73543-67-6Relevant articles and documents
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.
, (2019/09/10)
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.
Microbial Synthesis of Linoleate 9 S-Lipoxygenase Derived Plant C18 Oxylipins from C18 Polyunsaturated Fatty Acids
An, Jung-Ung,Lee, In-Gyu,Ko, Yoon-Joo,Oh, Deok-Kun
, p. 3209 - 3219 (2019/03/26)
Plant oxylipins, including hydroxy fatty acids, epoxy hydroxy fatty acids, and trihydroxy fatty acids, which are biosynthesized from C18 polyunsaturated fatty acids (PUFAs), are involved in pathogen-specific defense mechanisms against fungal infections. However, their quantitative biotransformation by plant enzymes has not been reported. A few bacteria produce C18 trihydroxy fatty acids, but the enzymes and pathways related to the biosynthesis of plant oxylipins in bacteria have not been reported. In this study, we first report the biotransformation of C18 PUFAs into plant C18 oxylipins by expressing linoleate 9S-lipoxygenase with and without epoxide hydrolase from the proteobacterium Myxococcus xanthus in recombinant Escherichia coli. Among the nine types of plant oxylipins, 12,13-epoxy-14-hydroxy-cis,cis-9,15-octadecadienoic acid was identified as a new compound by NMR analysis, and 9,10,11-hydroxy-cis,cis-6,12-octadecadienoic acid and 12,13,14-trihydroxy-cis,cis-9,15-octadecadienoic were suggested as new compounds by LC-MS/MS analysis. This study shows that bioactive plant oxylipins can be produced by microbial enzymes.
Stereospecific production of 9R-hydroxy-10E,12Z-octadecadienoic acid from linoleic acid by recombinant Escherichia coli cells expressing 9R-lipoxygenase from Nostoc sp. SAG 25.82
Kim, Kyoung-Rok,Seo, Min-Ho,Park, Jin-Byung,Oh, Deok-Kun
, p. 56 - 63 (2014/05/06)
One of the most significant properties of lipoxygenase (LOX) as a biocatalyst is its stereo-selective oxygenation. In this study, the stereo-specific production of 9R-hydroxy-10E,12Z-octadecadienoic acid (9R-HODE) from linoleic acid was achieved using whole recombinant Escherichia coli cells expressing LOX from Nostoc sp. SAG 25.82. The optimal conditions for the production of 9R-HODE were pH 7.5, 25 °C, 40 g l-1 cells, 15 g l-1 linoleic acid, 2% (v/v) methanol, 1 working volume/oxygen volume/min (vvm) oxygenation rate, and 250 rpm agitation speed in 500 ml-baffled flask containing a working volume of 50 ml. Under these optimized conditions, whole recombinant cells expressing 9R-LOX protein produced 14.3 g l-1 9R-HODE for 1 h, with a conversion yield of 95% (w/w) and a productivity of 14.3 g l-1 h-1. The oxygen supply method significantly influenced stereo- and regio-selectivity of the oxygenation of linoleic acid. Among the oxygen supply methods tested, oxygenation (1 vvm) with agitation (250 rpm) resulted in the highest 9R/13S-HODE ratio of the products at 96:4. This is the first application using whole recombinant cells harboring R-specific LOX for the stereo-selective production of an R-specific hydroxy fatty acid.
