Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S]
The mycelium of the rice stem pathogen, Magnaporthe salvinii, secreted linoleate 9S-lipoxygenase (9S-LOX) and epoxy alcohol synthase (EAS). The EAS rapidly transformed 9S-hydroperoxy-octadeca-10E,12Z-dienoic acid (9S-HPODE) to threo 10 (11)-epoxy-9S-hydroxy-12Z-octadecenoic acid, but other hydropero...
Main Authors: | , |
---|---|
Format: | Article |
Language: | English |
Published: |
Elsevier
2013-03-01
|
Series: | Journal of Lipid Research |
Subjects: | |
Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520419406 |
id |
doaj-1641afe317a14fac92a5027313073714 |
---|---|
record_format |
Article |
spelling |
doaj-1641afe317a14fac92a50273130737142021-04-28T06:05:38ZengElsevierJournal of Lipid Research0022-22752013-03-01543762775Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S]Anneli Wennman0Ernst H. Oliw1Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, SwedenTo whom correspondence should be addressed. e-mail: Ernst.Oliw@farmbio.uu.se.; To whom correspondence should be addressed. e-mail: Ernst.Oliw@farmbio.uu.se.; Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Center, SE-751 24 Uppsala, SwedenThe mycelium of the rice stem pathogen, Magnaporthe salvinii, secreted linoleate 9S-lipoxygenase (9S-LOX) and epoxy alcohol synthase (EAS). The EAS rapidly transformed 9S-hydroperoxy-octadeca-10E,12Z-dienoic acid (9S-HPODE) to threo 10 (11)-epoxy-9S-hydroxy-12Z-octadecenoic acid, but other hydroperoxy FAs were poor substrates. 9S-LOX was expressed in Pichia pastoris. Recombinant 9S-LOX oxidized 18:2n-6 directly to 9S-HPODE, the end product, and also to two intermediates, 11S-hydroperoxy-9Z,12Z-octadecenoic acid (11S-HPODE; ∼5%) and 13R-hydroperoxy-9Z,11E-octadecadienoic acid (13R-HPODE; ∼1%). 11S- and 13R-HPODE were isomerized to 9S-HPODE, probably after oxidation to peroxyl radicals, β-fragmentation, and oxygen insertion at C-9. The 18:3n-3 was oxidized at C-9, C-11, and C-13, and to 9,16-dihydroxy-10E,12,14E-octadecatrienoic acid. 9S-LOX contained catalytic manganese (Mn:protein ∼0.2:1; Mn/Fe, 1:0.05), and its sequence could be aligned with 77% identity to 13R-LOX with catalytic manganese lipoxygenase (13R-MnLOX) of the Take-all fungus. The Leu350Met mutant of 9S-LOX shifted oxidation of 18:2n-6 from C-9 to C-13, and the Phe347Leu, Phe347Val, and Phe347Ala mutants of 13R-MnLOX from C-13 to C-9. In conclusion, M. salvinii secretes 9S-LOX with catalytic manganese along with a specific EAS. Alterations in the Sloane determinant of 9S-LOX and 13R-MnLOX with larger and smaller hydrophobic residues interconverted the regiospecific oxidation of 18:2n-6, presumably by altering the substrate position in relation to oxygen insertion.http://www.sciencedirect.com/science/article/pii/S0022227520419406lipoxygenase pathwaymetalloenzymemutagenesis site specifichydroperoxide rearrangementoxylipin biosynthesisregiospecificity |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Anneli Wennman Ernst H. Oliw |
spellingShingle |
Anneli Wennman Ernst H. Oliw Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] Journal of Lipid Research lipoxygenase pathway metalloenzyme mutagenesis site specific hydroperoxide rearrangement oxylipin biosynthesis regiospecificity |
author_facet |
Anneli Wennman Ernst H. Oliw |
author_sort |
Anneli Wennman |
title |
Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] |
title_short |
Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] |
title_full |
Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] |
title_fullStr |
Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] |
title_full_unstemmed |
Secretion of two novel enzymes, manganese 9S-lipoxygenase and epoxy alcohol synthase, by the rice pathogen Magnaporthe salvinii[S] |
title_sort |
secretion of two novel enzymes, manganese 9s-lipoxygenase and epoxy alcohol synthase, by the rice pathogen magnaporthe salvinii[s] |
publisher |
Elsevier |
series |
Journal of Lipid Research |
issn |
0022-2275 |
publishDate |
2013-03-01 |
description |
The mycelium of the rice stem pathogen, Magnaporthe salvinii, secreted linoleate 9S-lipoxygenase (9S-LOX) and epoxy alcohol synthase (EAS). The EAS rapidly transformed 9S-hydroperoxy-octadeca-10E,12Z-dienoic acid (9S-HPODE) to threo 10 (11)-epoxy-9S-hydroxy-12Z-octadecenoic acid, but other hydroperoxy FAs were poor substrates. 9S-LOX was expressed in Pichia pastoris. Recombinant 9S-LOX oxidized 18:2n-6 directly to 9S-HPODE, the end product, and also to two intermediates, 11S-hydroperoxy-9Z,12Z-octadecenoic acid (11S-HPODE; ∼5%) and 13R-hydroperoxy-9Z,11E-octadecadienoic acid (13R-HPODE; ∼1%). 11S- and 13R-HPODE were isomerized to 9S-HPODE, probably after oxidation to peroxyl radicals, β-fragmentation, and oxygen insertion at C-9. The 18:3n-3 was oxidized at C-9, C-11, and C-13, and to 9,16-dihydroxy-10E,12,14E-octadecatrienoic acid. 9S-LOX contained catalytic manganese (Mn:protein ∼0.2:1; Mn/Fe, 1:0.05), and its sequence could be aligned with 77% identity to 13R-LOX with catalytic manganese lipoxygenase (13R-MnLOX) of the Take-all fungus. The Leu350Met mutant of 9S-LOX shifted oxidation of 18:2n-6 from C-9 to C-13, and the Phe347Leu, Phe347Val, and Phe347Ala mutants of 13R-MnLOX from C-13 to C-9. In conclusion, M. salvinii secretes 9S-LOX with catalytic manganese along with a specific EAS. Alterations in the Sloane determinant of 9S-LOX and 13R-MnLOX with larger and smaller hydrophobic residues interconverted the regiospecific oxidation of 18:2n-6, presumably by altering the substrate position in relation to oxygen insertion. |
topic |
lipoxygenase pathway metalloenzyme mutagenesis site specific hydroperoxide rearrangement oxylipin biosynthesis regiospecificity |
url |
http://www.sciencedirect.com/science/article/pii/S0022227520419406 |
work_keys_str_mv |
AT anneliwennman secretionoftwonovelenzymesmanganese9slipoxygenaseandepoxyalcoholsynthasebythericepathogenmagnaporthesalviniis AT ernstholiw secretionoftwonovelenzymesmanganese9slipoxygenaseandepoxyalcoholsynthasebythericepathogenmagnaporthesalviniis |
_version_ |
1721504189953081344 |