Sattler W, Maiorino M, Stocker R
Biochemistry Group, Heart Research Institute, Sydney, New South Wales, Australia.
Arch Biochem Biophys. 1994 Mar;309(2):214-21. doi: 10.1006/abbi.1994.1105.
The reaction of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and Ebselen with phospholipid and cholesterylester hydroperoxides associated with HDLox and LDLox was investigated using specific HPLC assays for the hydroperoxides of phosphatidylcholine (PCOOH) and cholesteryllinolate (Ch18:2-OOH) and for cholesteryllinolate hydroxides (Ch18:2-OH). HDLox and LDLox were formed from the corresponding isolated native lipoproteins by controlled and limited oxidation initiated by aqueous peroxyl radicals. Incubation of HDLox or LDLox in the presence of PHGPx/GSH or Ebselen/GSH resulted in rapid degradation of both classes of lipid hydroperoxides, with equimolar amounts of Ch18:2-OH formed from Ch18:2-OOH. No pronounced differences were observed between PCOOH and Ch18:2-OOH in terms of substrate specificity, whereas HDLox-associated PCOOH and Ch18:2-OOH appeared to be slightly better substrates for PHGPx/GSH as compared to those in LDLox. Also, Ch18:2-OOH associated with HDLox but not LDLox were reduced by Ebselen or GSH alone. These in vitro findings indicate that the enzymatic PHGPx/GSH and the nonenzymatic Ebselen/GSH systems can efficiently reduce hydroperoxides of phospholipids and cholesterylesters associated with intact lipoproteins.
使用针对磷脂酰胆碱（PCOOH）和亚油酸胆固醇酯（Ch18:2-OOH）的氢过氧化物以及亚油酸胆固醇酯氢氧化物（Ch18:2-OH）的特定HPLC分析方法，研究了磷脂氢过氧化物谷胱甘肽过氧化物酶（PHGPx）和依布硒仑与与氧化高密度脂蛋白（HDLox）和氧化低密度脂蛋白（LDLox）相关的磷脂和胆固醇酯氢过氧化物的反应。HDLox和LDLox由相应的分离天然脂蛋白通过水相过氧自由基引发的受控有限氧化形成。在PHGPx/GSH或依布硒仑/GSH存在下孵育HDLox或LDLox会导致两类脂质氢过氧化物迅速降解，由Ch18:2-OOH形成等摩尔量的Ch18:2-OH。在底物特异性方面，未观察到PCOOH和Ch18:2-OOH之间有明显差异，而与HDLox相关的PCOOH和Ch18:2-OOH与LDLox中的相比，似乎是PHGPx/GSH更好的底物。此外，与HDLox相关但与LDLox无关的Ch18:2-OOH可被依布硒仑或单独的GSH还原。这些体外研究结果表明，酶促PHGPx/GSH和非酶促依布硒仑/GSH系统可以有效还原与完整脂蛋白相关的磷脂和胆固醇酯的氢过氧化物。
