SUPEROXIDE AND PEROXYL RADICAL GENERATION FROM THE REDUCTION OF POLYUNSATURATED FATTY-ACID HYDROPEROXIDES BY SOYBEAN LIPOXYGENASE
SUPEROXIDE AND PEROXYL RADICAL GENERATION FROM THE REDUCTION OF POLYUNSATURATED FATTY-ACID HYDROPEROXIDES BY SOYBEAN LIPOXYGENASE
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DOI：
10.1016/0003-9861(91)90601-e
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发表时间：
1991-10-01
影响因子：
3.9
通讯作者：
MASON, RP
中科院分区：
文献类型：
--
作者：
CHAMULITRAT, W;HUGHES, MF;MASON, RP
大豆脂肪氧合酶催化多不饱和脂肪酸过氧化氢分解产生超氧阴离子自由基，用5，5-二甲基-1-吡咯啉-N-氧化物（DMPO）自旋捕集法检测。除了DMPO/超氧自由基加合物，过氧，酰基，碳为中心的，和羟基自由基的加合物被确定在含有亚油酸和脂氧合酶的孵育。这些DMPO自由基加合物被观察到之前，系统成为厌氧。只有碳为中心的自由基加合物在厌氧条件下观察到。超氧自由基的产生需要脂肪酸底物、脂肪酸氢过氧化物、活性脂氧合酶和分子氧的存在。超氧自由基的产生被抑制时，nordihydroguaiaretic酸，丁基羟基甲苯，或丁基羟基茴香醚被添加到孵育混合物。我们建议，多不饱和脂肪酸氢过氧化物被减少，形成烷氧基自由基和分子内重排后，所产生的羟烷基自由基与氧反应，形成过氧自由基，随后消除超氧阴离子自由基。
Soybean lipoxygenase is shown to catalyze the breakdown of polyunsaturated fatty acid hydroperoxides to produce superoxide radical anion as detected by spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). In addition to the DMPO/superoxide radical adduct, the adducts of peroxyl, acyl, carbon-centered, and hydroxyl radicals were identified in incubations containing linoleic acid and lipoxygenase. These DMPO radical adducts were observed just prior to the system becoming anaerobic. Only a carbon-centered radical adduct was observed under anaerobic conditions. The superoxide radical production required the presence of fatty acid substrates, fatty acid hydroperoxides, active lipoxygenase, and molecular oxygen. Superoxide radical production was inhibited when nordihydroguaiaretic acid, butylated hydroxytoluene, or butylated hydroxyanisole was added to the incubation mixtures. We propose that polyunsaturated fatty acid hydroperoxides are reduced to form alkoxyl radicals and that after an intramolecular rearrangement, the resulting hydroxyalkyl radical reacts with oxygen, forming a peroxyl radical which subsequently eliminates superoxide radical anion.