Satoh K, Katoh S
Biochim Biophys Acta. 1979 Mar 15;545(3):454-65. doi: 10.1016/0005-2728(79)90154-3.
Light -induced absorbance changes at 560 nm in dark-adapted intact chloroplasts of the green alga, Bryopsis maxima were studied in the time range of 200 ms. The initial rise of the 560 nm signals consists of two major components which are both electrochromic absorbance changes of the carotenoids, siponein and/or siphonaxanthin, but different in mechanisms of the field formation. The first component (component S) is related to electron transport since it was sensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) and showed at light-intensity dependence similar to that of electron transport in chloroplasts. In the presence of DCMU, component S could be restored on addition of proton-transporting electron donors such as reduced 2.6-dichlorophenol indophenol and phenazine methosulfate, but not on addition of N,N,N',N'-tetramethyl-p-phenylenediamine which does not carry protons with electrons (Trebst, A. (1974) Annu. Rev. Plant Physiol. 25, 423--458). We propose that component S is due to the electric field set up by the proton translocation across the thylakoid membrane. The second component (component R) was resistant to DCMU and DBMIB. The light-intensity dependency of component R was similar to that of cytochrome f photooxidation which showed saturation at a relatively low light intensity. The magnitude of component R was markedly reduced by phenylmercuric acetate, suggesting the participation of ferredoxin and ferredoxin-NADP oxidoreductase in the mechanism of the field formation responsible for this component. In the presence of DCMU and phenylmercuric acetate, time courses of the 560 nm changes paralleled those of cytochrome f changes. These results indicate that component R is due to the electric field formed between oxidized cytochrome f and other intersystem electron carriers located in the inner part of the thylakoid membrane and reduced electron acceptors of Photosystem I situated on the membrane surface. The complex natures of the 560 nm changes, as well as the contributions of Photosystems I and II to the absorbance changes, are explained in terms of the two electrogenic mechanisms.
在200毫秒的时间范围内，研究了绿藻巨藻（Bryopsis maxima）暗适应完整叶绿体在560纳米处光诱导的吸光度变化。560纳米信号的初始上升由两个主要成分组成，这两个成分都是类胡萝卜素、西波宁和/或西波黄质的电致变色吸光度变化，但场形成机制不同。第一个成分（成分S）与电子传递有关，因为它对3-(3,4-二氯苯基)-1,1-二甲基脲（DCMU）和2,5-二溴-3-甲基-6-异丙基对苯醌（DBMIB）敏感，并且显示出与叶绿体中电子传递相似的光强依赖性。在DCMU存在的情况下，添加质子转运电子供体如还原型2,6-二氯酚靛酚和吩嗪硫酸甲酯时，成分S可以恢复，但添加不携带质子的电子供体N,N,N',N'-四甲基对苯二胺时则不能恢复（特莱布斯特，A.（1974年）《植物生理学年度评论》25，423 - 458）。我们提出成分S是由于质子跨类囊体膜转运建立的电场所致。第二个成分（成分R）对DCMU和DBMIB有抗性。成分R的光强依赖性与细胞色素f光氧化的相似，细胞色素f光氧化在相对较低的光强下显示饱和。醋酸苯汞显著降低了成分R的幅度，表明铁氧化还原蛋白和铁氧化还原蛋白 - NADP氧化还原酶参与了负责该成分的场形成机制。在DCMU和醋酸苯汞存在的情况下，560纳米变化的时间进程与细胞色素f变化的时间进程平行。这些结果表明成分R是由于氧化型细胞色素f与位于类囊体膜内部的其他系统间电子载体以及位于膜表面的光系统I的还原型电子受体之间形成的电场所致。560纳米变化的复杂性质以及光系统I和II对吸光度变化的贡献，根据这两种产电机制进行了解释。
