EFFECT OF LIGHT ON LIPID PEROXIDATION IN CHLOROPLASTS
EFFECT OF LIGHT ON LIPID PEROXIDATION IN CHLOROPLASTS
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DOI：
10.1016/0006-291x(65)90316-5
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发表时间：
1965-01-01
影响因子：
3.1
通讯作者：
PACKER, L
中科院分区：
文献类型：
--
作者：
HEATH, RL;PACKER, L
在叶绿体退化的可能机制的调查，寻找证据的脂质过氧化反应，因为这种反应往往与膜损伤。叶绿体脂质中高浓度的不饱和脂肪酸，特别是亚麻酸（1）表明它们对快速循环过氧化反应的潜在敏感性。虽然已知叶绿素在化学系统中催化脂质过氧化（2），但叶绿体中发生这种反应尚未得到证实。在线粒体（3）和微粒体（4）中发现了脂质过氧化，Tappel和Zalkin描述了与变质和溶解相关的缓慢反应。在线粒体中，Schneider等人，(5)还表明，该过程与肿胀和膜破裂密切相关，并且在某些代谢条件下，线粒体的最终解体伴随脂质过氧化物产物的产生。在微粒体中，Hockstein等人最近描述了与NADPH氧化酶系统中的电子传递相关的脂质酶促过氧化反应1。（6）.从菠菜叶片中分离出叶绿体，置于NaCl（175 μ l）Tris-HCl（50 μ l，pR 8）中，并在0 ℃下于黑暗中保存1小时。用叶绿体进行的实验是在管中进行的，管保持在25 ℃，在光照（1800烛光）或黑暗中持续指定的时间间隔。然后进行测定以测试丙二醛的存在，丙二醛是多不饱和脂肪酸氢过氧化物（7，8）通过2-硫代巴比妥酸（TBA）反应的分解产物。该程序包括向等体积的样品中加入2.0 ml 0.5% TBA（溶于20$三氯乙酸中）。将该混合物在95 ℃下孵育25分钟，迅速冷却至室温。和吸收性
During an investigation of possible mechanisms involved in chloroplast deterioration, evidence was sought for lipid peroxidation since this reaction is frequently associated with membrane damage. The high concentrations of unsaturated fatty acids, particularly linolenic acid, in chloroplast lipids (1) suggests their potential susceptibility to rapid cyclic peroxidation reactions. Although chlorophyll is known in chemical systems to catalyze lipid peroxidation (2), the occurrence of this reaction in chloroplasts has not been demonstrated. Lipid peroxidation has been found in mitochondria (3) and microsomes (4) where a slow reaction associated with deterioration and lysis has been described by Tappel and Zalkin. In mitochondria, Schneider, et al.,(5) have also shown that the process is closely associated with swelling and membrane disruption, and eventual disintegration of mitochondria accompany production of lipid peroxide products under certain metabolic conditions. In microsomes an enzymatic peroxidation of lipids linked to electron transport in the NADPH oxidase system has recently been described by Hockstein et a1.(6).-- It now appears that a similar situation may exist in chloroplasts since the formation of malonaldehyde, a lipid peroxidation decomposition product, is remarkably-increased upon illumination of spinach chloroplasts.Chloroplasts were isolated from spinach leaves in NaCl (175 t&I) Tris-HCl (50 r&i, pR 8) and stored for periods up to one hour at 0'C in the dark. The experiments with chloroplasts were performed in tubes kept at 25'C either in the light (1800 f&candles) or dark for specified time intervals. Assays were then performed to test for the occurrence of malonaldehyde, a decomposition product of polyunsaturated fatty acid hydroperoxides (7, 8) by the 2-tniobarbituric acid (TBA) reaction. The procedure involved addition of 2.0 ml of 0.5% TBA (in 20$ trichloroacetic acid) to an equal volume of sample. This mixture was incubated for 25 minutes at 95'C, rapidly cooled to room temperature,. and absorbancy