Lipid Peroxidation in Egg Phosphatidylcholine Liposomes: Comparative Studies on the Induction Systems Fe2+/Ascorbate and Fe3+-Chelates/Xanthine-Xanthine Oxidase.

DOI Web Site PubMed 被引用文献4件 参考文献19件

この論文をさがす

説明

Two typical systems of lipid peroxidation in egg yolk phosphatidylcholine (egg PC) liposomes were compared : an enzymic system involving superoxide (O-2) generated by xanthine (X), xanthine oxidase (XO) and Fe3+-chelates (Fe3+-ADP and Fe3+-EDTA), and a non-enzymic system involing ascorbic acid (AsA) and Fe2+. These two systems exhibited a different pH-dependence : the rate in the enzymic system was maximal at pH 8-8.5, wheareas that in the non-enzymic system was high below pH 7.4 and low above pH 7.6. The rates of lipid peroxidation differed with the membrane charge, and this charge-dependent phenomenon differed in the two peroxidation systems : in the Fe3+-chelates/X-XO-system, the rate was slow in neutrally charged egg PC liposomes and rapid in egg PC liposomes containing negatively charged dicetylphosphate (DCP) or positively charged stearylamine (SA), whereas in the Fe2+/AsA-system, the rate was rapid in neutral egg PC liposomes but no lipid peroxidation occurred in egg PC liposomes charged with DCP or SA. The decomposition rate of the hydroperoxide of PC (PC-OOH) incorporated into dimyristoyl-phosphatidylcholine (DMPC) liposomes differed depending on the membrane charge in the two systems and this charge-dependence of the rates correlated well with that of the initiation rate of lipid peroxidation dependent on membrane charge. In the Fe2+/AsA-system, lipid peroxidation depended on the endogenous presence of PC-OOH, and the amounts of PC-OOH required for initiation of the reaction differed depending on the membrane charge. However, in the Fe3+-chelates/X-XO-system, lipid peroxidation occurred very slowly in the absence of PC-OOH, but rapidly in its presence.

収録刊行物

被引用文献 (4)*注記

もっと見る

参考文献 (19)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ