereo configuration. Regiospecificity is regulated by the orientation and depth of substrate entry into the active site. Stereospecificity is a different issue and only recently has experimental support emerged to explain the conceptual basis of stereo control. A key determinant is a single active site residue conserved as an Ala in S lipoxygenases and a Gly in R lipoxygenases; this residue controls R or S stereochemistry by switching the position of oxygenation on the reacting pentadiene of the substrate. In this review, we meld together the factors that control product regio- and stereochemistry into a general model that can account for the specificity of individual lipoxygenase reactions.
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Affiliation(s)
- Gianguido Coffa
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Cai K, Fang Y, Xia YM, Su YF. Effect of exogenous iron on aerobic catalytic mechanism of soybean lipoxygenase. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2004.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Coffa G, Brash AR. A single active site residue directs oxygenation stereospecificity in lipoxygenases: stereocontrol is linked to the position of oxygenation. Proc Natl Acad Sci U S A 2004; 101:15579-84. [PMID: 15496467 PMCID: PMC524819 DOI: 10.1073/pnas.0406727101] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lipoxygenases are a class of dioxygenases that form hydroperoxy fatty acids with distinct positional and stereo configurations. Several amino acid residues influencing regiospecificity have been identified, whereas the basis of stereocontrol is not understood. We have now identified a single residue in the lipoxygenase catalytic domain that is important for stereocontrol; it is conserved as an Ala in S lipoxygenases and a Gly in R lipoxygenases. Our results with mutation of the conserved Ala to Gly in two S lipoxygenases (mouse 8S-LOX and human 15-LOX-2) and the corresponding Gly-Ala substitution in two R lipoxygenases (human 12R-LOX and coral 8R-LOX) reveal that the basis for R or S stereo-control also involves a switch in the position of oxygenation on the substrate. After the initial hydrogen abstraction, antarafacial oxygenation at one end or the other of the activated pair of double bonds (pentadiene) gives, for example, 8S or 12R product. The Ala residue promotes oxygenation on the reactive pentadiene at the end deep in the substrate binding pocket and S stereochemistry of the product hydroperoxide, and a Gly residue promotes oxygenation at the proximal end of the reactive pentadiene resulting in R stereochemistry. A model of lipoxygenase reaction specificity is proposed in which product regiochemistry and stereochemistry are determined by fixed relationships between substrate orientation, hydrogen abstraction, and the Gly or Ala residue we have identified.
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Affiliation(s)
- Gianguido Coffa
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Bannenberg GL, Aliberti J, Hong S, Sher A, Serhan C. Exogenous pathogen and plant 15-lipoxygenase initiate endogenous lipoxin A4 biosynthesis. J Exp Med 2004; 199:515-23. [PMID: 14970178 PMCID: PMC2211821 DOI: 10.1084/jem.20031325] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Accepted: 12/03/2003] [Indexed: 12/03/2022] Open
Abstract
Lipoxin A4 (LXA4) is a potent endogenous lipoxygenase-derived eicosanoid with antiinflammatory and proresolving properties. Supraphysiological levels of LXA4 are generated during infection by Toxoplasma gondii, which in turn reduces interleukin (IL) 12 production by dendritic cells, thus dampening Th1-type cell-mediated immune responses and host immunopathology. In the present work, we sought evidence for the structural basis of T. gondii's ability to activate LXA4 biosynthesis. Proteomic analysis of T. gondii extract (soluble tachyzoite antigen [STAg]), which preserves the immunosuppressive and antiinflammatory activity of the parasite, yielded several peptide matches to known plant lipoxygenases. Hence, we incubated STAg itself with arachidonic acid and found using LC-UV-MS-MS-based lipidomics that STAg produced both 15-HETE and 5,15-diHETE, indicating that T. gondii carries 15-lipoxygenase activity. In addition, T. gondii tachyzoites (the rapidly multiplying and invasive stage of the parasite) generated LXA4 when provided with arachidonic acid. Local administration of a plant (soybean) lipoxygenase itself reduced neutrophilic infiltration in murine peritonitis, demonstrating that 15-lipoxygenase possesses antiinflammatory properties. Administration of plant 15-lipoxygenase generated endogenous LXA4 and mimicked the suppression of IL-12 production by splenic dendritic cells observed after T. gondii infection or STAg administration. Together, these results indicate that 15-lipoxygenase expressed by a pathogen as well as exogenously administered 15-lipoxygenase can interact with host biosynthetic circuits for endogenous "stop signals" that divert the host immune response and limit acute inflammation.
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Affiliation(s)
- Gerard L Bannenberg
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Charlier C, Michaux C. Dual inhibition of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) as a new strategy to provide safer non-steroidal anti-inflammatory drugs. Eur J Med Chem 2003; 38:645-59. [PMID: 12932896 DOI: 10.1016/s0223-5234(03)00115-6] [Citation(s) in RCA: 301] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dual COX/5-LOX (cyclooxygenase/5-lipoxygenase) inhibitors constitute a valuable alternative to classical non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors for the treatment of inflammatory diseases. Indeed, these latter present diverse side effects, which are reduced or absent in dual-acting agents. In this review, COX and 5-LOX pathways are first described in order to highlight the therapeutic interest of designing such compounds. Various structural families of dual inhibitors are illustrated.
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Affiliation(s)
- Caroline Charlier
- Lab. de Chimie Moléculaire Structurale, Facultés Universitaires N.-D. de la Paix, Rue de Bruxelles 61, B-5000, Namur, Belgium.
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Abstract
Lipoxygenases (LOX) are ubiquitous in plants, and some are important for resistance to pathogens. The soybean LOX (SLOX) remain the prototypes for studying lipoxygenation. The 3-D structures of SLOX-1 and -3 reveal an N-terminal beta-barrel and a C-terminal catalytic domain. The beta-barrel with 30 kDa of the N-terminal peptide chain of SLOX-1 can be separated from the catalytic domain (60 kDa), which is a functional lipoxygenase designated "mini-LOX." The 3-D structures have made it possible to predict and interpret effects of point mutations on catalytic parameters and on the substrate and position specificity and to identify the catalytic base as Fe3+-OH-. The first catalytic step, hydrogen abstraction at C-11 of linoleic acid by Fe3+-OH-, is associated with a very large isotope effect (20-80), which can be explained by the quantum-mechanical concept of hydrogen tunneling "through a 2-D potential barrier." The prosthetic iron of SLOX-3 can be extracted and the apoenzyme can incorporate Fe3+ and regain LOX activity. Plant LOX can be elicited by fungal pathogens. One fungal LOX has been cloned and characterized. It is secreted by the take-all fungus, and the enzyme may contribute to its detrimental actions on wheat roots. The primary structure of Mn-LOX shows that it belongs to the LOX gene family, the metal ligands appear to be homologous, and electron paramagnetic resonance (EPR) spectra suggest redox cycling between Mn2+ and Mn3+. The hypothetical catalytic base, Mn3+-OH-, abstracts the pro-S hydrogen at C-11, and molecular oxygen is inserted in a suprafacial way at C-11 and -13 in a 1:3 ratio. Mn-LOX catalyses the conversion of the 11S-hydroperoxide to 13R-hydroperoxylinoleic acid. Mn-LOX is a novel tool for studying lipoxygenation and plant-fungal interactions.
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Affiliation(s)
- Ernst H Oliw
- Department of Pharmaceutical Biosciences, Uppsala University. Sweden.
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Kühn H, Borchert A. Regulation of enzymatic lipid peroxidation: the interplay of peroxidizing and peroxide reducing enzymes. Free Radic Biol Med 2002; 33:154-72. [PMID: 12106812 DOI: 10.1016/s0891-5849(02)00855-9] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
For a long time lipid peroxidation has only been considered a deleterious process leading to disruption of biomembranes and thus, to cellular dysfunction. However, when restricted to a certain cellular compartment and tightly regulated, lipid peroxidation may have beneficial effects. Early on during evolution of living organisms special lipid peroxidizing enzymes, called lipoxygenases, appeared and they have been conserved during phylogenesis of plants and animals. In fact, a diverse family of lipoxygenase isoforms has evolved starting from a putative ancient precursor. As with other enzymes, lipoxygenases are regulated on various levels of gene expression and there are endogenous antagonists controlling their cellular activity. Among the currently known mammalian lipoxygenase isoforms only 12/15-lipoxygenases are capable of directly oxygenating ester lipids even when they are bound to membranes and lipoproteins. Thus, these enzymes represent the pro-oxidative part in the cellular metabolism of complex hydroperoxy ester lipids. Its metabolic counterplayer, representing the antioxidative part, appears to be the phospholipid hydroperoxide glutathione peroxidase. This enzyme is unique among glutathione peroxidases because of its capability of reducing ester lipid hydroperoxides. Thus, 12/15-lipoxygenase and phospholipid hydroperoxide glutathione peroxidase constitute a pair of antagonizing enzymes in the metabolism of hydroperoxy ester lipids, and a balanced regulation of the two proteins appears to be of major cell physiological importance. This review is aimed at summarizing the recent developments in the enzymology and molecular biology of 12/15-lipoxygenase and phospholipid hydroperoxide glutathione peroxidase, with emphasis on cytokine-dependent regulation and their regulatory interplay.
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Affiliation(s)
- Hartmut Kühn
- Institute of Biochemistry, University Clinics Charité, Humboldt University, Berlin, Germany.
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Skrzypczak-Jankun E, Bross RA, Carroll RT, Dunham WR, Funk MO. Three-dimensional structure of a purple lipoxygenase. J Am Chem Soc 2001; 123:10814-20. [PMID: 11686682 DOI: 10.1021/ja011759t] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polyunsaturated fatty acid metabolism is governed primarily by two enzymes, prostaglandin H synthase and lipoxygenase. The crystal structure of the metastable product-oxidized purple form of soybean lipoxygenase-3 was determined at 2.0 A resolution. The data reveal that the chromophore corresponds to an iron-peroxide complex, a potential intermediate in the catalyzed reaction. A significant alteration of the iron site accompanies the formation of the complex. The structure, the first for a fatty acid-lipoxygenase complex, also reveals an unexpected mode of binding, and identifies amino acid residues that may play significant roles in catalysis, regio- and stereoselectivity.
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Affiliation(s)
- E Skrzypczak-Jankun
- Department of Chemistry, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
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