Brodhun, Florian

[["dc.bibliographiccitation.firstpage","1251"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","PLANT PHYSIOLOGY"],["dc.bibliographiccitation.lastpage","1266"],["dc.bibliographiccitation.volume","160"],["dc.contributor.author","Neumann, Piotr"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Sauer, Kristin"],["dc.contributor.author","Herrfurth, Cornelia"],["dc.contributor.author","Hamberg, Mats"],["dc.contributor.author","Brinkmann, Jens"],["dc.contributor.author","Scholz, Julia"],["dc.contributor.author","Dickmanns, Achim"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Ficner, Ralf"],["dc.date.accessioned","2017-09-07T11:48:22Z"],["dc.date.available","2017-09-07T11:48:22Z"],["dc.date.issued","2012"],["dc.description.abstract","In plants, oxylipins regulate developmental processes and defense responses. The first specific step in the biosynthesis of the cyclopentanone class of oxylipins is catalyzed by allene oxide cyclase (AOC) that forms cis(+)-12-oxo-phytodienoic acid. The moss Physcomitrella patens has two AOCs (PpAOC1 and PpAOC2) with different substrate specificities for C-18- and C-20-derived substrates, respectively. To better understand AOC's catalytic mechanism and to elucidate the structural properties that explain the differences in substrate specificity, we solved and analyzed the crystal structures of 36 monomers of both apo and ligand complexes of PpAOC1 and PpAOC2. From these data, we propose the following intermediates in AOC catalysis: (1) a resting state of the apo enzyme with a closed conformation, (2) a first shallow binding mode, followed by (3) a tight binding of the substrate accompanied by conformational changes in the binding pocket, and (4) initiation of the catalytic cycle by opening of the epoxide ring. As expected, the substrate dihydro analog cis-12,13S-epoxy-9Z,15Z-octadecadienoic acid did not cyclize in the presence of PpAOC1; however, when bound to the enzyme, it underwent isomerization into the corresponding trans-epoxide. By comparing complex structures of the C-18 substrate analog with in silico modeling of the C-20 substrate analog bound to the enzyme allowed us to identify three major molecular determinants responsible for the different substrate specificities (i.e. larger active site diameter, an elongated cavity of PpAOC2, and two nonidentical residues at the entrance of the active site)."],["dc.identifier.doi","10.1104/pp.112.205138"],["dc.identifier.gro","3142446"],["dc.identifier.isi","000310584200009"],["dc.identifier.pmid","22987885"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8374"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0032-0889"],["dc.title","Crystal Structures of Physcomitrella patens AOC1 and AOC2: Insights into the Enzyme Mechanism and Differences in Substrate Specificity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","177"],["dc.bibliographiccitation.journal","BMC Plant Biology"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Meyer, Danilo"],["dc.contributor.author","Herrfurth, Cornelia"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T09:17:38Z"],["dc.date.available","2018-11-07T09:17:38Z"],["dc.date.issued","2013"],["dc.description.abstract","Background: Oilseed germination is characterized by the degradation of storage lipids. It may proceed either via the direct action of a triacylglycerol lipase, or in certain plant species via a specific lipid body 13-lipoxygenase. For the involvement of a lipoxygenase previous results suggested that the hydroxy-or oxo-group that is being introduced into the fatty acid backbone by this lipoxygenase forms a barrier to continuous beta-oxidation. Results: This study shows however that a complete degradation of oxygenated fatty acids is possible by isolated cucumber and sunflower glyoxysomes. Interestingly, degradation is accompanied by the formation of saturated short chain acyl-CoAs with chain length between 4 and 12 carbon atoms lacking the hydroxy-or oxo-diene system of the oxygenated fatty acid substrate. The presence of these CoA esters suggests the involvement of a specific reduction of the diene system at a chain length of 12 carbon atoms including conversion of the hydroxy-group at C7. Conclusions: To our knowledge this metabolic pathway has not been described for the degradation of polyunsaturated fatty acids so far. It may represent a new principle to degrade oxygenated fatty acid derivatives formed by lipoxygenases or chemical oxidation initiated by reactive oxygen species."],["dc.description.sponsorship","Deutsche Forschungs Gemeinschaft [FE 446/4]"],["dc.identifier.doi","10.1186/1471-2229-13-177"],["dc.identifier.isi","000329069200001"],["dc.identifier.pmid","24207097"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10049"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28212"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1471-2229"],["dc.rights","CC BY 2.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.0"],["dc.title","Degradation of lipoxygenase-derived oxylipins by glyoxysomes from sunflower and cucumber cotyledons"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","228"],["dc.bibliographiccitation.journal","BMC Plant Biology"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Scholz, Julia"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Hornung, Ellen"],["dc.contributor.author","Herrfurth, Cornelia"],["dc.contributor.author","Stumpe, Michael"],["dc.contributor.author","Beike, Anna K."],["dc.contributor.author","Faltin, Bernd"],["dc.contributor.author","Frank, Wolfgang"],["dc.contributor.author","Reski, Ralf"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T09:03:11Z"],["dc.date.available","2018-11-07T09:03:11Z"],["dc.date.issued","2012"],["dc.description.abstract","Background: The moss Physcomitrella patens contains C-18- as well as C-20-polyunsaturated fatty acids that can be metabolized by different enzymes to form oxylipins such as the cyclopentenone cis(+)-12-oxo phytodienoic acid. Mutants defective in the biosynthesis of cyclopentenones showed reduced fertility, aberrant sporophyte morphology and interrupted sporogenesis. The initial step in this biosynthetic route is the conversion of a fatty acid hydroperoxide to an allene oxide. This reaction is catalyzed by allene oxide synthase (AOS) belonging as hydroperoxide lyase (HPL) to the cytochrome P450 family Cyp74. In this study we characterized two AOS from P. patens, PpAOS1 and PpAOS2. Results: Our results show that PpAOS1 is highly active with both C-18 and C-20-hydroperoxy-fatty acid substrates, whereas PpAOS2 is fully active only with C-20-substrates, exhibiting trace activity (similar to 1000-fold lower k(cat)/K-M) with C-18 substrates. Analysis of products of PpAOS1 and PpHPL further demonstrated that both enzymes have an inherent side activity mirroring the close inter-connection of AOS and HPL catalysis. By employing site directed mutagenesis we provide evidence that single amino acid residues in the active site are also determining the catalytic activity of a 9-/13-AOS - a finding that previously has only been reported for substrate specific 13-AOS. However, PpHPL cannot be converted into an AOS by exchanging the same determinant. Localization studies using YFP-labeled AOS showed that PpAOS2 is localized in the plastid while PpAOS1 may be found in the cytosol. Analysis of the wound-induced cis(+)-12-oxo phytodienoic acid accumulation in PpAOS1 and PpAOS2 single knock-out mutants showed that disruption of PpAOS1, in contrast to PpAOS2, results in a significantly decreased cis(+)-12-oxo phytodienoic acid formation. However, the knock-out mutants of neither PpAOS1 nor PpAOS2 showed reduced fertility, aberrant sporophyte morphology or interrupted sporogenesis. Conclusions: Our study highlights five findings regarding the oxylipin metabolism in P. patens: (i) Both AOS isoforms are capable of metabolizing C-18- and C-20-derived substrates with different specificities suggesting that both enzymes might have different functions. (ii) Site directed mutagenesis demonstrated that the catalytic trajectories of 9-/13-PpAOS1 and PpHPL are closely inter-connected and PpAOS1 can be inter-converted by a single amino acid exchange into a HPL. (iii) In contrast to PpAOS1, PpAOS2 is localized in the plastid where oxylipin metabolism takes place. (iv) PpAOS1 is essential for wound-induced accumulation of cis(+)-12-oxo phytodienoic acid while PpAOS2 appears not to be involved in the process. (v) Knock-out mutants of neither AOS showed a deviating morphological phenotype suggesting that there are overlapping functions with other Cyp74 enzymes."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2012"],["dc.identifier.doi","10.1186/1471-2229-12-228"],["dc.identifier.isi","000314283900001"],["dc.identifier.pmid","23194461"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/8508"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24851"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1471-2229"],["dc.rights","CC BY 2.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.0"],["dc.title","Biosynthesis of allene oxides in Physcomitrella patens"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","95"],["dc.bibliographiccitation.journal","Frontiers in Plant Science"],["dc.bibliographiccitation.lastpage","24"],["dc.bibliographiccitation.volume","2"],["dc.contributor.author","Ibrahim, Amina"],["dc.contributor.author","Schütz, Anna-Lena"],["dc.contributor.author","Galano, Jean-Marie"],["dc.contributor.author","Herrfurth, Cornelia"],["dc.contributor.author","Feussner, Kirstin"],["dc.contributor.author","Durand, Thierry"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2019-07-09T11:53:15Z"],["dc.date.available","2019-07-09T11:53:15Z"],["dc.date.issued","2011"],["dc.description.abstract","Galactolipids constitute the major lipid class in plants. In recent years oxygenated derivatives of galactolipids have been detected. They are discussed as signal molecules during leaf damage, since they accumulate in wounded leaves in high levels. Using different analytical methods such as nuclear magnetic resonance, infra-red spectroscopy, and high performance liquid chromatography/mass spectrometry (HPLC/MS) earlier reports focused on the analysis of either oxidized or non-oxidized species and needed high levels of analytes. Here, we report on the analysis of the galactolipid subfraction of the Arabidopsis leaf lipidome by an improved HPLC/MS2-based method that is fast, robust, and comparatively simple in its performance. Due to a combination of phase partitioning, solid phase fractionation, liquid chromatography, and MS2 experiments this method has high detection sensitivity and requires only low amounts of plant material. With this method 167 galactolipid species were detected in leaves of Arabidopsis thaliana. Out of these 79 being newly described species. From all species the head group and acyl side chains were identified via MS2 experiments. Moreover, the structural identification was supported by HPLC/time-of-flight (TOF)-MS and gas chromatography (GC)/MS analysis. The quantification of different galactolipid species that accumulated 30 min after a mechanical wounding in A. thaliana leaves showed that the oxidized acyl side chains in galactolipids are divided into 65% cyclopentenones, 27% methyl-branched ketols, 3.8% hydroperoxides/straight-chain ketols, 2.0% hydroxides, and 2.6% phytoprostanes. In comparison to the free cyclopentenone derivatives, the esterified forms occur in a 149-fold excess supporting the hypothesis that galactolipids might function as storage compounds for cyclopentenones. Additional analysis of the ratio of non-oxidized to oxidized galactolipid species in leaves of wounded plants was performed resulting in a ratio of 2.0 in case of monogalactosyl diacylglycerol (MGD), 8.1 in digalactosyl diacylglycerol (DGD), and 0.6 in the acylated MGD. This indicates that galactolipid oxidation is a major and rapid metabolic process that occurs class specific."],["dc.identifier.doi","10.3389/fpls.2011.00095"],["dc.identifier.fs","587782"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7190"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60379"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","Frontiers Research Foundation"],["dc.relation.eissn","1664-462X"],["dc.rights","CC BY-NC 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc/3.0"],["dc.subject.ddc","570"],["dc.title","The alphabet of galactolipids in Arabidopsis thaliana"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]