Brown L R, Wüthrich K
Biochim Biophys Acta. 1977 Jan 21;464(2):356-69. doi: 10.1016/0005-2736(77)90010-4.
Rapid loss of the electron spin resonance signal from a variety of spin labels is observed when ferricytochrome c or metmyoglobin are combined with lipids. Evidence is presented that this loss of signal can be used as a sensitive method to study lipid oxidation catalyzed by heme proteins. Under aerobic conditions and with lipids which bind the heme protein, the kinetics of the oxidation process as observed by the spin label method are identical to the kinetics previously observed by measurements of oxygen uptake. Use of pre-oxidized lipids under anaerobic conditions indicates that cytochrome c reacts with a product of lipid oxidation. Kinetic studies of the anaerobic reaction indicate that cytochrome c reacts rapidly with lipid oxidation products in membrane areas far larger than the area occupied by cytochrome c, implying rapid transport of reactive species within the membrane interior in directions parallel to the membrane surface. Under anaerobic conditions, reaction of cytochrome c with lipid oxidation products appears to produce a relatively long lived (hours) species located in the hydrophobic portion of the membrane, which is capable of subsequent reaction with lipid-soluble spin labels.
当高铁细胞色素c或高铁肌红蛋白与脂质结合时，会观察到来自各种自旋标记物的电子自旋共振信号迅速丧失。有证据表明，这种信号丧失可作为研究血红素蛋白催化脂质氧化的一种灵敏方法。在有氧条件下，对于能结合血红素蛋白的脂质，通过自旋标记法观察到的氧化过程动力学与之前通过测量氧气摄取所观察到的动力学相同。在厌氧条件下使用预氧化脂质表明，细胞色素c与脂质氧化产物发生反应。对厌氧反应的动力学研究表明，细胞色素c在远大于细胞色素c所占面积的膜区域内与脂质氧化产物迅速反应，这意味着反应性物种在膜内部沿平行于膜表面的方向快速运输。在厌氧条件下，细胞色素c与脂质氧化产物的反应似乎产生了一种位于膜疏水部分的寿命相对较长（数小时）的物种，该物种能够随后与脂溶性自旋标记物发生反应。
