Effect of solution ionic strength on lipid peroxidation initiation by the perhydroxyl (xanthine oxidase-derived) and peroxyl radicals.
Effect of solution ionic strength on lipid peroxidation initiation by the perhydroxyl (xanthine oxidase-derived) and peroxyl radicals.
复制标题
溶液离子强度对过羟基（黄嘌呤氧化酶衍生的）和过氧自由基引发脂质过氧化的影响。
DOI：
10.1021/tx00026a018
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发表时间：
1992
影响因子：
4.1
通讯作者：
Dix,TA
中科院分区：
文献类型：
--
作者：
Aikens,J;Dix,TA
研究了溶液离子强度在过羟基（HOO*）和过氧化氢（ROO*）自由基引发的脂质过氧化反应中的作用。在这些实验中，黄嘌呤氧化酶活性用作超氧化物（O2-）及其共辄酸（HOO*）的来源。虽然酶的活性随着离子强度的变化而变化，但这种影响可以从脂质过氧化研究中排除。HOO*-和ROO '-引发的亚油酸过氧化反应都受到溶液离子强度增加的促进：在反应中加入0.1 M的各种碱金属盐导致总过氧化速率增加4倍。未观察到碱金属阳离子（Li+、Na+、K+、Cs+）和卤素阴离子（F-、Cl-、Br-）之间的显著差异。因此，脂质过氧化反应速率的增加可归因于溶液离子强度的变化，而不是特定的离子反应相互作用。脂质过氧化的离子刺激仅在预先存在的脂肪酸氢过氧化物（LOOH）的存在下发生，这为先前提出的氢原子转移机制提供了额外的支持[Aikens，J.，和Dix，T. A.（1991）J.Biol.Chem.266，15091]用于HOO*/LOOH引发过程。在这些研究中使用了生理上适当的盐浓度，因此结果可能具有生物学意义。
The role of solution ionic strength in perhydroxyl (HOO*) and peroxyl (ROO*) radical initiated lipid peroxidation has been defined and investigated. Xanthine oxidase activity was used as the source of superoxide (02 “) and its conjugate acid (HOO*) in these experiments. While the enzyme’s activity varied with changes in ionic strength, the effect could be factored out of the lipid peroxidation studies. Both HOO*-and ROO'-initiated peroxidations of linoleic acid were promoted by increases in solution ionic strength: the inclusion of 0.1 M of various alkali metal salts in the reaction resulted in up to a 4-fold increase in theoverall peroxidation rate. Significant differences between alkali metal cations (Li+, Na+, K+, Cs+) and halogen anions (F", Cl", Br") were not observed. Thus, the increased rates of lipid peroxidation were attributable to changes in solution ionic strength rather than specific ion-reaction interactions. Ionicstimulation of lipid peroxidation occurred only in the presence of preexisting fatty acid hydroperoxides (LOOHs), which provided additional support for the hydrogen atom transfer mechanism previously proposed [Aikens, J., and Dix, T. A.(1991) J. Biol. Chem. 266, 15091] for the HOO*/LOOH initiation process. Physiologically appropriate salt concentrations were used in these studies, hence the results may have biological significance.