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Zhou Q, Zheng C, Wei F, Yang Y. Flavor precursors identification and thermal degradation mechanisms of glucoerucin in fragrant rapeseed oil. Food Chem 2024; 435:137484. [PMID: 37778265 DOI: 10.1016/j.foodchem.2023.137484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023]
Abstract
The degradation products of glucosinolates endow rapeseed oil with a characteristic aroma, however, the mechanism remains unclear. In this study, 29 individual glucosinolates were identified in six rapeseeds (Brassica napus) using widely targeted metabolism, including 22 aliphatic, 5 aromatic, and 2 indole glucosinolates. Characterization of thermally induced aromas from new precursors-glucoerucin was performed in different pH matrices via headspace-solid phase microextraction and gas chromatography-mass spectrometry. Six glucoerucin degradation were identified including 5-methylthio-pentanenitrile and dimethyl trisulfide et al. The results of thermal model showed that Glucoerucin could generate volatile 5-methylthio-pentanenitrile via dehydration and formed 1-isothiocyanato-4-(methylsulfanyl)butane via (394.9 μg/kg) by the Rosen rearrangement further product pungent odors 4-isothiocyanato-1-butene (5.6 μg/kg) at pH 5. Sulfur-containing compounds included dimethyl disulfide and dimethyl trisulfide can provide pungent and cabbage notes in matrices at pH 7 and 9. The results provide a new understanding in the forming mechanism of characteristic odor in fragrant rapeseed oil.
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Affiliation(s)
- Qi Zhou
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan, 430062, China.
| | - Chang Zheng
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan, 430062, China
| | - Fang Wei
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan, 430062, China
| | - Yini Yang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan, 430062, China
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Hashemi Haeri H, Schneegans N, Eisenschmidt-Bönn D, Brandt W, Wittstock U, Hinderberger D. Characterization of the active site in the thiocyanate-forming protein from Thlaspi arvense (TaTFP) using EPR spectroscopy. Biol Chem 2024; 405:105-118. [PMID: 37586381 DOI: 10.1515/hsz-2023-0187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 07/19/2023] [Indexed: 08/18/2023]
Abstract
Glucosinolates are plant thioglucosides, which act as chemical defenses. Upon tissue damage, their myrosinase-catalyzed hydrolysis yields aglucones that rearrange to toxic isothiocyanates. Specifier proteins such as thiocyanate-forming protein from Thlaspi arvense (TaTFP) are non-heme iron proteins, which capture the aglucone to form alternative products, e.g. nitriles or thiocyanates. To resolve the electronic state of the bound iron cofactor in TaTFP, we applied continuous wave electron paramagnetic resonance (CW EPR) spectroscopy at X-and Q-band frequencies (∼9.4 and ∼34 GHz). We found characteristic features of high spin and low spin states of a d 5 electronic configuration and local rhombic symmetry during catalysis. We monitored the oxidation states of bound iron during conversion of allylglucosinolate by myrosinase and TaTFP in presence and absence of supplemented Fe2+. Without added Fe2+, most high spin features of bound Fe3+ were preserved, while different g'-values of the low spin part indicated slight rearrangements in the coordination sphere and/or structural geometry. We also examined involvement of the redox pair Fe3+/Fe2 in samples with supplemented Fe2+. The absence of any EPR signal related to Fe3+ or Fe2+ using an iron-binding deficient TaTFP variant allowed us to conclude that recorded EPR signals originated from the bound iron cofactor.
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Affiliation(s)
- Haleh Hashemi Haeri
- Martin Luther University Halle-Wittenberg, Institute of Chemistry, Von-Danckelmann-Platz 4, D-06120 Halle (Saale), Germany
| | - Nicola Schneegans
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Daniela Eisenschmidt-Bönn
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Wolfgang Brandt
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Ute Wittstock
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Dariush Hinderberger
- Martin Luther University Halle-Wittenberg, Institute of Chemistry, Von-Danckelmann-Platz 4, D-06120 Halle (Saale), Germany
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3
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Mocniak LE, Elkin K, Bollinger JM. Lifetimes of the Aglycone Substrates of Specifier Proteins, the Autonomous Iron Enzymes That Dictate the Products of the Glucosinolate-Myrosinase Defense System in Brassica Plants. Biochemistry 2020; 59:2432-2441. [PMID: 32516526 DOI: 10.1021/acs.biochem.0c00358] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Specifier proteins (SPs) are components of the glucosinolate-myrosinase defense system found in plants of the order Brassicales (brassicas). Glucosinolates (GLSs) comprise at least 150 known S-(β-d-glucopyranosyl)thiohydroximate-O-sulfonate compounds, each with a distinguishing side chain linked to the central carbon. Following tissue injury, the enzyme myrosinase (MYR) promiscuously hydrolyzes the common thioglycosidic linkage of GLSs to produce unstable aglycone intermediates, which can readily undergo a Lossen-like rearrangement to the corresponding organoisothiocyanates. The known SPs share a common protein architecture but redirect the breakdown of aglycones to different stable products: epithionitrile (ESP), nitrile (NSP), or thiocyanate (TFP). The different effects of these products on brassica consumers motivate efforts to understand the defense response in chemical detail. Experimental analysis of SP mechanisms is challenged by the instability of the aglycones and would be facilitated by knowledge of their lifetimes. We developed a spectrophotometric method that we used to monitor the rearrangement reactions of the MYR-generated aglycones from nine GLSs, discovering that their half-lives (t1/2) vary by a factor of more than 50, from <3 to 150 s (22 °C). The t1/2 of the sinigrin-derived allyl aglycone (34 s), which can form the epithionitrile product (1-cyano-2,3-epithiopropane) in the presence of ESP, proved to be sufficient to enable spatial and temporal separation of the MYR and ESP reactions. The results confirm recent proposals that ESP is an autonomous iron-dependent enzyme that intercepts the unstable aglycone rather than a direct effector of MYR. Knowledge of aglycone lifetimes will enable elucidation of how the various SPs reroute aglycones to different products.
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Affiliation(s)
| | - Kyle Elkin
- Pasture Systems and Watershed Management Research Unit, United States Department of Agriculture Agricultural Research Service, Building 3702 Curtin Road, University Park, Pennsylvania 16802, United States
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Román J, González D, Inostroza-Ponta M, Mahn A. Molecular Modeling of Epithiospecifier and Nitrile-Specifier Proteins of Broccoli and Their Interaction with Aglycones. Molecules 2020; 25:molecules25040772. [PMID: 32054008 PMCID: PMC7071048 DOI: 10.3390/molecules25040772] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/24/2022] Open
Abstract
Glucosinolates are secondary plant metabolites of Brassicaceae. They exert their effect after enzymatic hydrolysis to yield aglycones, which become nitriles and epithionitriles through the action of epithiospecifier (ESP) and nitrile-specifier proteins (NSP). The mechanism of action of broccoli ESP and NSP is poorly understood mainly because ESP and NSP structures have not been completely characterized and because aglycones are unstable, thus hindering experimental measurements. The aim of this work was to investigate the interaction of broccoli ESP and NSP with the aglycones derived from broccoli glucosinolates using molecular simulations. The three-dimensional structure of broccoli ESP was built based on its amino-acid sequence, and the NSP structure was constructed based on a consensus amino-acid sequence. The models obtained using Iterative Threading ASSEmbly Refinement (I-TASSER) were refined with the OPLS-AA/L all atom force field of GROMACS 5.0.7 and were validated by Veryfy3D and ERRAT. The structures were selected based on molecular dynamics simulations. Interactions between the proteins and aglycones were simulated with Autodock Vina at different pH. It was concluded that pH determines the stability of the complexes and that the aglycone derived from glucoraphanin has the highest affinity to both ESP and NSP. This agrees with the fact that glucoraphanin is the most abundant glucosinolate in broccoli florets.
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Affiliation(s)
- Juan Román
- Departamento de Ingeniería Química, Universidad de Santiago de Chile, Avenida Libertador Bernardo O’Higgins 3363, Estación Central, Santiago 9170019, Chile; (J.R.); (D.G.)
| | - Dorian González
- Departamento de Ingeniería Química, Universidad de Santiago de Chile, Avenida Libertador Bernardo O’Higgins 3363, Estación Central, Santiago 9170019, Chile; (J.R.); (D.G.)
| | - Mario Inostroza-Ponta
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Avenida Libertador Bernardo O’Higgins 3363, Estación Central, Santiago 9170019, Chile;
| | - Andrea Mahn
- Departamento de Ingeniería Química, Universidad de Santiago de Chile, Avenida Libertador Bernardo O’Higgins 3363, Estación Central, Santiago 9170019, Chile; (J.R.); (D.G.)
- Correspondence: ; Tel.: +56-2-2718-1833
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Blažević I, Montaut S, Burčul F, Olsen CE, Burow M, Rollin P, Agerbirk N. Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants. PHYTOCHEMISTRY 2020; 169:112100. [PMID: 31771793 DOI: 10.1016/j.phytochem.2019.112100] [Citation(s) in RCA: 237] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 07/04/2019] [Accepted: 08/18/2019] [Indexed: 05/05/2023]
Abstract
The glucosinolates (GSLs) is a well-defined group of plant metabolites characterized by having an S-β-d-glucopyrano unit anomerically connected to an O-sulfated (Z)-thiohydroximate function. After enzymatic hydrolysis, the sulfated aglucone can undergo rearrangement to an isothiocyanate, or form a nitrile or other products. The number of GSLs known from plants, satisfactorily characterized by modern spectroscopic methods (NMR and MS) by mid-2018, is 88. In addition, a group of partially characterized structures with highly variable evidence counts for approximately a further 49. This means that the total number of characterized GSLs from plants is somewhere between 88 and 137. The diversity of GSLs in plants is critically reviewed here, resulting in significant discrepancies with previous reviews. In general, the well-characterized GSLs show resemblance to C-skeletons of the amino acids Ala, Val, Leu, Trp, Ile, Phe/Tyr and Met, or to homologs of Ile, Phe/Tyr or Met. Insufficiently characterized, still hypothetic GSLs include straight-chain alkyl GSLs and chain-elongated GSLs derived from Leu. Additional reports (since 2011) of insufficiently characterized GSLs are reviewed. Usually the crucial missing information is correctly interpreted NMR, which is the most effective tool for GSL identification. Hence, modern use of NMR for GSL identification is also reviewed and exemplified. Apart from isolation, GSLs may be obtained by organic synthesis, allowing isotopically labeled GSLs and any kind of side chain. Enzymatic turnover of GSLs in plants depends on a considerable number of enzymes and other protein factors and furthermore depends on GSL structure. Identification of GSLs must be presented transparently and live up to standard requirements in natural product chemistry. Unfortunately, many recent reports fail in these respects, including reports based on chromatography hyphenated to MS. In particular, the possibility of isomers and isobaric structures is frequently ignored. Recent reports are re-evaluated and interpreted as evidence of the existence of "isoGSLs", i.e. non-GSL isomers of GSLs in plants. For GSL analysis, also with MS-detection, we stress the importance of using authentic standards.
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Affiliation(s)
- Ivica Blažević
- Department of Organic Chemistry, Faculty of Chemistry and Technology, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia.
| | - Sabine Montaut
- Department of Chemistry and Biochemistry, Biomolecular Sciences Programme, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
| | - Franko Burčul
- Department of Analytical Chemistry, Faculty of Chemistry and Technology, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia
| | - Carl Erik Olsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Meike Burow
- DynaMo Center and Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Patrick Rollin
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR 7311, BP 6759, F-45067, Orléans Cedex 2, France
| | - Niels Agerbirk
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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Eisenschmidt‐Bönn D, Schneegans N, Backenköhler A, Wittstock U, Brandt W. Structural diversification during glucosinolate breakdown: mechanisms of thiocyanate, epithionitrile and simple nitrile formation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:329-343. [PMID: 30900313 PMCID: PMC6850609 DOI: 10.1111/tpj.14327] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 05/20/2023]
Abstract
Secondary metabolism is characterized by an impressive structural diversity. Here, we have addressed the mechanisms underlying structural diversification upon damage-induced activation of glucosinolates, a group of thioglucosides found in the Brassicales. The classical pathway of glucosinolate activation involves myrosinase-catalyzed hydrolysis and rearrangement of the aglucone to an isothiocyanate. Plants of the Brassicaceae possess specifier proteins, i.e. non-heme iron proteins that promote the formation of alternative products by interfering with this reaction through unknown mechanisms. We have used structural information available for the thiocyanate-forming protein from Thlaspi arvense (TaTFP), to test the impact of loops protruding at one side of its β-propeller structure on product formation using the allylglucosinolate aglucone as substrate. In silico loop structure sampling and semiempirical quantum mechanical calculations identified a 3L2 loop conformation that enabled the Fe2+ cofactor to interact with the double bond of the allyl side chain. Only this arrangement enabled the formation of allylthiocyanate, a specific product of TaTFP. Simulation of 3,4-epithiobutane nitrile formation, the second known product of TaTFP, required an alternative substrate docking arrangement in which Fe2+ interacts with the aglucone thiolate. In agreement with these results, substitution of 3L2 amino acid residues involved in the conformational change as well as exchange of critical amino acid residues of neighboring loops affected the allylthiocyanate versus epithionitrile proportion obtained upon myrosinase-catalyzed allylglucosinolate hydrolysis in the presence of TaTFP in vitro. Based on these insights, we propose that specifier proteins are catalysts that might be classified as Fe2+ -dependent lyases.
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Affiliation(s)
- Daniela Eisenschmidt‐Bönn
- Department of Bioorganic ChemistryLeibniz Institute of Plant BiochemistryWeinberg 306120Halle (Saale)Germany
| | - Nicola Schneegans
- Institute of Pharmaceutical BiologyTechnische Universität BraunschweigMendelssohnstr. 138106BraunschweigGermany
| | - Anita Backenköhler
- Institute of Pharmaceutical BiologyTechnische Universität BraunschweigMendelssohnstr. 138106BraunschweigGermany
| | - Ute Wittstock
- Institute of Pharmaceutical BiologyTechnische Universität BraunschweigMendelssohnstr. 138106BraunschweigGermany
| | - Wolfgang Brandt
- Department of Bioorganic ChemistryLeibniz Institute of Plant BiochemistryWeinberg 306120Halle (Saale)Germany
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Identification Of N-Acetyl- S-(3-Cyano-2-(Methylsulfanyl)Propyl-Cysteine as a Major Human Urine Metabolite from the Epithionitrile 1-Cyano-2,3-Epithiopropane, the Main Glucosinolate Hydrolysis Product from Cabbage. Nutrients 2019; 11:nu11040908. [PMID: 31018609 PMCID: PMC6521188 DOI: 10.3390/nu11040908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 11/17/2022] Open
Abstract
Brassica vegetables such as cabbage or pak choi contain alkenyl glucosinolates which can release epithionitriles and to a lesser degree isothiocyanates upon enzymatic hydrolysis. Here, for the first time, the metabolism of an epithionitrile was investigated in humans, namely 1-cyano-2,3-epithiopropane (CETP). After consumption of Brassica oleracea var. capitata f. alba and Brassica carinata sprouts, the main urinary metabolite of CETP was identified as N-acetyl-S-(3-cyano-2-(methylsulfanyl)propyl-cysteine using an UHPLC-ESI-QToF-MS approach and synthesis of the metabolite. This urinary epithionitrile metabolite is an S-methylated mercapturic acid. No other metabolites were detected. Then, in a preliminary pilot experiment the excretion kinetics of CETP were investigated in three volunteers. After consumption of a B. carinata sprout preparation containing 50.8 µmol of CETP, urinary N-acetyl-S-(3-cyano-2-(methylsulfanyl)propyl-cysteine concentrations were the highest three hours after consumption, ranging from 23.9 to 37.2 µM, and declined thereafter. Thus, epithionitriles are bioavailable compounds that are metabolized similarly to isothiocyanates by the mercapturic acid pathway. In the future, more epithionitrile metabolites should be identified and the pharmacokinetics of these important class of dietary compounds should be assessed in more detail.
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Iron is a centrally bound cofactor of specifier proteins involved in glucosinolate breakdown. PLoS One 2018; 13:e0205755. [PMID: 30395611 PMCID: PMC6218027 DOI: 10.1371/journal.pone.0205755] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/01/2018] [Indexed: 12/14/2022] Open
Abstract
Glucosinolates, a group of sulfur-rich thioglucosides found in plants of the order Brassicales, have attracted a lot of interest as chemical defenses of plants and health promoting substances in human diet. They are accumulated separately from their hydrolyzing enzymes, myrosinases, within the intact plant, but undergo myrosinase-catalyzed hydrolysis upon tissue disruption. This results in various biologically active products, e.g. isothiocyanates, simple nitriles, epithionitriles, and organic thiocyanates. While formation of isothiocyanates proceeds by a spontaneous rearrangement of the glucosinolate aglucone, aglucone conversion to the other products involves specifier proteins under physiological conditions. Specifier proteins appear to act with high specificity, but their exact roles and the structural bases of their specificity are presently unknown. Previous research identified the motif EXXXDXXXH as potential iron binding site required for activity, but crystal structures of recombinant specifier proteins lacked the iron cofactor. Here, we provide experimental evidence for the presence of iron (most likely Fe2+) in purified recombinant thiocyanate-forming protein from Thlaspi arvense (TaTFP) using a Ferene S-based photometric assay as well as Inductively Coupled Plasma-Mass Spectrometry. Iron binding and activity depend on E266, D270, and H274 suggesting a direct interaction of Fe2+ with these residues. Furthermore, we demonstrate presence of iron in epithiospecifier protein and nitrile-specifier protein 3 from Arabidopsis thaliana (AtESP and AtNSP3). We also present a homology model of AtNSP3. In agreement with this model, iron binding and activity of AtNSP3 depend on E386, D390, and H394. The homology model further suggests that the active site of AtNSP3 imposes fewer restrictions to the glucosinolate aglucone conformation than that of TaTFP and AtESP due to its larger size. This may explain why AtNSP3 does not support epithionitrile or thiocyanate formation, which likely requires exact positioning of the aglucone thiolate relative to the side chain.
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Hanschen FS, Pfitzmann M, Witzel K, Stützel H, Schreiner M, Zrenner R. Differences in the enzymatic hydrolysis of glucosinolates increase the defense metabolite diversity in 19 Arabidopsis thaliana accessions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 124:126-135. [PMID: 29366972 DOI: 10.1016/j.plaphy.2018.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/11/2018] [Accepted: 01/11/2018] [Indexed: 05/20/2023]
Abstract
Plants of the order Brassicales produce glucosinolates (GS), a group of secondary metabolites that are part of an elaborate defense system. But it is not the GS itself rather its enzymatic hydrolysis products that cause the bioactive effects protecting the plants against pests and pathogens. Thus the enzymatic hydrolysis and a variety of additional influential factors determine the structural outcome of the GS degradation process. To evaluate the possible diversity of defense metabolites a range of 19 Arabidopsis thaliana accessions were selected showing divergence in their geographical origin, in their phenotype, and in their GS profile. These particular accessions accumulate several alkenyl GS, hydroxyalkyl GS, methylthioalkyl GS, and methylsulfinylalkyl GS in their rosette leaves whereas the indole GS contents are relatively invariant, as analyzed by UHPLC-DAD. After tissue disruption the enzymatic formation of GS hydrolysis products was examined and breakdown products were identified and quantified by GC-MS. Great differences in the amount and structure of volatile enzymatic degradation products could be observed in the different accessions, with strong variation in formation of epithionitriles, nitriles, and isothiocyanates. The occurrence of specific GS hydrolysis products was put in relation to relative gene expression profiles of myrosinases and specifier proteins as measured by RT-qPCR, and in relation to relative protein abundance of epithiospecifier protein. Dependent on the different GS profiles and reliant on degradation protein abundance and composition the ecotypes strongly varied in their ability to form isothiocyanates, nitriles and epithionitriles, thus increasing the plants' equipment of defense metabolites.
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Affiliation(s)
- Franziska S Hanschen
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer Weg 1, 14979 Großbeeren, Germany.
| | - Markus Pfitzmann
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer Weg 1, 14979 Großbeeren, Germany; Leibniz Universität Hannover, Institute of Horticultural Production Systems, Herrenhäuser Straße 2, 30419 Hannover, Germany.
| | - Katja Witzel
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer Weg 1, 14979 Großbeeren, Germany.
| | - Hartmut Stützel
- Leibniz Universität Hannover, Institute of Horticultural Production Systems, Herrenhäuser Straße 2, 30419 Hannover, Germany.
| | - Monika Schreiner
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer Weg 1, 14979 Großbeeren, Germany.
| | - Rita Zrenner
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer Weg 1, 14979 Großbeeren, Germany.
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Zhang W, Zhou Y, Wang K, Dong Y, Wang W, Feng Y. Crystal structure of the nitrile-specifier protein NSP1 from Arabidopsis thaliana. Biochem Biophys Res Commun 2017; 488:147-152. [PMID: 28479247 DOI: 10.1016/j.bbrc.2017.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 01/23/2023]
Abstract
As important components of the glucosinolate-myrosinase system, specifier proteins mediate plant defense against herbivory and pathogen attacks. After tissue disruption, glucosinolates are hydrolyzed by myrosinases to instable aglucones, which will rearrange to form defensive isothiocyanates. Nevertheless, this reaction could be redirected to form other products by specifier proteins. Up to now, identified specifier proteins include epithiospecifier proteins (ESPs), thiocyanate forming proteins (TFPs), and nitrile-specifier proteins (NSPs). Recently, the structures of ESP and TFP have been reported. However, both the structure and the catalytic mechanism of NSPs remain enigmatic. Here, we solved the crystal structure of the NSP1 protein from Arabidopsis thaliana (AtNSP1). Structural comparisons with ESP and TFP proteins revealed several structural features of AtNSP1 different from those of the two proteins. Subsequent molecular docking studies showed that the R292 residue in AtNSP1 displayed a conformation different from those of the corresponding residues in ESP and TFP proteins, which might account for the product specificity and catalytic mechanism of AtNSP1. Taken together, the present study provides important insights into the molecular mechanisms underlying the different product spectrums between NSPs and the other two types of specifier proteins, and shed light on the future studies of the detailed mechanisms of other specifier proteins.
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Affiliation(s)
- Weiwei Zhang
- Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Yu Zhou
- National Institute of Biological Sciences, Beijing, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, PR China
| | - Kan Wang
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Yanan Dong
- Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Wenhe Wang
- Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Yue Feng
- Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, PR China.
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