100018-30-2Relevant academic research and scientific papers
Characterisation of lipoxygenase isoforms from olive callus cultures
Williams, Mark,Harwood, John L.
, p. 2532 - 2538 (2008)
Two lipoxygenase isoforms from olive callus cultures were separated from each other. Acetone powders were made to stabilise activity and remove lipids. Separation was then achieved by salt precipitation and ion-exchange chromatography. Both isoforms had comparable activity with linoleic and α-linolenic acid substrates, a basic pH optimum and had molecular masses of around 95 kDa. The callus extracts preferentially formed the 13-hydroperoxy products, in keeping with the pattern of volatile derivatives found in olive tissues and oils derived therefrom.
Detection of divinyl ether synthase in Lily-of-the-Valley (Convallaria majalis) roots
Ogorodnikova, Anna V.,Latypova, Larisa R.,Mukhitova, Fahima K.,Mukhtarova, Lucia S.,Grechkin, Alexander N.
, p. 2793 - 2798 (2008)
Incubations of linoleic acid with cell-free preparations from Lily-of-the-Valley (Convallaria majalis L., Ruscaceae) roots revealed the presence of 13-lipoxygenase and divinyl ether synthase (DES) activities. Exogenous linoleic acid was metabolized predominantly into (9Z,11E,1′E)-12-(1′-hexenyloxy)-9,11-dodecadienoic (etheroleic) acid. Its identification was confirmed by the data of ultraviolet spectroscopy, mass spectra, 1H NMR, COSY, catalytic hydrogenation. The isomeric divinyl ether (8E,1′E,3′Z)-12-(1′,3′-nonadienyloxy)-8-nonenoic (colneleic) acid was detected as a minor product. Incubations with linoleic acid hydroperoxides revealed that 13-hydroperoxide was a preferential substrate, while the 9-hydroperoxide was utilized with lesser efficiency.
Replacement of two amino acids of 9R-dioxygenase-allene oxide synthase of Aspergillus niger inverts the chirality of the hydroperoxide and the allene oxide
Sooman, Linda,Wennman, Anneli,Hamberg, Mats,Hoffmann, Inga,Oliw, Ernst H.
, p. 108 - 118 (2016)
The genome of Aspergillus niger codes for a fusion protein (EHA25900), which can be aligned with ～50% sequence identity to 9S-dioxygenase (DOX)-allene oxide synthase (AOS) of Fusarium oxysporum, homologues of the Fusarium and Colletotrichum complexes and with over 62% sequence identity to homologues of Aspergilli, including (DOX)-9R-AOS of Aspergillus terreus. The aims were to characterize the enzymatic activities of EHA25900 and to identify crucial amino acids for the stereospecificity. Recombinant EHA25900 oxidized 18:2n-6 sequentially to 9R-hydroperoxy-10(E),12(Z)-octadecadienoic acid (9R-HPODE) and to a 9R(10)-allene oxide. 9S- and 9R-DOX-AOS catalyze abstraction of the pro-R hydrogen at C-11, but the direction of oxygen insertion differs. A comparison between twelve 9-DOX domains of 9S- and 9R-DOX-AOS revealed conserved amino acid differences, which could contribute to the chirality of products. The Gly616Ile replacement of 9R-DOX-AOS (A. niger) increased the biosynthesis of 9S-HPODE and the 9S(10)-allene oxide, whereas the Phe627Leu replacement led to biosynthesis of 9S-HPODE and the 9S(10)-allene oxide as main products. The double mutant (Gly616Ile, Phe627Leu) formed over 90% of the 9S stereoisomer of HPODE. 9S-HPODE was formed by antarafacial hydrogen abstraction and oxygen insertion, i.e., the original H-abstraction was retained but the product chirality was altered. We conclude that 9R-DOX-AOS can be altered to 9S-DOX-AOS by replacement of two amino acids (Gly616Ile, Phe627Leu) in the DOX domain.
Whole-cell one-pot biosynthesis of azelaic acid
Otte, Konrad B.,Kittelberger, Jens,Kirtz, Marko,Nestl, Bettina M.,Hauer, Bernhard
, p. 1003 - 1009 (2014)
Polymers benefit from the use of biogenic resources such as fatty acids. They enable easy access to valuable monomeric building blocks, which, in comparison to their exclusively fossil counterparts, lead to products with improved physicochemical properties. Monomers of special interest are medium-chain dicarboxylic acids, which are not easy to obtain by traditional chemical means. Previously, we established an in vitro pathway that combined a 9-lipoxygenase and a 9/13-hydroperoxide lyase, which enabled the conversion of linoleic acid via a hydroperoxy intermediate into 9-oxononanoic acid, the precursor of azelaic acid. Herein, we aimed for the further development of the multi-enzyme cascade, which included the oxidation of 9-oxononanoic acid and the establishment of a suitable whole-cell catalyst. A detailed investigation of the simultaneous in vitro reaction setup revealed that both lipoxygenase activation and the subsequent hydroperoxide lyase reaction depend on the hydroperoxide reaction intermediate. For the activation of lipoxygenase, the hydroperoxide lyase activity, therefore, has to be significantly reduced. In accordance with these observations, we established a suitable dual-expression system and we further demonstrated that endogenous E. coli redox enzymes are feasible to oxidize 9-oxononanoic acid to azelaic acid. The resulting whole-cell catalyst is, therefore, able to perform the direct bioconversion of linoleic acid into azelaic acid. The use of organic solvent as the second phase improved the overall performance of the E. coli host strain. The developed one-pot, single-step process afforded 29 mg L-1 of azelaic acid within 8 h with a substrate conversion of 34 % and a selectivity of 47 %. Tiny polymer factories: An E. coli whole-cell catalyst is developed for the bioconversion of linoleic acid to azelaic acid, an important building block for biopolymers. The catalytic machinery of the prokaryotic host is equipped with two plant enzymes, a lipoxygenase, and a hydroperoxide lyase. Together with an endogenous oxidoreductase, this three-enzyme cascade reaction catalyzes the oxidative cleavage of the fatty acid substrate.
Identification and functional analyses of two cDNAs that encode fatty acid 9-/13-hydroperoxide lyase (CYP74C) in rice
Kuroda, Hisao,Oshima, Toshiyuki,Kaneda, Hirotaka,Takashio, Masachika
, p. 1545 - 1554 (2005)
Fatty acid hydroperoxide lyase (HPL), a member of cytochrome P450 (CYP74), produces aldehydes and oxoacids involved in plant defensive reactions. In monocots, HPL that cleaves 13-hydroperoxides of fatty acids has been reported, but HPL that cleaves 9-hydroperoxides is still unknown. To find this type of HPL, in silico screening of candidate cDNA clones and subsequent functional analyses of recombinant proteins were performed. We found that AK105964 and AK107161 (Genbank accession numbers), cDNAs previously annotated as allene oxide synthase (AOS) in rice, are distinctively grouped from AOS and 13-HPL. Recombinant proteins of these cDNAs produced in Escherichia. coli cleaved both 9- and 13-hydroperoxide of linoleic and linolenic into aldehydes, while having only a trace level of AOS activity and no divinyl ether synthase activity. Hence we designated AK105964 and AK107161 OsHPL1 and OsHPL2 respectively. They are the first CYP74C family cDNAs to be found in monocots.
Calcium modulates membrane association, positional specificity, and product distribution in dual positional specific maize lipoxygenase-1
Cho, Kyoungwon,Han, Jihoon,Rakwal, Randeep,Han, Oksoo
, p. 13 - 18 (2015)
This study investigates how calcium modulates the properties of dual positional specific maize lipoxygenase-1, including its interaction with substrate, association with subcellular membrane and alteration of product distribution. Bioinformatic analyses identified Asp38, Glu127 and Glu201 as putative calcium binding residues and Leu37 as a flanking hydrophobic residue also potentially involved in calcium-mediated binding of the enzyme to subcellular membranes. Asp38 and Leu37 were shown to be important but not essential for calcium-mediated association of maize lipoxygenase-1 to subcellular membranes in vitro. Kinetic studies demonstrate that catalytic efficiency (Vmax/Km) shows a bell-shaped dependence on log of the molar ratio of substrate to unbound calcium. Calcium also modulates product distribution of the maize lipoxygenase-1 reaction, favoring 13-positional specificity and increasing the relative amount of (E,Z)-isomeric products. The results suggest that calcium regulates the maize lipoxygenase-1 reaction by binding to substrate, and by promoting binding of substrate to enzyme and association of maize lipoxygenase-1 to subcellular membranes.
9-Hydroxy-10,12-octadecadienoic acid (9-HODE) and 13-hydroxy-9,11-octadecadienoic acid (13-HODE): Excellent markers for lipid peroxidation
Spiteller, Peter,Spiteller, Gerhard
, p. 131 - 139 (1997)
Various conditions for conversion of (9S,10E,12Z)-9-hydroperoxy-10,12-octadecadienoic acid (9S-HPODE) and (13S,9Z,10E)-13-hydroperoxy-9,11-octadecadienoic acid (13S-HPODE) into the corresponding hydroxy acids, (9S,10E,12Z)-9-hydroxy-10,12-octadecadienoic acid (9S-HODE) and (13S,9Z,10E)-13-hydroxy-9,11-octadecadienoic acid (13S-HODE), were investigated in vitro. 9S-HODE and 13S-HODE were subjected to lipid peroxidation under various conditions: oxidation was carried out in air only, and in air/Fe2+/ascorbate, air/H2O2/Fe2+, air/Fe2+, and air/Fe3+. In contrast to the corresponding hydroperoxides (9S-HPODE and 13S-HPODE), 9-HODE and 13-HODE proved to be stable in all these oxidation experiments. Unexpectedly, hydroxy compounds obtained by reduction of hydroperoxides derived from arachidonic acid were not attacked by air/Fe2+/ascorbate or air/Fe2+. Thus, for instance, (15S,5Z,8Z,11Z,13E)-15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) remained unchanged in spite of possessing the structural prerequisites for attack by radicals, i.e. a CH2-group located between two double bonds. Consequently, metal-induced air oxidation reactions of these systems seem to be restricted to hydroperoxides of unsaturated acids (LOOH) and not to corresponding hydroxy compounds (LOH). The reported experiments explain why hydroxy derivatives of unsaturated acids, especially 9-HODE and 13-HODE, are enriched in naturally occurring lipid peroxidation (LPO) processes to a greater extent than any other LPO product and why they are nearly ideal markers for LPO.
Characterization of 9-fatty acid hydroperoxide lyase-like activity in germinating barley seeds that transforms 9(S)-hydroperoxy-10(E),12(Z)- octadecadienoic acid into 2(E)-nonenal
Kuroda, Hisao,Kojima, Hidetoshi,Kaneda, Hirotaka,Takashio, Masachika
, p. 1661 - 1668 (2005)
Previously, we reported that 2(E)-nonenal, having a low flavor threshold (0.1 ppb) and known as the major contributor to a cardboard flavor (stale flavor) in stored beer, is produced by lipoxygenase-1 and a newly found factor named 9-fatty acid hydroperoxide lyase-like (9-HPL-like) activity in malt. To assess the involvement of 9-HPL-like activity in beer staling, we compared the values of the wort nonenal potential, an index for predicting the staleness of beer, with the lipoxygenase and 9-HPL-like activity of 20 commercial malts. There was a significant correlation between the malt 9-HPL-like activity and the values of wort nonenal potential (r = 0.53, P 0.05), while the correlation between malt lipoxygenase activity and the wort nonenal potential was statistically insignificant. Analysis of the partially purified 9-HPL-like activity from embryos of germinating barley seeds indicated that 9-HPL-like activity consisted of fatty acid hydroperoxide lyase and 3Z:2E isomerase.
Properties of a mini 9R-lipoxygenase from Nostoc sp. PCC 7120 and its mutant forms
Andreou, Alexandra-Zoi,Vanko, Marian,Bezakova, Lydia,Feussner, Ivo
, p. 1832 - 1837 (2008)
Lipoxygenases (LOXs) consist of a class of enzymes that catalyze the regio- and stereospecific dioxygenation of polyunsaturated fatty acids. Current reports propose that a conserved glycine residue in the active site of R-lipoxygenases and an alanine residue at the corresponding position in S-lipoxygenases play a crucial role in determining the stereochemistry of the product. Recently, a bifunctional lipoxygenase with a linoleate diol synthase activity from Nostoc sp. PCC7120 with R stereospecificity and the so far unique feature of carrying an alanine instead of the conserved glycine in the position of the sequence determinant for chiral specificity was identified. The recombinant carboxy-terminal domain was purified after expression in Escherichia coli. The ability of the enzyme to use linoleic acid esterified to a bulky phosphatidylcholine molecule as a substrate suggested a tail-fist binding orientation of the substrate. Site directed mutagenesis of the alanine to glycine did not cause alterations in the stereospecificity of the products, while mutation of the alanine to valine or isoleucine modified both regio- and enantioselectivity of the enzyme. Kinetic measurements revealed that substitution of Ala by Gly or Val did not significantly influence the reaction characteristics, while the A162I mutant showed a reduced vmax. Based on the mutagenesis data obtained, we suggest that the existing model for stereocontrol of the lipoxygenase reaction may be expanded to include enzymes that seem to have in general a smaller amino acid in R and a bulkier one in S lipoxygenases at the position that controls stereospecificity.
The CYP74B and CYP74D divinyl ether synthases possess a side hydroperoxide lyase and epoxyalcohol synthase activities that are enhanced by the site-directed mutagenesis
Gorina, Svetlana S.,Grechkin, Alexander N.,Iljina, Tatiana M.,Mukhtarova, Lucia S.,Smirnova, Elena O.,Toporkova, Yana Y.
, (2020/09/16)
The CYP74 family of cytochromes P450 includes four enzymes of fatty acid hydroperoxide metabolism: allene oxide synthase (AOS), hydroperoxide lyase (HPL), divinyl ether synthase (DES), and epoxyalcohol synthase (EAS). The present work is concerned with catalytic specificities of three recombinant DESs, namely, the 9-DES (LeDES, CYP74D1) of tomato (Solanum lycopersicum), 9-DES (NtDES, CYP74D3) of tobacco (Nicotiana tabacum), and 13-DES (LuDES, CYP74B16) of flax (Linum usitatissimum), as well as their alterations upon the site-directed mutagenesis. Both LeDES and NtDES converted 9-hydroperoxides of linoleic and α?linolenic acids to divinyl ethers colneleic and colnelenic acids (respectively) with only minorities of HPL and EAS products. In contrast, LeDES and NtDES showed low efficiency towards the linoleate 13-hydroperoxide, affording only the low yield of epoxyalcohols. LuDES exhibited mainly the DES activity towards α?linolenate 13-hydroperoxide (preferred substrate), and HPL activity towards linoleate 13-hydroperoxide, respectively. In contrast, LuDES converted 9-hydroperoxides primarily to the epoxyalcohols. The F291V and A287G mutations within the I-helix groove region (SRS-4) of LuDES resulted in the loss of DES activity and the acquirement of the epoxyalcohol synthase activity. Thus, the studied enzymes exhibited the versatility of catalysis and its qualitative alterations upon the site-directed mutagenesis.
