Biochemical characterization of polyunsaturated fatty acid synthesis in Schizochytrium : release of the products as free fatty acids

In marine bacteria and some thraustochytrids (marine stramenopiles) long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are produced de novo by PUFA synthases. These large, multi-domain enzymes carry out the multitude of individual rea...

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Veröffentlicht in:Plant physiology and biochemistry : PPB. - 1991. - 47(2009), 6 vom: 01. Juni, Seite 472-8
1. Verfasser: Metz, James G (VerfasserIn)
Weitere Verfasser: Kuner, Jerry, Rosenzweig, Bradley, Lippmeier, James C, Roessler, Paul, Zirkle, Ross
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2009
Zugriff auf das übergeordnete Werk:Plant physiology and biochemistry : PPB
Schlagworte:Journal Article Enzyme Inhibitors Fatty Acids, Nonesterified Fatty Acids, Unsaturated Plant Oils Triglycerides Docosahexaenoic Acids 25167-62-8 Malonyl Coenzyme A 524-14-1 mehr... Adenosine Triphosphate 8L70Q75FXE Thiolester Hydrolases EC 3.1.2.- Fatty Acid Synthase, Type II EC 6.- Acetate-CoA Ligase EC 6.2.1.1 Magnesium I38ZP9992A docosapentaenoic acid NS3OZT14QT
Beschreibung
Zusammenfassung:In marine bacteria and some thraustochytrids (marine stramenopiles) long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are produced de novo by PUFA synthases. These large, multi-domain enzymes carry out the multitude of individual reactions required for conversion of malonyl-CoA to the final LC-PUFA products. Here we report on the release of fatty acids from the PUFA synthase found in Schizochytrium, a thraustochytrid that has been developed as a commercial source for DHA-enriched biomass and oil. Data from in vitro activity assays indicate that the PUFAs are released from the enzyme as free fatty acids (FFAs). Addition of ATP and Mg(2+) to in vitro assays facilitates appearance of radiolabel from (14)C-malonyl-CoA in a triacylglycerol fraction, suggesting the involvement of acyl-CoA synthetases (ACS). Furthermore, addition of triascin C, an inhibitor of ACSs, to the assays blocks this conversion. When the Schizochytrium PUFA synthase is expressed in Escherichia coli, the products of the enzyme accumulate as FFAs, suggesting that the thioesterase activity required for fatty acid release is an integral part of the PUFA synthase
Beschreibung:Date Completed 21.10.2009
Date Revised 09.01.2024
published: Print-Electronic
Citation Status MEDLINE
ISSN:1873-2690
DOI:10.1016/j.plaphy.2009.02.002