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Nokhsorov VV, Senik SV, Sofronova VE, Kotlova ER, Misharev AD, Chirikova NK, Dudareva LV. Role of Lipids of the Evergreen Shrub Ephedra monosperma in Adaptation to Low Temperature in the Cryolithozone. PLANTS (BASEL, SWITZERLAND) 2022; 12:15. [PMID: 36616144 PMCID: PMC9823733 DOI: 10.3390/plants12010015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Lipids are the fundamental components of cell membranes and they play a significant role in their integrity and fluidity. The alteration in lipid composition of membranes has been reported to be a major response to abiotic environmental stresses. Seasonal dynamics of membrane lipids in the shoots of Ephedra monosperma J.G. Gmel. ex C.A. Mey. growing in natural conditions of permafrost ecosystems was studied using HPTLC, GC-MS and ESI-MS. An important role of lipid metabolism was established during the autumn-winter period when the shoots of the evergreen shrub were exposed to low positive (3.6 °C), negative (-8.3 °C) and extremely low temperatures (-38.4 °C). Maximum accumulation of phosphatidic acid (PA), the amount of which is times times greater than the sum of phosphatidylcholine and phosphatidylethanolamine (PC + PE) was noted in shoots of E. monosperma in the summer-autumn period. The autumn hardening period (3.6 °C) is accompanied by active biosynthesis and accumulation of membrane lipids, a decrease of saturated 34:1 PCs, 34:1 PEs and 34:1 PAs, and an increase in unsaturated long-chain 38:5 PEs, 38:6 PEs, indicating that the adaptation of E. monosperma occurs not at the level of lipid classes but at the level of molecular species. At a further decrease of average daily air temperature in October (-8.3 °C) a sharp decline of PA level was registered. At an extreme reduction of environmental temperature (-38.4 °C) the content of non-bilayer PE and PA increases, the level of unsaturated fatty acids (FA) rises due to the increase of C18:2(Δ9,12) and C18:3(Δ9,12,15) acids and the decrease of C16:0 acids. It is concluded that changes in lipid metabolism reflect structural and functional reorganization of cell membranes and are an integral component of the complex process of plant hardening to low temperatures, which contributes to the survival of E. monosperma monocotyledonous plants in the extreme conditions of the Yakutia cryolithozone.
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Affiliation(s)
- Vasiliy V. Nokhsorov
- Institute for Biological Problems of Cryolithozone, Siberian Branch of Russian Academy of Sciences, 41 Lenina Av., 677000 Yakutsk, Russia
| | - Svetlana V. Senik
- Komarov Botanical Institute, Russian Academy of Sciences, 2 Professor Popov str., 197376 St. Petersburg, Russia
| | - Valentina E. Sofronova
- Institute for Biological Problems of Cryolithozone, Siberian Branch of Russian Academy of Sciences, 41 Lenina Av., 677000 Yakutsk, Russia
| | - Ekaterina R. Kotlova
- Komarov Botanical Institute, Russian Academy of Sciences, 2 Professor Popov str., 197376 St. Petersburg, Russia
| | - Alexander D. Misharev
- Chemical Analysis and Materials Research Centre, Saint-Petersburg State University, 198504 St. Petersburg, Russia
| | - Nadezhda K. Chirikova
- Institute of Natural Science, North-Eastern Federal University, 58 Belinsky str., 677027 Yakutsk, Russia
| | - Lyubov V. Dudareva
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of Russian Academy of Sciences, 132 Lermontova str., 664033 Irkutsk, Russia
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Tupec M, Culka M, Machara A, Macháček S, Bím D, Svatoš A, Rulíšek L, Pichová I. Understanding desaturation/hydroxylation activity of castor stearoyl Δ9-Desaturase through rational mutagenesis. Comput Struct Biotechnol J 2022; 20:1378-1388. [PMID: 35386101 PMCID: PMC8940945 DOI: 10.1016/j.csbj.2022.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/11/2022] [Accepted: 03/11/2022] [Indexed: 01/17/2023] Open
Abstract
Rationally designed mutations in the Δ9 desaturase promoted hydroxylation activity. Proton and electron transfer to the active site is crucial for the Δ9D to desaturate Detailed analysis of all enzymatic products of the Δ9D was carried out Insight into the chemo-, and stereoselectivity of non-heme diiron enzymes was obtained
A recently proposed reaction mechanism of soluble Δ9 desaturase (Δ9D) allowed us to identify auxiliary residues His203, Asp101, Thr206 and Cys222 localized near the di-iron active site that are supposedly involved in the proton transfer (PT) to and from the active site. The PT, along with the electron transfer (ET), seems to be crucial for efficient desaturation. Thus, perturbing the major PT chains is expected to impair the native reaction and (potentially) amplify minor reaction channels, such as the substrate hydroxylation. To verify this hypothesis, we mutated the four residues mentioned above into their counterparts present in a soluble methane monooxygenase (sMMO), and determined the reaction products of mutants. We found that the mutations significantly promote residual monohydroxylation activities on stearoyl-CoA, often at the expense of native desaturation activity. The favored hydroxylation positions are C9, followed by C10 and C11. Reactions with unsaturated substrate, oleoyl-CoA, yield erythro-9,10-diol, cis-9,10-epoxide and a mixture of allylic alcohols. Additionally, using 9- and 11-hydroxystearoyl-CoA, we showed that the desaturation reaction can proceed only with the hydroxyl group at position C11, whereas the hydroxylation reaction is possible in both cases, i.e. with hydroxyl at position C9 or C11. Despite the fact that the overall outcome of hydroxylation is rather modest and that it is mostly the desaturation/hydroxylation ratio that is affected, our results broaden understanding of the origin of chemo- and stereoselectivity of the Δ9D and provide further insight into the catalytic action of the NHFe2 enzymes.
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Affiliation(s)
- Michal Tupec
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
| | - Martin Culka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
| | - Aleš Machara
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
| | - Stanislav Macháček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
| | - Daniel Bím
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
| | - Aleš Svatoš
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
- Max-Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena 07745, Germany
| | - Lubomír Rulíšek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
- Corresponding authors.
| | - Iva Pichová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, Prague 16610, Czech Republic
- Corresponding authors.
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Influence of Extremely Low Temperatures of the Pole of Cold on the Lipid and Fatty-Acid Composition of Aerial Parts of the Horsetail Family (Equisetaceae). PLANTS 2021; 10:plants10050996. [PMID: 34067613 PMCID: PMC8156520 DOI: 10.3390/plants10050996] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 11/17/2022]
Abstract
The lipid composition of two species of vascular plants, Equisetum variegatum Schleich. ex. Web. and E. scirpoides Michx., growing in the permafrost zone (Northeastern Yakutia, the Pole of Cold of the Northern Hemisphere), with average daily air temperatures in summer of +17.8 °C, in autumn of +0.6 °C, and in winter of −46.7 °C, was comparatively studied. The most significant seasonal trend of lipid composition was an accumulation of PA in both horsetail species in the autumn–winter period. Cold acclimation in autumn was accompanied by a decrease in the proportion of bilayer-forming lipids (phosphatidylcholine in the non-photosynthetic membranes and MGDG in photosynthetic membranes), an increase in the desaturation degree due to the accumulation of triene fatty acids (E. scirpoides), and an accumulation of betaine lipids O-(1,2-diacylglycero)-N,N,N-trimethylhomoserine (DGTS). The inverse changes in some parameters were registered in the winter period, including an increase in the proportion of “bilayer” lipids and decrease in the unsaturation degree. According to the data obtained, it can be concluded that high levels of accumulation of membrane lipids and polyunsaturated FAs (PUFAs), as well as the presence of Δ5 FAs in lipids, are apparently features of cold hardening of perennial herbaceous plants in the cryolithozone.
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Mustiga GM, Morrissey J, Stack JC, DuVal A, Royaert S, Jansen J, Bizzotto C, Villela-Dias C, Mei L, Cahoon EB, Seguine E, Marelli JP, Motamayor JC. Identification of Climate and Genetic Factors That Control Fat Content and Fatty Acid Composition of Theobroma cacao L. Beans. FRONTIERS IN PLANT SCIENCE 2019; 10:1159. [PMID: 31681345 PMCID: PMC6802002 DOI: 10.3389/fpls.2019.01159] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/26/2019] [Indexed: 05/04/2023]
Abstract
The main ingredients of chocolate are usually cocoa powder, cocoa butter, and sugar. Both the powder and the butter are extracted from the beans of the cacao tree (Theobroma cacao L.). The cocoa butter represents the fat in the beans and possesses a unique fatty acid profile that results in chocolate's characteristic texture and mouthfeel. Here, we used a linkage mapping population and phenotypic data of 3,292 samples from 420 progeny which led to the identification of 27 quantitative trait loci (QTLs) for fatty acid composition and six QTLs for fat content. Progeny showed extensive variation in fat levels and composition, with the level of palmitic acid negatively correlated to the sum of stearic acid, oleic acid, and linoleic acid. A major QTL explaining 24% of the relative level of palmitic acid was mapped to the distal end of chromosome 4, and those higher levels of palmitic acid were associated with the presence of a haplotype from the "TSH 1188" parent in the progeny. Within this region of chromosome 4 is the Thecc1EG017405 gene, an orthologue and isoform of the stearoyl-acyl carrier protein (ACP) desaturase (SAD) gene in plants, which is involved in fatty acid biosynthesis. Besides allelic differences, we also show that climate factors can change the fatty acid composition in the beans, including a significant positive correlation between higher temperatures and the higher level of palmitic acid. Moreover, we found a significant pollen donor effect from the variety "SIAL 70" which was associated with decreased palmitic acid levels.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Linkai Mei
- Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, NE, United States
| | - Edgar B. Cahoon
- Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, NE, United States
| | - Ed Seguine
- Seguine Cacao/Guittard Chocolate Co, Arroyo Grande, CA, United States
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Pushkarova NO, Kalista MS, Kharkhota MA, Rakhmetov D, Kuchuk MV. Crambe tataria sebeók seeds and plants grown in vitro and in vivo fatty acid composition comparison. POTRAVINARSTVO 2016. [DOI: 10.5219/646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Methods of in vitro conservation offer a number of advantages for endangered species preservation. Crambe tataria Sebeók biochemistry study (fatty acid (FA) composition, antioxidant activity (AOA), polyfructan and total soluble protein content) is fairly importaint and could show the potential value of this species in agriculture, Food and Chemical Industry or pharmacology including its use as a source of valuble genetic material and could lead to new promising sources of biofuel discovery. Also, comparison of in vitro and in vivo cultured plants could point out to the effect of in vitro culture methods on plants biochemical composition Fatty acid (FA) content was determined using Gas chromatography-mass spectrophotometry (GC/MS) of fatty acid ethers. Antioxidant activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method. Total soluble protein content was measured using Bradford method and polyfructan content determination was based upon ketosugars ability to color in the acidic environment with resorcinol. Plants that were grown under in vitro and in vivo conditions and seeds were used in this research. Obtained data showed that C. tataria plants had high AOA and total soluble protein content along with high total FA content along with high content of α-Linolenic acid and absence of erucic acid. Difference in biochemical composition between plants grown in aseptic and not aseptic conditions was shown.
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Pushkarova NO. BIOTECHNOLOGICAL APPROACHES FOR CONSERVATION OF THE ENDANGERED SPECIES Crambe koktebelica (JUNGE) N. BUSCH AND EFFECT OF ASEPTIC IN VITRO CULTIVATION ON ITS BIOCHEMICAL PROPERTIES. BIOTECHNOLOGIA ACTA 2016. [DOI: 10.15407/biotech9.04.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Alaudinova EV, Mironov PV. Lipids of the meristems of the main coniferous edificators from central siberia under low-temperature adaptation: 2. Features of the fatty acid metabolism of phospholipids from winter meristems of Larix sibirica Ledeb., Picea obovata L., and Pinus sylvestris L. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010. [DOI: 10.1134/s1068162010070149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Tremolieres A, Dubacq J, Drapier D, Muller M, Mazliak P. In vitro cooperation between plastids and microsomes in the biosynthesis of leaf lipids. FEBS Lett 2001. [DOI: 10.1016/0014-5793(80)80877-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Peyou-Ndi MM, Watts JL, Browse J. Identification and characterization of an animal delta(12) fatty acid desaturase gene by heterologous expression in Saccharomyces cerevisiae. Arch Biochem Biophys 2000; 376:399-408. [PMID: 10775428 DOI: 10.1006/abbi.2000.1733] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned a Caenorhabditis elegans cDNA encoding a Delta12 fatty acid desaturase and demonstrated its activity by heterologous expression in Saccharomyces cerevisiae. The predicted protein is highly homologous both to the cloned plant genes with similar function and to the published sequence of the C. elegans omega-3 fatty acid desaturase. In addition, it conforms to the structural constraints expected of a membrane-bound fatty acid desaturase including the canonical histidine-rich regions. This is the first report of a cloned animal Delta(12) desaturase gene. Expression of this cDNA in yeast resulted in the accumulation of 16:2 and 18:2 (linoleic) acids. The increase of membrane fluidity brought about by this change in unsaturation was measured. The production of polyunsaturated fatty acids in yeast cells and the concomitant increase in membrane fluidity was correlated with a modest increase in growth rate at low temperature and with increased resistance to ethanol and oxidative stress.
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Affiliation(s)
- M M Peyou-Ndi
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340, USA
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11
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Abstract
Fatty acid desaturases are enzymes that introduce double bonds into fatty acyl chains. They are present in all groups of organisms, i.e., bacteria, fungi, plants and animals, and play a key role in the maintenance of the proper structure and functioning of biological membranes. The desaturases are characterized by the presence of three conserved histidine tracks which are presumed to compose the Fe-binding active centers of the enzymes. Recent findings on the structure and expression of different types of fatty acid desaturase in cyanobacteria, plants and animals are reviewed in this article. Roles of individual desaturases in temperature acclimation and principles of regulation of the desaturase genes are discussed.
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Affiliation(s)
- D A Los
- Institute of Plant Physiology, Moscow, Russia
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12
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Abstract
Desaturation of a fatty acid first involves the enzymatic removal of a hydrogen from a methylene group in an acyl chain, a highly energy-demanding step that requires an activated oxygen intermediate. Two types of desaturases have been identified, one soluble and the other membrane-bound, that have different consensus motifs. Database searching for these motifs reveals that these enzymes belong to two distinct multifunctional classes, each of which includes desaturases, hydroxylases, and epoxidases that act on fatty acids or other substrates. The soluble class has a consensus motif consisting of carboxylates and histidines that coordinate an active site diiron cluster. The integral membrane class contains a different consensus motif composed of histidines. Biochemical and structural similarities between the integral membrane enzymes suggest that this class also uses a diiron cluster for catalysis. Soluble and membrane enzymes have been successfully re-engineered for substrate specificity and reaction outcome. It is anticipated that rational design of these enzymes will result in new and desired activities that may form the basis for improved oil crops.
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Affiliation(s)
- John Shanklin
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973; e-mail:
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Cahoon EB, Lindqvist Y, Schneider G, Shanklin J. Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position. Proc Natl Acad Sci U S A 1997; 94:4872-7. [PMID: 9144157 PMCID: PMC24598 DOI: 10.1073/pnas.94.10.4872] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Acyl-acyl carrier protein (ACP) desaturases introduce double bonds at specific positions in fatty acids of defined chain lengths and are one of the major determinants of the monounsaturated fatty acid composition of vegetable oils. Mutagenesis studies were conducted to determine the structural basis for the substrate and double bond positional specificities displayed by acyl-ACP desaturases. By replacement of specific amino acid residues in a Delta6-palmitoyl (16:0)-ACP desaturase with their equivalents from a Delta9-stearoyl (18:0)-ACP desaturase, mutant enzymes were identified that have altered fatty acid chain-length specificities or that can insert double bonds into either the Delta6 or Delta9 positions of 16:0- and 18:0-ACP. Most notably, by replacement of five amino acids (A181T/A200F/S205N/L206T/G207A), the Delta6-16:0-ACP desaturase was converted into an enzyme that functions principally as a Delta9-18:0-ACP desaturase. Many of the determinants of fatty acid chain-length specificity in these mutants are found in residues that line the substrate binding channel as revealed by x-ray crystallography of the Delta9-18:0-ACP desaturase. The crystallographic model of the active site is also consistent with the diverged activities associated with naturally occurring variant acyl-ACP desaturases. In addition, on the basis of the active-site model, a Delta9-18:0-ACP desaturase was converted into an enzyme with substrate preference for 16:0-ACP by replacement of two residues (L118F/P179I). These results demonstrate the ability to rationally modify acyl-ACP desaturase activities through site-directed mutagenesis and represent a first step toward the design of acyl-ACP desaturases for the production of novel monounsaturated fatty acids in transgenic oilseed crops.
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Affiliation(s)
- E B Cahoon
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Harwood JL. Recent advances in the biosynthesis of plant fatty acids. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1301:7-56. [PMID: 8652653 DOI: 10.1016/0005-2760(95)00242-1] [Citation(s) in RCA: 248] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- J L Harwood
- School of Molecular and Medical Biosciences, University of Wales, Cardiff, UK
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15
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Cahoon EB, Mills LA, Shanklin J. Modification of the fatty acid composition of Escherichia coli by coexpression of a plant acyl-acyl carrier protein desaturase and ferredoxin. J Bacteriol 1996; 178:936-9. [PMID: 8550538 PMCID: PMC177750 DOI: 10.1128/jb.178.3.936-939.1996] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Expression of a plant delta 6-palmitoyl (16:0)-acyl carrier protein desaturase in Escherichia coli resulted in the accumulation of the novel monounsaturated fatty acids delta 6-hexadecenoic acid (16:1 delta 6) and delta 8-octadecenoic acid. Amounts of 16:1 delta 6 accumulated by E. coli were increased more than twofold by the expression of a plant ferredoxin together with the delta 6-16:0-acyl carrier protein desaturase.
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Affiliation(s)
- E B Cahoon
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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Kouzaki N, Kawashima H, Chung MC, Shimizu S. Purification and characterization of two forms of cytochrome b5 from an arachidonic acid-producing fungus, Mortierella hygrophila. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1256:319-26. [PMID: 7786894 DOI: 10.1016/0005-2760(95)00037-d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two forms of cytochrome b5 have been purified from the microsomes of an arachidonic acid-producing fungus, Mortierella hygrophila IFO 5941, after detergent solubilization. They have monomeric molecular masses of about 16 kDa and 19 kDa. Their absorption spectra are similar to those of mammalian cytochrome b5s. Their amino acid compositions show some similarity to those of mammalian cytochrome b5s, but the contents of some amino acids (glycine, alanine, aspartic acid + asparagine, glutamic acid + glutamine, arginine, proline, histidine, leucine and lysine) are unique to the cytochrome b5s of M. hygrophila. Some of their internal peptide sequences also show close homology with those of some mammals (approx. 65 to 67%), while some others show no or little homology. The addition of various acyl-CoAs to NADH-reduced microsomes caused an abrupt shiftdown of the steady state reduction level of cytochrome b5. This indicates the increased utilization of electrons for the desaturation process and may suggest that the cytochrome b5s of this fungus actually take part in its microsomal desaturation system for polyunsaturated fatty acid biosynthesis as electron carriers.
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Affiliation(s)
- N Kouzaki
- Department of Agricultural Chemistry, Kyoto University, Japan
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17
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Cahoon EB, Cranmer AM, Shanklin J, Ohlrogge JB. delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47015-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Fox BG, Shanklin J, Ai J, Loehr TM, Sanders-Loehr J. Resonance Raman evidence for an Fe-O-Fe center in stearoyl-ACP desaturase. Primary sequence identity with other diiron-oxo proteins. Biochemistry 1994; 33:12776-86. [PMID: 7947683 DOI: 10.1021/bi00209a008] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The stearoyl-ACP delta 9 desaturase from plants is a new example of a growing number of proteins that contain oxo- or hydroxo-bridged diiron clusters. On the basis of differences in primary sequence motifs providing the cluster ligands and upon structural differences elucidated by X-ray crystallography, we now propose that the presently known, soluble diiron-oxo proteins can be grouped into two classes, I and II. Class I contains hemerythrin, myohemerythrin, and, possibly, purple acid phosphatase. Class II contains ribonucleotide reductases, bacterial hydrocarbon hydroxylases (methane monooxygenase, toluene-4-monooxygenase, and phenol hydroxylase), rubrerythrin, and stearoyl-ACP desaturases. Through the use of resonance Raman spectroscopy, we have detected symmetric (vs = 519 cm-1) and asymmetric (vas = 747 cm-1) vibrational modes in the castor stearoyl-ACP delta 9 desaturase, which are typical of oxo-bridged diiron clusters. These frequencies shift by -18 and -34 cm-1, respectively, in H218O, proving that the bridging ligand is readily exchangeable with solvent (t1/2 = 7 min). Calculation of an approximately 123 degrees Fe-O-Fe angle from the position of vs and vas and from the 18O-dependent shift in these frequencies suggests that the diiron-oxo cluster in the desaturase is triply bridged in the diferric state. In the diferrous state, the two iron sites of the cluster are structurally inequivalent, as shown by differential temperature dependence of the Mössbauer quadrupole splittings. For the class II diiron-oxo proteins, primary sequence alignments reveal conserved amino acid residues which act as iron cluster ligands, participate in a hydrogen-bonding network, and are potentially involved in O2 binding and activation. Based on this conservation, a structural model for the stearoyl-ACP delta 9 desaturase active site is proposed that has strong similarity to both ribonucleotide reductase and methane monooxygenase. However, after single turnover of the diferous state with 18O2, 18O is not detected in the oxo bridge of the castor desaturase. This is in contrast to the outcome observed for ribonucleotide reductase, suggesting the desaturase and ribonucleotide reductase differ in certain aspects of their respective O2-activation reactions.
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Affiliation(s)
- B G Fox
- Institute for Enzyme Research, Graduate School, University of Wisconsin, Madison 53705
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Shanklin J, Whittle E, Fox BG. Eight histidine residues are catalytically essential in a membrane-associated iron enzyme, stearoyl-CoA desaturase, and are conserved in alkane hydroxylase and xylene monooxygenase. Biochemistry 1994; 33:12787-94. [PMID: 7947684 DOI: 10.1021/bi00209a009] [Citation(s) in RCA: 536] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The eukaryotic fatty acid desaturases are iron-containing enzymes that catalyze the NAD-(P)H- and O2-dependent introduction of double bonds into methylene-interrupted fatty acyl chains. Examination of deduced amino acid sequences for the membrane desaturases from mammals, fungi, insects, higher plants, and cyanobacteria has revealed three regions of conserved primary sequence containing HX(3 or 4)H,HX(2 or 3)HH, and HX(2 or 3)HH. This motif is also present in the bacterial membrane enzymes alkane hydroxylase (omega-hydroxylase) and xylene monooxygenase. Hydropathy analyses indicate that these enzymes contain up to three long hydrophobic domains which would be long enough to span the membrane bilayer twice. The conserved His-containing regions have a consistent positioning with respect to these potential membrane spanning domains. Taken together, these observations suggest that the membrane fatty acid desaturases and hydrocarbon hydroxylases have a related protein fold, possibly arising from a common ancestral origin. In order to examine the functional role of these conserved His residues, we have made use of the ability of the rat delta 9 desaturase gene to complement a yeast strain deficient in the delta 9 desaturase gene function (ole1). By site-directed mutagenesis, eight conserved His residues in the rat delta 9 desaturase were individually converted to Ala. Each His-->Ala mutation failed to complement the yeast ole1 mutant. In contrast, mutation of three nonconserved flanking His residues or a partially conserved Arg residue within the conserved motif to Ala allowed for complementation of the ole1 phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Shanklin
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973
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Affiliation(s)
- P K Stumpf
- Section on Molecular and Cellular Biology, University of California, Davis 95616
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21
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Cahoon EB, Shanklin J, Ohlrogge JB. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco. Proc Natl Acad Sci U S A 1992; 89:11184-8. [PMID: 1454797 PMCID: PMC50514 DOI: 10.1073/pnas.89.23.11184] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Little is known about the metabolic origin of petroselinic acid (18:1 delta 6cis), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the delta 9-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and delta 4-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase.
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Affiliation(s)
- E B Cahoon
- Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824
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22
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A comparison of the major lipid classes and fatty acid composition of marine unicellular cyanobacteria with freshwater species. Arch Microbiol 1991. [DOI: 10.1007/bf00248602] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Smith MA, Cross AR, Jones OT, Griffiths WT, Stymne S, Stobart K. Electron-transport components of the 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (delta 12-desaturase) in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons. Biochem J 1990; 272:23-9. [PMID: 2264826 PMCID: PMC1149651 DOI: 10.1042/bj2720023] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The major cytochrome in microsomal membrane preparations from developing seeds of safflower (Carthamus tinctorius, var High Linoleate), has a reduced-minus-oxidized difference spectrum characteristic of a b-type cytochrome, and was identified from its midpoint-potential (E'7.2) value as cytochrome b5. Cytochromes P-450 and P-420 were also present. The cytochrome b5 content of microsomal preparations from a number of oilseed species was found to be in the order of 200-300 pmol/mg of protein. The cytochrome b5 was reduced in the membrane preparations by NADH, demonstrating the presence of an NADH: cytochrome b5 reductase; NADPH was a less effective donor. Microsomal membranes catalysed the NAD(P)H-dependent conversion of radioactive oleate into linoleate, indicating acyl-CoA: lysophosphatidylcholine acyltransferase and 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (delta 12-desaturase) activity. Desaturation of oleate to linoleate was unaffected by CO, but inhibited by CN-. The addition of oleoyl-CoA to the NADH-reduced membranes resulted in the CN(-)-sensitive partial re-oxidation of cytochrome b5, indicating that electrons from NADH were transferred to the site of desaturation via this cytochrome. The delta 12-desaturase in safflower, therefore, is CN(-)-sensitive and appears to require cytochrome b5 and NADH: cytochrome b5 reductase for activity.
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Affiliation(s)
- M A Smith
- Department of Botany, University of Bristol, U.K
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24
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Guerra DJ, Browse JA. Escherichia coli beta-hydroxydecanoyl thioester dehydrase reacts with native C10 acyl-acyl-carrier proteins of plant and bacterial origin. Arch Biochem Biophys 1990; 280:336-45. [PMID: 2195995 DOI: 10.1016/0003-9861(90)90339-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
beta-Hydroxydecanoyl-[acyl-carrier-protein] dehydrase catalyzes the essential step in the formation of unsaturated fatty acids in Escherichia coli. This reaction was characterized with native C10 acyl-acyl-carrier protein (ACP) structures in both an aqueous phase system and a substrate immobilization assay system. The dehydrase is equally active with E. coli ACP, recombinant ACP-I derived from spinach, or protein A:ACP-I fusion (acyl-thioesters). There were differences among the substrates in terms of the equilibrium product distribution. Both E. coli acyl-ACP and recombinant acyl-ACP-I as cosubstrates with beta-OH 10:0, trans-2 10:1, or cis-3 10:1 yielded about equal amounts (37 mol%) of the two monoenes regardless of the initial substrate. In contrast, the fusion acyl-ACP-I yielded only 17 mol% cis-3 10:1 with 49 mol% trans-2 10:1 present at equilibrium. These equilibrium values for native cis-3 10:1 are higher than those reported previously for the dehydrase using N-acetylcysteamine thioesters as substrates. The Km values for each beta-OH 10:0 ACP substrate were similar to each other and within the range of in vivo concentrations (5-10 microM). Dehydrase reactivity depends more on acyl chain length than ACP structure or origin and is therefore different from other branch point ACP-utilizing enzymes (plant and bacterial) which discriminate according to ACP structure (D. J. Guerra, J. B. Ohlrogge, and M. Frentzen, 1986, Plant Physiol. 82, 448-453).
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Affiliation(s)
- D J Guerra
- Institute of Biological Chemistry, Washington State University, Pullman 99164-6340
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25
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Mayer MP, Beyer P, Kleinig H. Quinone compounds are able to replace molecular oxygen as terminal electron acceptor in phytoene desaturation in chromoplasts of Narcissus pseudonarcissus L. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 191:359-63. [PMID: 2384084 DOI: 10.1111/j.1432-1033.1990.tb19130.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The desaturation of phytoene to zeta-carotene and of zeta-carotene to lycopene employs molecular oxygen as the terminal electron acceptor. 2,3,5,6-Tetramethyl-1,4-benzoquinone (duroquinone) and other artificial quinones are able to replace oxygen, which demonstrates that oxygen does not act in a mixed-function oxygenase-like mechanism at the desaturase itself, but at a spatially separate site. Evidence for additional redox elements mediating between desaturase and oxygen is presented.
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Affiliation(s)
- M P Mayer
- Institut für Biologie II, Universität Freiburg, Federal Republic of Germany
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26
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Koll M, Erwin JA. The effect of dietary sterol on the activity of fatty acid desaturases isolated from Tetrahymena setosa. THE JOURNAL OF PROTOZOOLOGY 1990; 37:229-37. [PMID: 2359050 DOI: 10.1111/j.1550-7408.1990.tb01133.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Tetrahymena setosa has a nutritional requirement for micro amounts of sterol, a requirement which is also satisfied by relatively large amounts of either intact phospholipids or a mixture of unsaturated fatty acids normally found in these ciliates. Three microsomal fatty acyl-CoA desaturases have been isolated from T. setosa and partially characterized. These enzymes which can account for the formation of the majority of the ciliate's unsaturated fatty acids, include: a delta 9, a delta 12 and a delta 6 desaturase which catalyze the transformation of stearoyl-CoA to oleic acid, of oleoyl-CoA to linoleic acid and of linoleoyl-CoA to gamma-linolenic acid, respectively. The stearoyl CoA desaturase required NAD (or NADP), ATP and free CoA; the delta 6 and delta 12 desaturases required NADP, but not ATP or CoA. Cellular levels of the three desaturases were highest in mid-logarithmic phase cells and lowest in stationary phase cells. In order to determine if there was a relationship between the sterol requirement and the ability of the organism to desaturate, T. setosa was grown in a synthetic medium supplemented with either cholesterol or a phospholipid which permits growth in the absence of cholesterol, or with both phospholipid and cholesterol. Cells grown with phospholipid alone had only half as much stearoyl-CoA and oleoyl-CoA desaturase activity as cells of identical culture age grown either on cholesterol alone or on cholesterol plus phospholipid.
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Affiliation(s)
- M Koll
- Chicago Board of Health, Daley Center, Illinois 60602
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27
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Enzymes of Fatty Acid Synthesis. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/b978-0-12-461013-2.50018-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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28
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Beyer P, Mayer M, Kleinig H. Molecular oxygen and the state of geometric isomerism of intermediates are essential in the carotene desaturation and cyclization reactions in daffodil chromoplasts. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 184:141-50. [PMID: 2776764 DOI: 10.1111/j.1432-1033.1989.tb15000.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The membrane-bound carotenogenic reaction sequence in daffodil chromoplasts can be subdivided in vitro into three reaction segments by varying the incubation parameters O2 and light. In the first segment, 15-cis-phytoene is desaturated to 15-cis-zeta-carotene (trans elimination of hydrogen) in the dark and in the presence of O2 as an essential cofactor. A photoisomerization of the 15-cis double bond of the accumulated zeta-carotene to trans is the prerequisite for the function of the second segment, the desaturation to 7,9,9',7'-tetra-cis-lycopene (prolycopene, cis elimination of hydrogen). The role of O2 as an electron acceptor is discussed and evidence for an oxidoreductase acting as a redox mediator between the desaturase (forming the polyene chromophore) and O2 is presented. A certain analogy to the desaturation of stearoyl-carrier protein, which also occurs in plastids, is proposed. The third segment, the cyclization of prolycopene, is active only in the absence of O2 and involves additional cis-trans isomerization reactions.
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Affiliation(s)
- P Beyer
- Institut für Biologie II, Zellbiologie, Universität Freiburg, Federal Republic of Germany
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29
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Andrews J, Schmidt H, Heinz E. Interference of electron transport inhibitors with desaturation of monogalactosyl diacylglycerol in intact chloroplasts. Arch Biochem Biophys 1989; 270:611-22. [PMID: 2650625 DOI: 10.1016/0003-9861(89)90544-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Isolated intact chloroplasts are able to desaturate fatty acids in newly synthesized monogalactosyl diacylglycerol. By analogy with other systems, this desaturation might be expected to involve electron carriers. The effects of electron transport inhibitors on chloroplast lipid-linked desaturation were therefore investigated. Because desaturation occurs in the dark and is not inhibited by compounds specifically blocking photosystem II, it appeared that the photosystems themselves did not participate. Several compounds that prevent enzymatic reoxidation of plastoquinol in thylakoid membranes at the Qz site or withdraw electrons from this lipophilic electron carrier inhibited desaturation in the dark. This inhibition could not be reversed by adding chemicals that donate electrons to photosystem I, indicating that carriers past the cytochrome b/f complex were not involved. Inhibitors of cyclic electron transport interfered with desaturation only at rather high concentrations or not at all. Additional compounds that block the reduction of quinones were slightly inhibitory. Dithioerythritol and KCN also inhibited desaturation, although their exact mode of action is unknown. Dinitrophenyl-iodonitrothymol (DNP-INT), stigmatellin, and myxothiazol did not block desaturation at concentrations that inhibited photosynthetic electron flow through the Qz site very efficiently. Therefore, these results argue against an involvement of the Qz site in desaturation. Accordingly, the inhibition by the other compounds seemingly interfering at the same site as well as that by electron acceptors could be due to interference at a different redox step in desaturation. In vitro these compounds function also as electron acceptors in diaphorase reactions catalyzed by ferredoxin:NADP oxidoreductase.
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Affiliation(s)
- J Andrews
- Institut für Allgemeine Botanik, Universität Hamburg, Federal Republic of Germany
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30
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Browse J, Slack CR. Fatty-acid synthesis in plastids from maturing safflower and linseed cotyledons. PLANTA 1985; 166:74-80. [PMID: 24241314 DOI: 10.1007/bf00397388] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/1985] [Accepted: 05/06/1985] [Indexed: 05/25/2023]
Abstract
Plastids isolated from maturing, nongreen safflower (Carthamus tinctorius L.) cotyledons yielded unesterified fatty acids as the predominant product of fatty-acid synthesis from [1-(14)C]acetate. Exogenous reduced pyridine nucleotides were not required for this synthesis, but [1-(14)C]acetate incorporation was absolutely dependent on addition of ATP. Linseed (Linum usitatissimum L.) cotyledons are green during development and plastids isolated from them resembled leaf chloroplasts with developed grana. In contrast to the safflower plastids, those from linseed were able to carry out fatty-acid synthesis at low irradiances without the addition of either pyridine nucleotides or ATP. Intact linseed cotyledons were capable of net photosynthesis at rates up to 95 μmol·mg(-1) chlorophyll·h(-1). However, the low-light environment inside the linseed capsule (approx. 15% of external) means that photosynthesis will not contribute appreciably to the carbon economy of the developing seed and its main role may be to supply cofactors for fatty-acid synthesis.
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Affiliation(s)
- J Browse
- Plant Physiology Division, Department of Scientific and Industrial Research, Private Bag, Palmerston North, New Zealand
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31
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Abstract
Acyl carrier protein (ACP) from spinach leaves has been purified to homogeneity by high-performance liquid chromatography with an anion-exchange column. The amino acid sequence of one major ACP in spinach leaves, ACP-I, has been determined by automated Edman degradation. It consists of the following 82 amino acids: (sequence in text). Sequencing of the intact polypeptide provided data for the first 57 residues. Cleavage of the succinylated ACP with CNBr at Met-46, followed by sequencing of the fragment mixture, provided data for the final 36 residues. The C-terminal alanine was confirmed by carboxypeptidase Y digestion. The spinach ACP has 40, 70, and 25% homology with Escherichia coli, barley, and rabbit ACPs, respectively. The results not only provide the first complete sequence of a plant ACP, but also provide insight into the structural and evolutionary relationships among plant, animal, and bacterial ACPs.
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Abstract
The effect of hypolipidemic drugs, WY14643 and DH990, on plant lipid metabolism has been studied. The total incorporation of [14C]acetate into lipids was inhibited by addition of both drugs to aged potato (Solanum tuberosum) tuber discs, spinach (Spinacia oleracea) leaves, and spinach chloroplasts, while the incorporation in Chlorella vulgaris cells was affected only by DH990. Moreover, DH990 inhibited the incorporation of 14C-labeled fatty acids into phosphatidylcholine and phosphatidylethanolamine of potato discs, and decreased the incorporation into phosphatidylglycerol of Chlorella cells. DH990 inhibited the formation of polyunsaturated fatty acids in potato discs, Chlorella cells, and spinach leaves, whereas WY14643 had no effect on the formation of these fatty acids. Stearoyl-ACP desaturase from safflower (Carthamus tinctorius) seeds was very sensitive to both drugs, especially DH990, which completely blocked the activity at 2 mM levels. When safflower lysophospholipid acyltransferases were solubilized by detergent treatment, only DH990 inhibited the incorporation of [14C]oleoyl-CoA into lysophosphatidylcholine or lysophosphatidylethanolamine. Both drugs inhibited fatty acid synthesis from [14C]malonyl-CoA in the microsomal fraction from safflower seeds, but only DH990 inhibited FAS activity in the soluble fraction; both drugs inhibited severely the formation of stearic acid. Both acetyl-CoA carboxylase and acetyl-CoA synthetase were sensitive to both drugs.
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R. Stapleton S, Jaworski JG. Characterization of fatty acid biosynthesis in the cyanobacterium Anabaena variabilis. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0005-2760(84)90152-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Characterization and purification of malonyl-coenzyme A:[acyl-carrier-protein] transacylases from spinach and Anabaena variabilis. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0005-2760(84)90151-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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35
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Chapter 6 Fatty acid biosynthesis in higher plants. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0167-7306(08)60124-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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36
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Abstract
So far, reviews that have appeared on fungal lipids present data mainly on the lipid composition of these organisms and the influence of lipids on their physiology. These reviews provide little information about the enzymes of lipid metabolism in these organisms and it is assumed, by most workers, that lipid synthesis in all fungi takes place as in Saccharomyces cervesiae, the only fungus in which the complete pathways of phospholipid biosynthesis have been worked out. During the last few years, literature has accumulated on lipid metabolic enzymes of other fungi, as investigators became increasingly interested in this area of research. The present review, after an introduction, will be divided into different sections and each section will deal, comparatively, with various aspects of fungal lipid metabolism and physiology. This review will, therefore, bring out the differences or similarities of lipid metabolism in diverse fungal species.
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37
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Tissue culture of cocoa bean (Theobroma cacao L.): Incorporation of fatty acids into lipids of cultured cells. Lipids 1982; 17:848-52. [DOI: 10.1007/bf02534577] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/1982] [Indexed: 11/30/2022]
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38
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McKeon TA, Stumpf PK. Purification and characterization of the stearoyl-acyl carrier protein desaturase and the acyl-acyl carrier protein thioesterase from maturing seeds of safflower. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33690-1] [Citation(s) in RCA: 197] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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39
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Uda M, Shiojima K, Shigematsu H, Singh I, Kishimoto Y. Purification of the heat-stable factor required for alpha-hydroxylation and beta-oxidation of very long chain fatty acids in brain. Arch Biochem Biophys 1982; 216:186-95. [PMID: 7103506 DOI: 10.1016/0003-9861(82)90203-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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40
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41
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Abstract
The particulate fraction, heat-labile factor, heat-stable factor, and NADPH are essential for the conversion of lignoceric acid (tetracosanoic acid) to cerebronic acid (alpha-hydroxylignoceric acid). The heat-labile factor was extracted from calf cerebellum and partially purified in four steps: ammonium sulfate precipitation, hydroxylapatite chromatography, isoelectric focusing, and NAD-Agarose affinity chromatography. The specific activity of the heat-labile factor was increased 105-fold during the last three steps, with a yield of 37% of the activity. One major and several minor bands were visible when the preparation was examined by SDS-polyacrylamide gel electrophoresis with Coomassie blue staining. The major band corresponded to a protein of molecular weight 32,700, and the minor bands corresponded to proteins of molecular weights 62,000 and 67,000. The activity was lost when the heat-labile factor was incubated with 1 mM-N-ethylmaleimide. This inhibition was prevented by preincubating the heat-labile factor with 1 mM-NADH. These observations indicate that the heat-labile factor contains a sulfhydryl group which is essential for activity, and that it is located at or near the binding site for the pyridine nucleotide.
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Jones AV, Harwood JL, Stratford MR, Stumpf PK. Inhibition of plant fatty acid synthesis by nitroimidazoles. Biochem J 1981; 198:193-8. [PMID: 7325993 PMCID: PMC1163226 DOI: 10.1042/bj1980193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
1. The effect of the addition of a number of nitroimidazoles was tested on fatty acid synthesis by germinating pea seeds, isolated lettuce chloroplasts and a soluble fraction from pea seeds. 2. All the compounds tested had a marked inhibition on stearate desaturation by lettuce chloroplasts and on the synthesis of very-long-chain fatty acids by pea seeds. 3. In contrast, the effect of the drugs on total fatty acid synthesis from [14C]acetate in chloroplasts was related to the compound's electron reduction potentials. 4. Of the compounds used, only metronidazole had a marked inhibition on palmitate elongation in the systems tested. 5. The mechanism of inhibition of plant fatty acid synthesis by nitroimidazoles is discussed and the possible relevance of these findings to their neurotoxicity is suggested.
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Moreau RA, Pollard MR, Stumpf PK. Properties of a delta 5-fatty acyl-CoA desaturase in the cotyledons of developing Limnanthes alba. Arch Biochem Biophys 1981; 209:376-84. [PMID: 7294800 DOI: 10.1016/0003-9861(81)90295-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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44
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[34] Stearoyl-acyl carrier protein desaturase from safflower seeds. Methods Enzymol 1981. [DOI: 10.1016/0076-6879(81)71036-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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45
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Abstract
The synthesis of fatty acids from [14C]malonyl-CoA was studied with a high-speed particulate fraction from germinating pea (Pisum sativum). The variety used (Feltham First) produced mainly saturated fatty acids with palmitate (30--40%) and stearate (40--60%) predominating. Several palmitate-containing lipids stimulated overall synthesis and, in addition, increased the percentage of label in stearate. The production of stearate was severely inhibited by preincubation of the microsomal fraction with snake venom phospholipase A2 or by incubation with Rhizopus arrhizus lipase. Addition of a series of di-saturated phosphatidylcholines, with different acyl constituents, resulted in stimulation of overall fatty acid synthesis as well as an increase in the radiolabelling of the fatty acid two carbon atoms longer than the acyl chain added. This chain lengthening of fatty acids donated from phosphatidylcholine was due to the action of both fatty acid synthetase and palmitate elongase. The latter would utilize dipalmitoyl phosphatidylcholine and was sensitive to arsenite whereas fatty acid synthetase would use dilauroyl phosphatidylcholine and was sensitive to cerulenin. The results are discussed in relation to previous data obtained in vivo on plant fatty acid synthesis and current suggestions for the role of phosphatidylcholine in this process.
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46
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Singh I, Kishimoto Y. Ceramide synthesis in rat brain: characterization of the synthesis requiring pyridine nucleotide. Arch Biochem Biophys 1980; 202:93-100. [PMID: 7396538 DOI: 10.1016/0003-9861(80)90409-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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48
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Pollard MR, McKeon T, Gupta LM, Stumpf PK. Studies on biosynthesis of waxes by developing jojoba seed. II. the demonstration of wax biosynthesis by cell-free homogenates. Lipids 1979. [DOI: 10.1007/bf02533451] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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49
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Lessire R, Cassagne C. Direct synthesis of stearoyl-acyl carrier protein from stearate by microsomes from Allium porrum epidermal cells. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/0304-4211(79)90152-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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50
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Quinn PJ, Williams WP. Plant lipids and their role in membrane function. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1979; 34:109-73. [PMID: 375299 DOI: 10.1016/0079-6107(79)90016-6] [Citation(s) in RCA: 133] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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