Samuilov V D, Kiselevsky D B
Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia.
Biochemistry (Mosc). 2015 Apr;80(4):417-23. doi: 10.1134/S0006297915040045.
Plastoquinone bound with decyltriphenylphosphonium cation (SkQ1) penetrating through the membrane in nanomolar concentrations inhibited H2O2 generation in cells of epidermis of pea seedling leaves that was detected by the fluorescence of 2',7'-dichlorofluorescein. Photosynthetic electron transfer in chloroplasts isolated from pea leaves is suppressed by SkQ1 at micromolar concentrations: the electron transfer in chloroplasts under the action of photosystem II or I (with silicomolybdate or methyl viologen as electron acceptors, respectively) is more sensitive to SkQ1 than under the action of photosystem II + I (with ferricyanide or p-benzoquinone as electron acceptors). SkQ1 reduced by borohydride is oxidized by ferricyanide, p-benzoquinone, and, to a lesser extent, by silicomolybdate, but not by methyl viologen. SkQ1 is not effective as an electron acceptor supporting O2 evolution from water in illuminated chloroplasts. The data on suppression of photosynthetic O2 evolution or consumption show that SkQ1, similarly to phenazine methosulfate, causes conversion of the chloroplast redox-chain from non-cyclic electron transfer mode to the cyclic mode without O2 evolution. Oxidation of NADH or succinate in mitochondria isolated from pea roots is stimulated by SkQ1.
与癸基三苯基鏻阳离子结合的质体醌（SkQ1）以纳摩尔浓度穿透细胞膜，抑制了豌豆幼苗叶片表皮细胞中过氧化氢的产生，这一过程通过2',7'-二氯荧光素的荧光检测到。SkQ1在微摩尔浓度下会抑制从豌豆叶片分离出的叶绿体中的光合电子传递：在光系统II或I作用下（分别以硅钼酸盐或甲基紫精作为电子受体）叶绿体中的电子传递比在光系统II + I作用下（以铁氰化物或对苯醌作为电子受体）对SkQ1更敏感。被硼氢化钠还原的SkQ1会被铁氰化物、对苯醌氧化，在较小程度上也会被硅钼酸盐氧化，但不会被甲基紫精氧化。SkQ1在光照的叶绿体中作为支持从水中释放氧气的电子受体无效。关于光合氧气释放或消耗受到抑制的数据表明，SkQ1与吩嗪硫酸甲酯类似，会导致叶绿体氧化还原链从非循环电子传递模式转变为无氧气释放的循环模式。SkQ1会刺激从豌豆根部分离出的线粒体中NADH或琥珀酸的氧化。
