28396-96-5Relevant academic research and scientific papers
Oxygenation reactions catalyzed by the F557V mutant of soybean lipoxygenase-1: Evidence for two orientations of substrate binding
Hershelman, Dillon,Kahler, Kirsten M.,Price, Morgan J.,Lu, Iris,Fu,Plumeri, Patricia A.,Karaisz, Fred,Bassett, Natasha F.,Findeis, Peter M.,Clapp, Charles H.
, (2019)
Plant lipoxygenases oxygenate linoleic acid to produce 13(S)-hydroperoxy-9Z,11E-octadecadienoic acid (13(S)-HPOD) or 9-hydroperoxy-10E,12Z-octadecadienoic acid (9(S)-HPOD). The manner in which these enzymes bind substrates and the mechanisms by which they control regiospecificity are uncertain. Hornung et al. (Proc. Natl. Acad. Sci. USA 96 (1999) 4192–4197) have identified an important residue, corresponding to phe-557 in soybean lipoxygenase-1 (SBLO-1). These authors proposed that large residues in this position favored binding of linoleate with the carboxylate group near the surface of the enzyme (tail-first binding), resulting in formation of 13(S)-HPOD. They also proposed that smaller residues in this position facilitate binding of linoleate in a head-first manner with its carboxylate group interacting with a conserved arginine residue (arg-707 in SBLO-1), which leads to 9(S)-HPOD. In the present work, we have tested these proposals on SBLO-1. The F557V mutant produced 33% 9-HPOD (S:R = 87:13) from linoleic acid at pH 7.5, compared with 8% for the wild-type enzyme and 12% with the F557V,R707L double mutant. Experiments with 11(S)-deuteriolinoleic acid indicated that the 9(S)-HPOD produced by the F557V mutant involves removal of hydrogen from the pro-R position on C-11 of linoleic acid, as expected if 9(S)-HPOD results from binding in an orientation that is inverted relative to that leading to 13(S)-HPOD. The product distributions obtained by oxygenation of 10Z,13Z-nonadecadienoic acid and arachidonic acid by the F557V mutant support the hypothesis that ω6 oxygenation results from tail-first binding and ω10 oxygenation from head-first binding. The results demonstrate that the regiospecificity of SBLO-1 can be altered by a mutation that facilitates an alternative mode of substrate binding and adds to the body of evidence that 13(S)-HPOD arises from tail-first binding.
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.
Epoxyalcohol Synthase RjEAS (CYP74A88) from the Japanese Buttercup (Ranunculus japonicus): Cloning and Characterization of Catalytic Properties
Toporkova,Fatykhova,Gorina,Mukhtarova,Grechkin
, p. 171 - 180 (2019/04/01)
Cytochromes P450 of the CYP74 family play a key role in the lipoxygenase cascade generating oxylipins (products of polyunsaturated fatty acid oxidation). The CYP74 family includes allene oxide synthases, hydroperoxide lyases, divinyl ether synthases, and epoxyalcohol synthases. In this work, we cloned the CYP74A88 gene from the Japanese buttercup (Ranunculus japonicus) and studied the properties of the encoded recombinant protein. The CYP74A88 enzyme specifically converts linoleic acid 9-and 13-hydroperoxides to oxiranyl carbinols 9,10-epoxy-11-hydroxy-12-octadecenoic acid and 11-hydroxy-12,13-epoxy-9-octadecenoic acid, respectively, which was confirmed by GC-MS analysis and kinetic studies. Therefore, the CYP74A88 enzyme is a specific epoxyalcohol synthase.
Allene Oxide Synthase Pathway in Cereal Roots: Detection of Novel Oxylipin Graminoxins
Grechkin, Alexander N.,Ogorodnikova, Anna V.,Egorova, Alevtina M.,Mukhitova, Fakhima K.,Ilyina, Tatiana M.,Khairutdinov, Bulat I.
, p. 336 - 343 (2018/06/04)
Young roots of wheat, barley, and sorghum, as well as methyl jasmonate pretreated rice seedlings, undergo an unprecedented allene oxide synthase pathway targeted to previously unknown oxylipins 1–3. These Favorskii-type products, (4Z)-2-pentyl-4-tridecene-1,13-dioic acid (1), (2′Z)-2-(2′-octenyl)-decane-1,10-dioic acid (2), and (2′Z,5′Z)-2-(2′,5′-octadienyl)-decane-1,10-dioic acid (3), have a carboxy function at the side chain, as revealed by their MS and NMR spectral data. Compounds 1–3 were the major oxylipins detected, along with the related α-ketols. Products 1–3 were biosynthesized from (9Z,11E,13S)-13-hydroperoxy-9,11-octadecadienoic acid, (9S,10E,12Z)-9-hydroperoxy-10,12-octadecadienoic acid (9-HPOD), and (9S,10E,12Z,15Z)-9-hydroperoxy-10,12,15-octadecatrienoic acid, respectively, via the corresponding allene oxides and cyclopropanones. The data indicate that conversion of the allene oxide into the cyclopropanone is controlled by soluble cyclase. The short-lived cyclopropanones are hydrolyzed to products 1–3. The collective name “graminoxins” has been ascribed to oxylipins 1–3.
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 (2016/01/08)
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.
Liquid chromatography-tandem mass spectrometry determination of human plasma 1-palmitoyl-2-hydroperoxyoctadecadienoyl-phosphatidylcholine isomers via promotion of sodium adduct formation
Kato, Shunji,Nakagawa, Kiyotaka,Suzuki, Yuuri,Asai, Akira,Nagao, Mototsugu,Nagashima, Kazuyuki,Oikawa, Shinichi,Miyazawa, Teruo
, p. 51 - 60 (2015/03/04)
Accumulation of phosphatidylcholine hydroperoxide (PCOOH), a primary oxidation product of phosphatidylcholine, in blood plasma has been observed in various pathological conditions, including atherosclerosis. In this study, we investigated the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to develop a method for accurate quantification of PCOOH (1-palmitoyl-2-hydroperoxyoctadecadienoyl-sn-glycero-3-phosphocholine, 16:0/HpODE PC), focusing on isomers such as 16:0/13-HpODE PC and 16:0/9-HpODE PC. Sodiated PCOOH ([M+Na]+, m/z 812) provided not only a known product ion (m/z 147) but also characteristic product ions (m/z 541 for 16:0/13-HpODE PC and m/z 388 for 16:0/9-HpODE PC). Thus, three multiple reaction monitorings (MRMs) could be performed. MRM (812/147) enabled determination of 16:0/HpODE PC, and MRM (812/541) and MRM (812/388) allowed specific measurement of 16:0/13-HpODE PC and 16:0/9-HpODE PC, respectively. By using this method, we could determine plasma PCOOH concentrations in healthy subjects and patients with angiographically significant stenosis. In healthy subject and patient plasma, the concentration of 16:0/HpODE PC was close to the sum of the concentrations of 16:0/13-HpODE PC and 16:0/9-HpODE PC. This finding shows that radical and/or enzymatic oxidation, rather than singlet oxygen oxidation, is recognized to cause peroxidation of PC. The newly developed LC-MS/MS method appears to be a powerful tool for developing a better understanding of in vivo lipid peroxidation and its involvement in human diseases.
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 (2015/04/27)
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.
Whole-cell one-pot biosynthesis of azelaic acid
Otte, Konrad B.,Kittelberger, Jens,Kirtz, Marko,Nestl, Bettina M.,Hauer, Bernhard
, p. 1003 - 1009 (2014/05/06)
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 of an amino acid determinant of pH regiospecificity in a seed lipoxygenase from Momordica charantia
Hornung, Ellen,Kunze, Susan,Liavonchanka, Alena,Zimmermann, Grit,Kuehn, Diana,Fritsche, Kathrin,Renz, Andreas,Kuehn, Hartmut,Feussner, Ivo
scheme or table, p. 2774 - 2780 (2009/04/10)
Lipoxygenases (LOX) form a heterogeneous family of lipid peroxidizing enzymes, which catalyze specific dioxygenation of polyunsaturated fatty acids. According to their positional specificity of linoleic acid oxygenation plant LOX have been classified into linoleate 9- and linoleate 13-LOX and recent reports identified a critical valine at the active site of 9-LOX. In contrast, more bulky phenylalanine or histidine residues were found at this position in 13-LOX. We have recently cloned a LOX-isoform from Momordica charantia and multiple amino acid alignments indicated the existence of a glutamine (Gln599) at the position were 13-LOX usually carry histidine or phenylalanine residues. Analyzing the pH-dependence of the positional specificity of linoleic acid oxygenation we observed that at pH-values higher than 7.5 this enzyme constitutes a linoleate 13-LOX whereas at lower pH, 9-H(P)ODE was the major reaction product. Site-directed mutagenesis of glutamine 599 to histidine (Gln599His) converted the enzyme to a pure 13-LOX. These data confirm previous observation suggesting that reaction specificity of certain LOX-isoforms is not an absolute enzyme property but may be impacted by reaction conditions such as pH of the reaction mixture. We extended this concept by identifying glutamine 599 as sequence determinant for such pH-dependence of the reaction specificity. Although the biological relevance for this alteration switch remains to be investigated it is of particular interest that it occurs at near physiological conditions in the pH-range between 7 and 8.
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.
experimental part, p. 2793 - 2798 (2009/04/11)
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.
