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Figueiredo PR, Almeida BC, Dourado DFAR, Sousa AF, Silvestre AJD, Carvalho ATP. Enzymatic Synthesis of Poly(caprolactone): A QM/MM Study. ChemCatChem 2020. [DOI: 10.1002/cctc.202000780] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Pedro R. Figueiredo
- CNC – Center for Neuroscience and Cell Biology Institute for Interdisciplinary Research (IIIUC) University of Coimbra 3004-504 Coimbra Portugal
| | - Beatriz C. Almeida
- CNC – Center for Neuroscience and Cell Biology Institute for Interdisciplinary Research (IIIUC) University of Coimbra 3004-504 Coimbra Portugal
| | - Daniel F. A. R. Dourado
- Almac Sciences Department of Biocatalysis and Isotope Chemistry Almac House 20 Seagoe Industrial Estate Craigavon BT63 5QD Northern Ireland UK
| | | | | | - Alexandra T. P. Carvalho
- CNC – Center for Neuroscience and Cell Biology Institute for Interdisciplinary Research (IIIUC) University of Coimbra 3004-504 Coimbra Portugal
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Meyer MP, Klinman JP. Investigating inner-sphere reorganization via secondary kinetic isotope effects in the C-H cleavage reaction catalyzed by soybean lipoxygenase: tunneling in the substrate backbone as well as the transferred hydrogen. J Am Chem Soc 2011; 133:430-9. [PMID: 21192631 PMCID: PMC3090704 DOI: 10.1021/ja1050742] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work describes the application of NMR to the measurement of secondary deuterium (2° (2)H) and carbon-13 ((13)C) kinetic isotope effects (KIEs) at positions 9-13 within the substrate linoleic acid (LA) of soybean lipoxygenase-1. The KIEs have been measured using LA labeled with either protium (11,11-h2-LA) or deuterium (11,11-d2-LA) at the reactive C11 position, which has been previously shown to yield a primary deuterium isotope effect of ca. 80. The conditions of measurement yield the intrinsic 2° (2)H and (13)C KIEs on k(cat)/K(m) directly for 11,11-d2-LA, whereas the values for the 2° (2)H KIEs for 11,11-h2-LA are obtained after correction for a kinetic commitment. The pattern of the resulting 2° (2)H and (13)C isotope effects reveals values that lie far above those predicted from changes in local force constants. Additionally, many of the experimental values cannot be modeled by electronic effects, torsional strain, or the simple inclusion of a tunneling correction to the rate. Although previous studies have shown the importance of extensive tunneling for cleavage of the primary hydrogen at C11 of LA, the present findings can only be interpreted by extending the conclusion of nonclassical behavior to the secondary hydrogens and carbons that flank the position undergoing C-H bond cleavage. A quantum mechanical method introduced by Buhks et al. [J. Phys. Chem. 1981, 85, 3763] to model the inner-sphere reorganization that accompanies electron transfer has been shown to be able to reproduce the scale of the 2° (2)H KIEs.
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Affiliation(s)
- Matthew P. Meyer
- To whom correspondence should be addressed. J.P.K.: Tel: 510-642-2668; Fax: 510-643-6232; . MPM: Tel: 209-228-2983; Fax: 209-675-8042;
| | - Judith P. Klinman
- Departments of Chemistry and of Molecular and Cell Biology and the California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720
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3
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X-Ray absorption spectroscopic studies on iron in soybean lipoxygenase: A model for mammalian lipoxygenases. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19901090302] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pu J, Gao J, Truhlar DG. Multidimensional tunneling, recrossing, and the transmission coefficient for enzymatic reactions. Chem Rev 2006; 106:3140-69. [PMID: 16895322 PMCID: PMC4478620 DOI: 10.1021/cr050308e] [Citation(s) in RCA: 288] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jingzhi Pu
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455-0431
| | - Jiali Gao
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455-0431
| | - Donald G. Truhlar
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455-0431
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McGinley CM, van der Donk WA. Synthesis of site-specifically deuterated arachidonic acid derivatives containing a remote tritium radiolabel. J Labelled Comp Radiopharm 2006; 49:545-558. [DOI: 10.1002/jlcr.1073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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6
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Kitaguchi H, Ohkubo K, Ogo S, Fukuzumi S. Electron-Transfer Oxidation Properties of Unsaturated Fatty Acids and Mechanistic Insight into Lipoxygenases. J Phys Chem A 2006; 110:1718-25. [PMID: 16451000 DOI: 10.1021/jp054648f] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rate constants of photoinduced electron-transfer oxidation of unsaturated fatty acids with a series of singlet excited states of oxidants in acetonitrile at 298 K were examined and the resulting electron-transfer rate constants (k(et)) were evaluated in light of the free energy relationship of electron transfer to determine the one-electron oxidation potentials (E(ox)) of unsaturated fatty acids and the intrinsic barrier of electron transfer. The k(et) values of linoleic acid with a series of oxidants are the same as the corresponding k(et) values of methyl linoleate, linolenic acid, and arachidonic acid, leading to the same E(ox) value of linoleic acid, methyl linoleate, linolenic acid, and arachidonic acid (1.76 V vs SCE), which is significantly lower than that of oleic acid (2.03 V vs SCE) as indicated by the smaller k(et) values of oleic acid than those of other unsaturated fatty acids. The radical cation of linoleic acid produced in photoinduced electron transfer from linoleic acid to the singlet excited state of 10-methylacridinium ion as well as that of 9,10-dicyanoanthracene was detected by laser flash photolysis experiments. The apparent rate constant of deprotonation of the radical cation of linoleic acid was determined as 8.1 x 10(3) s(-1). In the presence of oxygen, the addition of oxygen to the deprotonated radical produces the peroxyl radical, which has successfully been detected by ESR. No thermal electron transfer or proton-coupled electron transfer has occurred from linoleic acid to a strong one-electron oxidant, Ru(bpy)3(3+) (bpy = 2,2'-bipyridine) or Fe(bpy)3(3+). The present results on the electron-transfer and proton-transfer properties of unsaturated fatty acids provide valuable mechanistic insight into lipoxygenases to clarify the proton-coupled electron-transfer process in the catalytic function.
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Affiliation(s)
- Hironori Kitaguchi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
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Rådmark O, Samuelsson B. Regulation of 5-lipoxygenase enzyme activity. Biochem Biophys Res Commun 2005; 338:102-10. [PMID: 16122704 DOI: 10.1016/j.bbrc.2005.08.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 08/04/2005] [Indexed: 11/27/2022]
Abstract
In this article, regulation of human 5-lipoxygenase enzyme activity is reviewed. First, structural properties and enzyme activities are described. This is followed by the activating factors: Ca2+, membranes, ATP, and lipid hydroperoxide. Also, studies on phosphorylation of 5-lipoxygenase and nuclear localization sequences are reviewed.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-17177 Stockholm, Sweden.
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Okamoto H, Hammarberg T, Zhang YY, Persson B, Watanabe T, Samuelsson B, Rådmark O. Mutation analysis of the human 5-lipoxygenase C-terminus: support for a stabilizing C-terminal loop. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1749:123-31. [PMID: 15848143 DOI: 10.1016/j.bbapap.2005.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Revised: 03/09/2005] [Accepted: 03/09/2005] [Indexed: 10/25/2022]
Abstract
Lipoxygenases contain prosthetic iron, in human 5-lipoxygenase (5LO) the C-terminal isoleucine carboxylate constitutes one of five identified ligands. ATP is one of several factors determining 5LO activity. We compared properties of a series of 5LO C-terminal deletion mutants (one to six amino acid residues deleted). All mutants were enzymatically inactive (expected due to loss of iron), but expression yield (in E. coli) and affinity to ATP-agarose was markedly different. Deletion of up to four C-terminal residues was compatible with good expression and retained affinity to the ATP-column, as for wild-type 5LO. However when also the fifth residue was deleted (Asn-669) expression yield decreased and the affinity to ATP was markedly diminished. This was interpreted as a result of deranged structure and stability, due to loss of a hydrogen bond between Asn-669 and His-399. Mutagenesis of these residues supported this conclusion. In the structure of soybean lipoxygenase-1, a C-terminal loop was pointed out as important for correct orientation of the C-terminus. Accordingly, a hydrogen bond appears to stabilize such a C-terminal loop also in 5LO.
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Affiliation(s)
- Hisayo Okamoto
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-171 77 Stockholm, Sweden
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Hatcher E, Soudackov AV, Hammes-Schiffer S. Proton-coupled electron transfer in soybean lipoxygenase. J Am Chem Soc 2004; 126:5763-75. [PMID: 15125669 DOI: 10.1021/ja039606o] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The proton-coupled electron transfer reaction catalyzed by soybean lipoxygenase-1 is studied with a multistate continuum theory that represents the transferring hydrogen nucleus as a quantum mechanical wave function. The inner-sphere reorganization energy of the iron cofactor is calculated with density functional theory, and the outer-sphere reorganization energy of the protein is calculated with the frequency-resolved cavity model for conformations obtained with docking simulations. Both classical and quantum mechanical treatments of the proton donor-acceptor vibrational motion are presented. The temperature dependence of the calculated rates and kinetic isotope effects is in agreement with the experimental data. The weak temperature dependence of the rates is due to the relatively small free energy barrier arising from a balance between the reorganization energy and the reaction free energy. The unusually high deuterium kinetic isotope effect of 81 is due to the small overlap of the reactant and product proton vibrational wave functions and the dominance of the lowest energy reactant and product vibronic states in the tunneling process. The temperature dependence of the kinetic isotope effect is strongly influenced by the proton donor-acceptor distance with the dominant contribution to the overall rate. This dominant proton donor-acceptor distance is significantly smaller than the equilibrium donor-acceptor distance and is determined by a balance between the larger coupling and the smaller Boltzmann probability as the distance decreases. Thus, the proton donor-acceptor vibrational motion plays a vital role in decreasing the dominant donor-acceptor distance relative to its equilibrium value to facilitate the proton-coupled electron transfer reaction.
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Affiliation(s)
- Elizabeth Hatcher
- Department of Chemistry, 152 Davey Laboratory, Pennsylvania State University, University Park, Pennsylvania, 16802, USA
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Abstract
In this article, it has been attempted to review data primarily on the activation of human 5-lipoxygenase, in vitro and in the cell. First, structural properties and enzyme activities are described. This is followed by the activating factors: Ca2+, membranes, ATP, and lipid hydroperoxide. Also, studies on phosphorylation of 5-lipoxygenase, interaction with other proteins, and the intracellullar mobility of 5-lipoxygenase, are reviewed.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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Affiliation(s)
- Amnon Kohen
- Departments of Chemistry and Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720
| | - Judith P. Klinman
- Departments of Chemistry and Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720
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Moiseyev N, Rucker J, Glickman MH. Reduction of Ferric Iron Could Drive Hydrogen Tunneling in Lipoxygenase Catalysis: Implications for Enzymatic and Chemical Mechanisms. J Am Chem Soc 1997. [DOI: 10.1021/ja9632825] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nimrod Moiseyev
- Contribution from the Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6100, and Department of Cell Biology, Harvard Medical School, Boston Massachusetts 02115
| | - Joseph Rucker
- Contribution from the Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6100, and Department of Cell Biology, Harvard Medical School, Boston Massachusetts 02115
| | - Michael H. Glickman
- Contribution from the Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6100, and Department of Cell Biology, Harvard Medical School, Boston Massachusetts 02115
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Lepley RA, Muskardin DT, Fitzpatrick FA. Tyrosine kinase activity modulates catalysis and translocation of cellular 5-lipoxygenase. J Biol Chem 1996; 271:6179-84. [PMID: 8626407 DOI: 10.1074/jbc.271.11.6179] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Tyrosine kinase activity, a determinant of Src homology domain interactions, has a prominent effect on cellular localization and catalysis by 5-lipoxygenase. Six separate inhibitors of tyrosine kinase each inhibited 5(S)-hydroxyeicosatetraenoic acid formation by HL-60 cells stimulated with calcium ionophore, in the presence or absence of exogenous arachidonic acid substrate, indicating that they modulated cellular 5-lipoxygenase activity. The tyrosine kinase inhibitors also blocked the translocation of 5-lipoxygenase from cytosol to membranes during cellular activation, consistent with their effects on its catalytic activity. These results fit a model which postulates that Src homology domain interactions are a molecular determinant of the processes which coordinate the subcellular localization and functions of 5-lipoxygenase. In addition, we demonstrate that activated leukocytes contain two molecularly distinct forms of 5-lipoxygenase: a phosphorylated form and a nonphosphorylated form. In activated HL-60 cells the pool of phosphorylated 5-lipoxygenase accumulates in the nuclear fraction, not with the membrane or cytosolic fractions. The amount of phosphorylated 5-lipoxygenase is a small fraction of the total. Overall, equilibrium reactions involving the nuclear localizing sequence, the proline-rich SH3 binding motif, and the phosphorylation state of 5-lipoxygenase may each influence its partnership with other cellular proteins and any novel functions derived from such partnerships.
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Affiliation(s)
- R A Lepley
- Department of Pharmacology, University of Colorado Health Science Center, Denver 80262, USA
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Brungs M, Rådmark O, Samuelsson B, Steinhilber D. Sequential induction of 5-lipoxygenase gene expression and activity in Mono Mac 6 cells by transforming growth factor beta and 1,25-dihydroxyvitamin D3. Proc Natl Acad Sci U S A 1995; 92:107-11. [PMID: 7816797 PMCID: PMC42826 DOI: 10.1073/pnas.92.1.107] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
5-Lipoxygenase (5-LO; EC 1.13.11.34) activity in the human monocytic cell line Mono Mac 6 was upregulated by combined treatment with transforming growth factor beta 1 (TGF-beta) and 1,25-dihydroxyvitamin D3 (VD3). In undifferentiated cells, 5-LO enzyme activity was undetectable. After the addition of TGF-beta plus VD3, the activity of intact cells was 800 ng per 10(6) cells--500 times more than the assay detection limit. Also 5-LO protein and mRNA expression were induced > 128-fold and 64-fold, respectively, as compared to undifferentiated cells. Both TGF-beta and VD3 were required for these prominent responses. Either agent alone gave small amounts of 5-LO protein and mRNA but very low 5-LO activities. After the addition of TGF-beta and VD3, the induction of 5-LO protein was obvious after 1 day, but the increase in activity was delayed and did not appear until the second day. Pretreatment of cells with TGF-beta or VD3 alone for 2 days led to 5-LO protein expression but very low enzyme activity. Addition of the lacking second inducer was required for full induction of 5-LO protein expression and for upregulation of enzyme activity. Partial purification of 5-LO from Mono Mac 6 cells and recombination with soluble cellular proteins from different sources indicated the presence of cytosolic factors that affect the activity of 5-LO.
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Affiliation(s)
- M Brungs
- Department of Pharmaceutical Chemistry, University of Tübingen, Germany
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Lepley R, Fitzpatrick F. 5-Lipoxygenase contains a functional Src homology 3-binding motif that interacts with the Src homology 3 domain of Grb2 and cytoskeletal proteins. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)51063-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Lepley R, Fitzpatrick F. Irreversible inactivation of 5-lipoxygenase by leukotriene A4. Characterization of product inactivation with purified enzyme and intact leukocytes. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41990-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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18
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Zhang Y, Lind B, Rådmark O, Samuelsson B. Iron content of human 5-lipoxygenase, effects of mutations regarding conserved histidine residues. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53808-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Percival MD, Denis D, Riendeau D, Gresser MJ. Investigation of the mechanism of non-turnover-dependent inactivation of purified human 5-lipoxygenase. Inactivation by H2O2 and inhibition by metal ions. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 210:109-17. [PMID: 1446663 DOI: 10.1111/j.1432-1033.1992.tb17397.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human 5-lipoxygenase is a non-heme iron protein which is reported to be highly unstable in the presence of oxygen. The results of this investigation demonstrate that H2O2 generated during air oxidation of thiols is the main factor in non-turnover-dependent inactivation of purified recombinant human 5-lipoxygenase for the following reasons: catalase protects against oxygen-dependent inactivation of the enzyme in the presence of dithiothreitol; the active, stable enzyme can be prepared under aerobic conditions with the exclusion of dithiothreitol and contaminating metal ions; 10 microM H2O2 causes the rapid inactivation of the enzyme. The native (ferrous) enzyme is approximately seven times more sensitive to inactivation by H2O2 than the ferric enzyme, suggesting that the mechanism of inactivation involves a Fenton-type reaction of the ferrous enzyme with H2O2, resulting in the formation of an activated oxygen species. Purification of 5-lipoxygenase under aerobic conditions (no dithiothreitol) results in an increase in both the specific activity of the purified protein [up to 70 mumol 5(S)-hydroperoxy-6-trans-8, 11, 14-cis-icosatetraenoic acid (5-HPETE)/mg protein] and in the ratio of specific activity to enzyme iron content compared to enzyme purified under anaerobic conditions in the presence of dithiothreitol. The reaction of the highly active 5-lipoxygenase enzyme shows a dependence on physiological intracellular calcium concentrations, half-maximal product formation being obtained at 0.9 microM free Ca2+. The maximal enzyme activity is also dependent on EDTA and dithiothreitol and low amounts of carrier protein, as well as the known activators PtdCho and ATP. Ca2+ can be substituted by Mn2+, Ba2+ and Sr2+, although lower levels of stimulation are obtained. 5-Lipoxygenase is strongly inhibited by low concentrations (< or = 10 microM) of Zn2+ and Cu2+. The inhibition by Cu2+ is apparently irreversible, whereas that by Zn2+ is slowly reversed (t1/2 = 2 min) in the presence of excess EDTA. These observations on the mechanism of non-turnover-dependent inactivation of 5-lipoxygenase, and the optimisation of assay conditions, have facilitated the purification of large quantities of relatively stable enzyme that will be useful for further kinetic and physical studies.
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Affiliation(s)
- M D Percival
- Department of Biochemistry, Merck Frosst Centre for Therapeutic Research, Pointe-Claire, Dorval, Canada
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Gardner HW. Recent investigations into the lipoxygenase pathway of plants. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1084:221-39. [PMID: 1909580 DOI: 10.1016/0005-2760(91)90063-n] [Citation(s) in RCA: 396] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The plant lipoxygenase (LOX) pathway is in many respects the equivalent of the 'arachidonic acid cascade' in animals. The LOX-catalyzed dioxygenation of the plant fatty acids, linoleic and linolenic acids, is followed by metabolism of the resulting fatty acid hydroperoxides by other enzymes. Although the physiological functions of the end-products do not appear to be fully defined at this time, hormonal and anti-fungal activities have been reported.
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Affiliation(s)
- H W Gardner
- United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL
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Denis D, Falgueyret JP, Riendeau D, Abramovitz M. Characterization of the activity of purified recombinant human 5-lipoxygenase in the absence and presence of leukocyte factors. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67757-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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22
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Kühn H, Heydeck D, Sprecher H. On the mechanistic reasons for the dual positional specificity of the reticulocyte lipoxygenase. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1081:129-34. [PMID: 1900203 DOI: 10.1016/0005-2760(91)90017-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A set of octadecadienoic acid isomers and selected eicosatrienoic acids were tested as substrates for the lipoxygenases from soybeans and reticulocytes. Among the dienoic fatty acids, 8Z,11Z-octadecadienoic acid containing a n - 9 doubly allylic methylene group turned out to be the best substrate for the reticulocyte enzyme. This substrate was converted to its corresponding n - 7 hydroperoxy derivative. The soybean lipoxygenase, in contrast, prefers the 9Z,12Z-octadecadienoic acid (linoleic acid) which is oxygenated to its n - 6 hydroperoxy derivative. In both cases a strong preference for the LS-isomer has been observed. Analysis of the oxygenation products formed from various eicosatrienoic acids indicated that 8Z,11Z,14Z-eicosatrienoic acid was converted by the reticulocyte enzyme to its 12S- and 15S-hydroperoxy derivative in a ratio of about 1:7 (dual positional specificity), whereas the 7Z,10Z,13Z-isomer was oxygenated predominantly (greater than 97%) to its 14S-hydroperoxy derivative (singular positional specificity). 9Z,12Z,15Z-eicosatrienoic acid was oxygenated with a dual positional specificity to the corresponding 13- and 16-hydroperoxy compounds in a ratio of about 7:1. The soybean lipoxygenase converts the 8Z,11Z,14Z-isomer with a singular positional specificity to the corresponding 15S-hydroperoxy derivatives. The 9Z,12Z,15Z-eicosatrienoic acid, however, was oxygenated with a dual positional specificity to its 13S-hydroperoxy and 16S-hydroperoxy derivative in a ratio of about 1:4.
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Affiliation(s)
- H Kühn
- Institute of Biochemistry, School of Medicine (Charité), Humboldt University, Berlin, F.R.G
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