Sevanian A, Stein R A, Mead J F
Lipids. 1981 Nov;16(11):781-9. doi: 10.1007/BF02535029.
The isolation and measurement of phospholipid epoxides as major peroxidation products in biomembrane preparations prompted an investigation of enzymatic mechanisms which may be responsible for their elimination. Analysis of microsomal epoxide hydrolase and phospholipase A2 activity against a phospholipid epoxide commonly encountered in tissues indicated it to be a poor substrate for epoxide hydrolase, but rapidly hydrolyzed by phospholipase A2. Microsomal and purified phospholipase A2 preparations hydrolyzed the phospholipid epoxide at rates 2-fold greater than were observed with a monoenoic phospholipid from which the epoxide would be derived. The product fatty acid epoxide, cis-9,10-epoxystearic acid, was rapidly hydrated by microsomal and cytosolic epoxide hydrolase. On the basis of earlier reports demonstrating increased phospholipase activity against oxidized phospholipids, and on the results of the present study, a model for the metabolism of oxidized membrane phospholipids is proposed.
生物膜制剂中作为主要过氧化产物的磷脂环氧化物的分离和测量促使人们对可能负责其消除的酶促机制进行研究。针对组织中常见的一种磷脂环氧化物对微粒体环氧化物水解酶和磷脂酶A2活性的分析表明，它是环氧化物水解酶的不良底物，但能被磷脂酶A2迅速水解。微粒体和纯化的磷脂酶A2制剂水解磷脂环氧化物的速率比由其衍生出环氧化物的单烯磷脂的水解速率高2倍。产物脂肪酸环氧化物，即顺式-9,10-环氧硬脂酸，能被微粒体和胞质环氧化物水解酶迅速水化。基于早期报道显示针对氧化磷脂的磷脂酶活性增加以及本研究结果，提出了氧化膜磷脂代谢的模型。
