Curtis M T, Gilfor D, Farber J L
Arch Biochem Biophys. 1984 Dec;235(2):644-9. doi: 10.1016/0003-9861(84)90239-x.
The effect of enzymatic lipid peroxidation on the molecular order of microsomal membranes was evaluated by ESR spectroscopy using the spin probes 5-, 12-, and 16-doxyl-stearic acid. Rat liver microsomal membranes were peroxidized by the NADPH-dependent reaction in the presence of the chelate ADP-Fe3+. Peroxidation resulted in a preferential depletion of polyenoic fatty acids and an increase in the percentage composition of shorter fatty acyl chains. There was no change in the cholesterol/phospholipid ratio of the peroxidized microsomes. The molecular order of both control and peroxidized membranes decreased toward the central region of the bilayer, and the order parameter (S) of each probe was temperature dependent. Peroxidation of the microsomal membrane lipids resulted in an increase in the order parameter determined with the three stearic acid spin probes. Of the three probes, 12-doxylstearic acid was the most sensitive to the changes in membrane organization caused by peroxidation. These data indicate that ESR spectroscopy is a sensitive method of detecting changes in membrane order accompanying peroxidation of membrane lipids.
利用自旋探针5-、12-和16-二氧硬脂酸，通过电子自旋共振光谱法评估了酶促脂质过氧化对微粒体膜分子有序性的影响。在螯合剂ADP-Fe3+存在的情况下，大鼠肝脏微粒体膜通过NADPH依赖性反应发生过氧化。过氧化导致多不饱和脂肪酸优先消耗，较短脂肪酰链的百分比组成增加。过氧化微粒体的胆固醇/磷脂比率没有变化。对照膜和过氧化膜的分子有序性均朝着双层的中心区域降低，并且每个探针的有序参数（S）都与温度有关。微粒体膜脂质的过氧化导致用三种硬脂酸自旋探针测定的有序参数增加。在这三种探针中，12-二氧硬脂酸对过氧化引起的膜组织变化最敏感。这些数据表明，电子自旋共振光谱法是检测膜脂质过氧化伴随的膜有序性变化的灵敏方法。
