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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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2
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Fischer GJ, Bacon W, Yang J, Palmer JM, Dagenais T, Hammock BD, Keller NP. Lipoxygenase Activity Accelerates Programmed Spore Germination in Aspergillus fumigatus. Front Microbiol 2017; 8:831. [PMID: 28536571 PMCID: PMC5422543 DOI: 10.3389/fmicb.2017.00831] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/24/2017] [Indexed: 12/31/2022] Open
Abstract
The opportunistic human pathogen Aspergillus fumigatus initiates invasive growth through a programmed germination process that progresses from dormant spore to swollen spore (SS) to germling (GL) and ultimately invasive hyphal growth. We find a lipoxygenase with considerable homology to human Alox5 and Alox15, LoxB, that impacts the transitions of programmed spore germination. Overexpression of loxB (OE::loxB) increases germination with rapid advance to the GL stage. However, deletion of loxB (ΔloxB) or its signal peptide only delays progression to the SS stage in the presence of arachidonic acid (AA); no delay is observed in minimal media. This delay is remediated by the addition of the oxygenated AA oxylipin 5-hydroxyeicosatetraenoic acid (5-HETE) that is a product of human Alox5. We propose that A. fumigatus acquisition of LoxB (found in few fungi) enhances germination rates in polyunsaturated fatty acid-rich environments.
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Affiliation(s)
- Gregory J Fischer
- Department of Genetics, University of Wisconsin-Madison, MadisonWI, USA
| | - William Bacon
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, MadisonWI, USA
| | - Jun Yang
- Department of Entomology and Nematology and Comprehensive Cancer Center, University of California, Davis, DavisCA, USA
| | - Jonathan M Palmer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, MadisonWI, USA
| | - Taylor Dagenais
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, MadisonWI, USA
| | - Bruce D Hammock
- Department of Entomology and Nematology and Comprehensive Cancer Center, University of California, Davis, DavisCA, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, MadisonWI, USA
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Soler J, Saura P, García-López D, Masgrau L, Lluch JM, González-Lafont À. How Can Linoleic Acid Be the Preferential Substrate of the Enzyme 15-Lipoxygenase-1? A QM/MM Approach. J Phys Chem B 2015; 120:1950-60. [DOI: 10.1021/acs.jpcb.5b09897] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Jordi Soler
- Departament de Química and ‡Institut de Biotecnologia
i de Biomedicina
(IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Patricia Saura
- Departament de Química and ‡Institut de Biotecnologia
i de Biomedicina
(IBB), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Diego García-López
- 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
| | - 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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Wecksler AT, Kenyon V, Deschamps JD, Holman TR. Substrate specificity changes for human reticulocyte and epithelial 15-lipoxygenases reveal allosteric product regulation. Biochemistry 2008; 47:7364-75. [PMID: 18570379 DOI: 10.1021/bi800550n] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Human reticulocyte 15-lipoxygenase (15-hLO-1) and epithelial 15-lipoxygenase (15-hLO-2) have been implicated in a number of human diseases, with differences in their substrate specificity potentially playing a central role. In this paper, we present a novel method for accurately measuring the substrate specificity of the two 15-hLO isozymes and demonstrate that both cholate and specific LO products affect substrate specificity. The linoleic acid (LA) product, 13-hydroperoxyoctadienoic acid (13-HPODE), changes the ( k cat/ K m) (AA)/( k cat/ K m) (LA) ratio more than 5-fold for 15-hLO-1 and 3-fold for 15-hLO-2, while the arachidonic acid (AA) product, 12-( S)-hydroperoxyeicosatetraenoic acid (12-HPETE), affects only the ratio of 15-hLO-1 (more than 5-fold). In addition, the reduced products, 13-( S)-hydroxyoctadecadienoic acid (13-HODE) and 12-( S)-hydroxyeicosatetraenoic acid (12-HETE), also affect substrate specificity, indicating that iron oxidation is not responsible for the change in the ( k cat/ K m) (AA)/( k cat/ K m) (LA) ratio. These results, coupled with the dependence of the 15-hLO-1 k cat/ K m kinetic isotope effect ( (D) k cat/ K m) on the presence of 12-HPETE and 12-HETE, indicate that the allosteric site, previously identified in 15-hLO-1 [Mogul, R., Johansen, E., and Holman, T. R. (1999) Biochemistry 39, 4801-4807], is responsible for the change in substrate specificity. The ability of LO products to regulate substrate specificity may be relevant with respect to cancer progression and warrants further investigation into the role of this product-feedback loop in the cell.
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Affiliation(s)
- Aaron T Wecksler
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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Abstract
Tumor necrosis factor (TNF) can induce apoptosis in a number of different cell types. This response often depends on the activity of cytosolic phospholipase A2 (cPLA2), which catalyzes the release of arachidonic acid from the sn-2 position of membrane phospholipids. In this study, we investigate the ability of arachidonic acid itself to cause cell death. We show that in assays with 10% fetal bovine serum (FBS) arachidonic acid will not kill, nor does act synergistically with TNF. In contrast, by lowering the concentration of FBS to 2%, it is possible to use arachidonic acid to induce cell death. Arachidonic acid-induced cell death was judged to be apoptotic based on morphology and the cleavage of poly(ADP)ribose polymerase. Arachidonic acid was able to kill all cell lines tested including two human melanoma-derived cell lines, and susceptibility to arachidonic acid was not influenced by adenovirus gene products that control susceptibility to TNF. Finally, we show that arachidonic acid is unique among 20 carbon fatty acids for its ability to induce apoptosis and that several other unsaturated, but not saturated fatty acids can also induce apoptosis.
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Affiliation(s)
- L A Wolf
- Department of Microbiology, North Carolina State University, Raleigh 27695, USA
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Prigge ST, Gaffney BJ, Amzel LM. Relation between positional specificity and chirality in mammalian lipoxygenases. NATURE STRUCTURAL BIOLOGY 1998; 5:178-9. [PMID: 9501907 PMCID: PMC3904545 DOI: 10.1038/nsb0398-178] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Prigge ST, Boyington JC, Faig M, Doctor KS, Gaffney BJ, Amzel LM. Structure and mechanism of lipoxygenases. Biochimie 1997; 79:629-36. [PMID: 9479444 DOI: 10.1016/s0300-9084(97)83495-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In mammals, lipoxygenases catalyze the formation of hydroperoxides as the first step in the biosynthesis of several inflammatory mediators. The substrate of this reaction, arachidonic acid, is the key precursor of two families of potent physiological effectors. It is the branch point between two central pathways: one, involving the enzyme cyclooxygenase, leads to the synthesis of prostaglandins and thromboxanes; the other, involving lipoxygenases, leads to the synthesis of leukotrienes and lipoxins, compounds that regulate important cellular responses in inflammation and immunity. While aspirin and other non-steroidal anti-inflammatory compounds are potent inhibitors of cyclooxygenase, no effective pharmacological inhibitor of lipoxygenase is presently available. Lipoxygenases are large non-heme, iron-containing enzymes that use molecular oxygen for the diooxygenation of arachidonic acid to form hydroperoxides, the first step in the biosynthetic pathways leading to leukotrienes and lipoxins. Because of the importance of these compounds, lipoxygenases have been the subject of extensive study: from detailed kinetic measurements to cloning, expression, and site-directed mutagenesis. The sequences of over 50 lipoxygenases have been reported. In addition, the structure of soybean lipoxygenase-1, determined by X-ray diffraction methods, has recently been reported. The structure revealed that the 839 amino acids in the protein are organized in two domains: a beta-sheet N-terminal domain and a large, mostly helical C-terminal domain. The iron is present in the C-terminal domain facing two internal cavities that are probably the conduits through which the fatty acid and molecular oxygen gain access to the metal. Models of the mammalian lipoxygenases based on the soybean structure provide clues about the structural determinants of the positional specificity of the enzyme, and can be used as targets for the design of more effective inhibitors.
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Affiliation(s)
- S T Prigge
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Prigge ST, Boyington JC, Gaffney BJ, Amzel LM. Structure conservation in lipoxygenases: structural analysis of soybean lipoxygenase-1 and modeling of human lipoxygenases. Proteins 1996; 24:275-91. [PMID: 8778775 DOI: 10.1002/(sici)1097-0134(199603)24:3<275::aid-prot1>3.0.co;2-g] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Lipoxygenases are a class of non-heme iron dioxygenases which catalyze the hydroperoxidation of fatty acids for the biosynthesis of leukotrienes and lipoxins. The structure of the 839-residue soybean lipoxygenase-1 was used as a template to model human 5-, 12-, and 15-lipoxygenases. A distance-based algorithm for placing side chains in a low homology environment (only the four iron ligands were fixed during side chain placement) was devised. Twenty-six of the 56 conserved lipoxygenase residues were grouped in four distinct regions of the enzyme. These regions were analyzed to discern whether the side chain interactions could be duplicated in the models or whether alternate conformers should be considered. The effects of site directed mutagenesis variants were rationalized using the models of the human lipoxygenases. In particular, variants which shifted positional specificity between 12- and 15-lipoxygenase activity were analyzed. Analysis of active site residues produced a model which accounts for observed lipoxygenase positional specificity and stereospecificity.
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Affiliation(s)
- S T Prigge
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
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